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GROWL WOOF

2007-01-25T18:53:00.000-05:00

SNOW WEENIES OF THE EAST COAST -- REJOICE
DT IS CLOSE TO BARKING AND LETTING LOOSE THE HOUNDS OF SNOW ..

As I go about explaining why I am about to bark I have set up key premises. Yesterday I made the following statement in the blog.... and it is really important you read it so you understand how the pattern is going to change at the end the month in such a manner so that there is likely be a significant winter storm over the East Coast of the US. Please read this statement carefully

from yesterday
You see the main problem have right now is that all the shortwave activity coming out of STJ / southern branch is over northern portions of Mexico and S Texas. In the current flow... and in the pattern over the next 7 days... these S/Ws cannot Gain enough Latitude so any surface development is over the Northern Gulf and the Lows end up sliding off the SC and GA in ENE direction.

However if we do enter the process undercutting the Ridge in the last few days in January and early FEB this will (as I said) establish a Split flow pattern. And more importantly the S/ws coming in across the Southwest will have enough time and distance to gain latitude as they head E or ENE . In other words IF you have a shortwave over the SE Texas that tracks in a 060 direction (ENE) it's going to slide out to sea as will the surface Low. The same track however with a shortwave which is starting back over the Southwest... well now you are in a different ball game.

Recall the weak Low that moved off the NC coast this past weekend ? Originally that Low was played up as 1st decent moderate snow for Middle Atlantic... yes several days out I did that as well. The reason? Most forecasters could NOT believe the pattern which has featured the prominent and very strong Southeast Ridge for the past 75 days would suddnely give up so quickly. But that is exactly what has happened.

That is why the shortwave which came through with the Northeast states on the Arctic front today is going to form a big Low so far out to sea because ....there is no Southeast Ridge to keep the Low closer to the coast.... That is why the area of Low pressure develops the Northeast Gulf in 60 hrs and moves off the GA SC coast in 72 hours is NOT going to climb further up the coast.... because there is NO Southeast Ridge.

The pattern change over the past 5 days has been so complete so massive and the PJ has become so dominant that any sort of Low that develops in Eastern Texas the Delta or along the Gulf Coast is quickly whisked out to sea....because we have no Southeast Ridge !!! and because we have no sustained negative phase of the NAO.
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/nam/12/fp0_060.shtml

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/nam/12/fp0_072.shtml

This pattern is NOT going to change unless something makes it change. We also have to keep in mind that we have no hint at all on a -NAO on any of the models. The PNA ridge is so massive and strongly positive and the flow is simply too fast to allow any sort of buckling in the jet stream over the North Atlantic to support a -NAO.

This leads to two important problem with respect to getting snowstorms for the East Coast. Right now in this pattern all the Arctic High-pressure systems are dropping down from western Canada into the lower Plains. At that point the Polar Jet tuns ENE so the HIGHs scoot across the Deep South then move off the Southeast coast. This of course shuts down the Gulf of Mexico as well as force the fronts deep into the Gulf. Low pressure areas are NOT forming over AL or TN but over or near New Orleans or in the North Central Gulf.... and in this flow that means Out to sea!!

As I stated yesterday there are only TWO ways to get out of this trap.
One way is to to have the S/Ws in the southern stream start out further WEST --- such as the Southwest states or perhaps even the Central Plains so that the same ENE flow of the PJ ....-whch has been taking these Gulf Lows off the SC coast and out to sea ... is now taking these Lows into TN and NC / VA. In this possible solution to the snowless trap for the Eastern US the overall pattern has not really changed .... what happens is st that the hypothetical shortwave which triggers the surface development is starting out further to the North and the West so it simply has more time to gain latitude.

TWO the Other solutioin is to have more and more energy coming over the top Ridge in western Canada plunging into the Plains states which forces the trough to become very deep and very powerful.... taking on more of a V shape then the broad U shape than what the trough is now in.

We can see many of the medium-range models are beginning to develop the second solution quite nicely. Here is the0z Thursday GFS at day 9 at 500 MB... and what has happened is a whole new surge of energy has dropped in from over thetop the Ridge on the West Coast of North America and has forced the trough into a large EGG shape.... with the bottom or rounded point of the EGG reaching into the central and Lower Mississippi Valley. This of course generates some sort of Llow pressure area developing over the Mississippi Valley or perhaps Tennessee Valley... but because it starts out at a further north latitude the whole system gets to track further to the North which brings the threat of significant winter to much of the eastern US.

http://weather.unisys.com/gfsx/9d/gfsx_pres_9d.html
http://weather.unisys.com/gfsx/7d/gfsx_500_7d.html
http://weather.unisys.com/gfsx/7d/gfsx_500_9d.html

At first glance one might argue that this pattern amplification could be an over reaction from the op GFS since it occurs after the model truncate at 180 hours and often that is when the model comes up with some thing that is goofy. However the 12z Thursday op GFS closely matches the European from Wednesday as well as the European runs from today...
many of the 0z GFS ensembles strongly supports the operational run ... pay attention to the particular members.
p01 p01 p05 p06 p07 p08 p09
http://www.meteo.psu.edu/~gadomski/ENSPRS_0z/f180.html
http://www.meteo.psu.edu/~gadomski/ENSPRS_0z/f192.html

The 12z op GFS continues this trend; you see what is happening here that this huge surge of energy coming over-the-top the Ridge in western North America is forcing the PV --polar vortex -- to drop dangerously far to the south by D10. Again this is NOT a recent model development but a trend I have been seeing since Since 0z WED and even some hints before that. Take a look at the three maps below -- at 500 MB -- from the Midday Thursday 12z GFS and notice how the vortex is being dragged into Manitoba.

What this does is
1) bring in even More Arctic air to dominate most of the nation especially east of the Rockies... 2) establishes the mean trough over the Mississippi Valley.... which is WEST of where it is now.

Because you have the mean a trough position over the Mississippi Valley you must also have a downstream Ridge developing which in this case is over the Southeast and Middle Atlantic states. Thus any sort of Low pressure area which develops in the Delta is forced to take more of NE track as opposed to E or ENE.
This is exactly what happens here at 192 and 204 hrs on the midday Thursday Op GFS as well as many of the other medium-range models.
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/fp0_168.shtml
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/fp0_192.shtml
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/fp0_204.shtml

More significantly the European runs are very consistent over the few cycles... and closely matches the0z and 12z operational GFS . Day 6 and Day 7 --- again notice how the overall trough and Day 7 sharpens up dramatically http://www.meteo.psu.edu/~gadomski/ECMWF_12z/f144.gif
http://www.meteo.psu.edu/~gadomski/ECMWF_12z/f168.gif

I have seen the operational European past Day 7 and the model develops a significant TRIPLE point Low area over the Tennessee Valley that moves ENE off the coast of VA or Northeast NC at day 8.5 or 9. I think that is a little too far to the south but it's the general idea in the overall sense.

The midday GFS ensembles are very supportive of the operational solution as well.... with many members showing a significant system tracking east Northeast off the VA or NC coast... some of the members have a more Northeast track.

The critical issue is going to be what shaped as the trough move into after Day 6? According to most of the medium-range models the broad U-shaped trough is going to change into a much sharper and elongated elliptical trough . If that happens then when Low pressure forms over the Delta it will be able to track further up the coast than the last several systems and there will be a significant snowstorm for much of the East Coast.

http://www.meteo.psu.edu/~gadomski/ENSPRS_12z/f192.html
http://www.meteo.psu.edu/~gadomski/ENSPRS_12z/f204.html

that being said to me also emphasize again that is a very fine line we are going to have to walk with the system along the East Coast. Take a look at the 12z Day 8-10 op Ecmwf and op GFS maps... they both show a huge amplified trough whopse center or axis is over or along the Mississippi vally.

http://www.meteo.psu.edu/~gadomski/ECMWF_12z/hgtcomp.html
Because we are not going to have a large cold HIGH to the North and we do NOT have a -NAO temperatures are going to be very critical and very sensitive along many of the I-95 cities in this event FEB 3.... ASSUMING of course it does develop. If we end up getting too much of Ridge over the Southeast the Low will track further north so iot will be more of a snow to ice to rain set up for the big cities of I-95.. On the other hand If we don't get enough of a Ridge the Low stay south and much of the snow and/or ice will fall across places such as TN NC and VA .

Lastly as a move in February the solution offered by the midday operational GFS at day 10 seems very reasonable to me and it is supproted by the 12z GFS ensembles
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/fp0_240.shtml
http://www.meteo.psu.edu/~gadomski/ENSHGT_0z/f240.html

Hey Baby it do what it do

2007-01-24T17:13:00.000-05:00

The great philosopher and musician Ray Charles was once asked in interview how his music appealed to so many different groups of people... ethnically economically racially... and he said "Hey baby it do what it do..."

Which is really when I think about it sort of a variant on the philosophical underpinnings of Aristotle Marcus Aurelius and Dr. Hannibal Lecter. Of each thing we muts what does it do? what is its nature? What is its significance?... How does this exactly relate to the current pattern we have have over North Ameica? Well it's kind of entertaining watching the various forecasting services and a few individual forecasters continually try to assert that the new cold pattern is not really going to be all that cold... which is what they were saying last week or that it isnt going to last all that long.... then in the very next sentence forecast the cold pattern is now going to last into Midle of February ...but THEN it breaks down...

"Hey baby it do what it do..."

I think it's a little harsh to assert that such a warm biased forecast for second half of FEB and March is delusional but for life for me I cannot understand what the REASONING is behind that sort of call. The El Niño continues to weaken at a dramatic pace and surely even the most hard-nosed stubborn warm biased forecasters have to see the significant difference between the pattern of November and early December and the current pattern and what we will likly see in early FEB. Just like the data is strongly correlates that when you have moderate / strong El Nino you have a mild winter pattern in North America... it is equally strong that when you have weak El Niño conditions you end up with a colder to much colder than Normal over the central and eastern CONUS.

We'll start by taking a look at the operational GFS at 1am WED... as you can see there a pretty strong shortwave which is crashing underneath the Big west coast Ridge. This is a process known as undercutting and allows the Ridge over the West coast of Canada to become a OMEGA RIDGE or a REX BLOCK.
http://weather.unisys.com/gfsx/7d/gfsx_500_7d.html

Note the 2 S/Ws... one coming into N Calif and Oregon and the other dropping south from western Canada about to enter eastern MT.

This process is called undercutting and IF it does in fact occur then we are going to significantly increase the chances for much of the central and eastern US seeing a snowy pattern as a month comes to an end and we move into February. But first the Undecutting has to occur. Seeing it a model is NOT the same thing as reality.

It do what it do ...

The undercutting process will SPLIT the flow which would significant increase the activity in the STJ/ southern branch which of course leads to increased chance of seeing systems develop either in the lower Plains and Deep South and NOT the Gulf Coast.

You see the main problem have right now is that all the shortwave activity coming out of STJ / southern branch is over northern portions of Mexico and S Texas. In the current flow... and in the pattern over the next 7 days... these S/Ws cannot Gain enough Latitude so any surface development is over the Northern Gulf and the Lows end up sliding off the SC and GA in ENE direction.

However if we do enter the process undercutting the Ridge in the last few days in January and early FEB this will (as I said) establish a Split flow pattern. And more importantly the S/ws coming in across the Southwest will have enough time and distance to gain latitude as they head E or ENE . In other words IF you have a shortwave over the SE Texas that tracks in a 060 direction (ENE) it's going to slide out to sea as will the surface Low. The same track however with a shortwave which is starting back over the Southwest... well now you are in a different ball game.

By day 8 on the 0z op GFS ... the two s/w... are GONE because the op GFS past day 8 suffers from Model resolution truncation ... which is a fancy way of saying the model past day 8 blows Chunks .
http://weather.unisys.com/gfsx/8d/gfsx_500_8d.html

The 0z day 9 and day 10 ECMWF with its vastly superior model resolution has NOT lost these two S/Ws and this results in a pretty good over running pattern by Day 10.
http://wxrisk.com/MODELFOLDERS/today/jan24/1920zEU5h.gif
http://wxrisk.com/MODELFOLDERS/today/jan24/10D0zEU5h.gif

The midday WED 12z GFS has caught on to this trend and is now showing these two S/Ws in a much better depiction. The shortwave which undercuts the Ridge near Oregon / N California is much stronger at D6 but of course the model resolution is still pretty good. At 192 hrs... when the model resolution is truncated we can see that the midday operational GFS has two fairly strong shortwaves but the southern S/W appears to be getting stuck over the southern Calif/Vegas area. Not surprisingly given the bias of the operational GFS the model put all its emphasis on the shortwave that stopping into the coat is at 192 hrs ... and it is this feature which develops a system for D9.
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/images/gfs_slp_216s.gif

The midday ECMWF at day 7 again is showing significant activity over the western CONUS with two very distinct and powerful S/Ws. The Midday at day 9 does show some sort of triple point surface Low that brings a pretty decent amount of snow to the Tennessee Valley & Middle Atlantic states... followed by a bitter Arctic out break at D10
http://wxrisk.com/MODELFOLDERS/today/jan24/7D12zEU5h.gif
http://wxrisk.com/MODELFOLDERS/today/jan24/9D12zEU5h.gif
http://wxrisk.com/MODELFOLDERS/today/jan24/10d12zEU5h.gif

this idea is supported by the 12z Op GFS as well .
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/images/gfs_500_240s.gif
http://www.meteo.psu.edu/~gadomski/ENSHGT_12z/f240.html

One last note... the 0z op GFS at 312 hrs was trying once again to knock down the Ridge over old western North America trough and develop a flat Ridge over the Southeast which of course end the cold pattern east of the Mississippi River.

But we can see from this link most of the ensembles 0z data does not support that idea at all
http://wxrisk.com/MODELFOLDERS/today/jan24/0z5hf312.gif

nor does the 312 hr 12z ensembles mean. As we can see the white lines are showing the operational run and the trough trying to reform at West while the fMost of the members show the trough staying strongly over the eastern North America
http://wxrisk.com/MODELFOLDERS/today/jan24/f312.gif

hey Baby it do what it do

COLD then NOT cold... COLD then NOT cold

2007-01-22T16:38:00.000-05:00

FIRST
how will start off with a review of the weekly ESNO data. There are two primary sources that most forecasters use in terms of getting the weekly data from the various ENSO regions. The first one is from CPC.. and there ENSO weekly SSTA numbers comes out every Monday. The cycle runs from Thursday to Wednesday but for some reason it takes five days for the CPC to get the data published to the web site but you can see here.

http://www.cpc.ncep.noaa.gov/data/indices/wksst.for

the other primary source for ENSO data is Australian Bureau of meteorology which also issues weekly reports on the variouis ENSO regions.
http://www.bom.gov.au/climate/enso/indices.shtml

However the AUSSIE data cycle for the enso regions runs from SUNDAY to SATURDAY but they manage to get their data on to their wenb site in TWO days.... not Five. WHY this is the case I dont know.It is NOT my fault. The point is that since the Aussies data cycle goes much later in the week I think that it's data is more liable and a more accurate.

In other words suppose you has two models to consdier.. one from last night and then the latest run. Which one would you prefer to put more emphasis or reliability on (assuming the data in both models was the same?) Clearly you would prefer to or favor of the most recent model as opposed the one from yesterday with a day before.

Last week showed CPC has ENSO 3.4 region SSTAs were holding at +1.0C but the e Aussies showed a drop from +0.92 to +0.83 ( about -0.1 degree C). It's probable that the reason that CPC did NOT show that 0.1 drop.... is because the drop occurred in the THURSDAY FRIDAY SATURDAY period which would be after the cutoff time for the CPC data cycle.

As of today the Aussies weekly ENSO 3.4 dropped again from +0.83 to +0.67. Hhowever... if you look at the first link above you'll notice that as of JAN 20 CPC shows a drop IN ENSO 3.4 from +1.0 to +0.6... which is huge WEEKLY drop.

One of the claims that some forecasters were arguing back and forth during the months of November and December was that there was a difference a quality between the data from the climate prediction Center and the Aussies. But as I have explained part of the discrepancy is because the data cycle. And this case we did not really see a drop of -0.4c in 1 week in ENSO 3.4. Instead the data at CPC is playing "catch up" to what Aussie data.

The reason why I mention all of this is because I think any reasonable person can now conclude that there is no significant difference between the data onENSO SSTA between the Australians and CPC.

I will briefly touched on the former snowstorm threat for FRIDAY January 26. There really isn't much more to say. The operational GFS and the GFS ensembles were wrong and the other medium-range models and their ensembles were correct. As a general rule there are very few times when you have a case where one particular set of models ( such as the GFS and the GFS ensembles or say the CMC or CMC ensembles) show one particular event while the other models have no hint of it... only to see the GFS turn out ot be correct.

The reason for this is that the models especially in the MR and LR are now so good that when you have MODEL... lets call it MODEL XYZ is showing an event which is not supported by Models B C D and E even though the potential threat is getting closer... that should be a warning bell to you that something is wrong. Typically what happens is that when MODEL XYZ is showing an event at day 4 5 6 or 7 ... suaully within a run or two SOME of the various other Models will begin to shift IF MODEL XYZ was correct to begin with!!!

Typically the artgument then becomes WHERE the Low is going to form OR how far north as going to track OR where the ridge is going to set up.... etc etc. But over the past several days the problem was the operational GFS and many of the GFS ensembles is that they were the ONLY models that showed the JNa 25 storm tracking that close to the coast . None of the other models had even a hint of the major storm for East Coast. That's a totally different kettle of fish.

One of the problems we have with the current pattern --as I talked about on the Saturday evening update -- is that if you look at the upper air at say 500 MB you will see some important features as to WHY the system on Thuirsday develops off the coast on Friday.

The first is that the Ridge which we typically want see on the West Coast is not really there but well inland over the Rockies... which is kind of Far East.
This means that the PV position in eastern Canada is also to be East. Thus any sort of wave which is moving into the trough position aong the East coast is going to develop EAST of the coast. If the trough position was say back by 80° west longitude THEN we would have a much bigger snowstorm threat for the Northeast. But again because of the Ridge on the West Coast is now over the Rockies everything shifted to the east... and hence the development well off shore.

Let this be a lesson to you. It is not simply a matter of getting the right overall pattern at say 500 MB or 700 mb or 840 mb... but the system also has to develop in a fairly narrow area to bring significant or heavy snow to the mid-Atlantic and the New England region.

Once the system is off the NE coast on Friday Arctic air mass will plunge into the Midwest and Northeast US with strong N winds. As long as we keep that strong West coast Ridge then ther wwill be a series of srong cold Arctic HIGHs that will drop down into the central lower Plains then going east across the Deep South. This does two things... first shuts off the Gulf of Mexico as any moisture sources along the Gulf coast. Second er once these Highs reached the South East Coast and move off ... winds will turn around to Wes direction for bringing a day of mild temperatures over the Plains and Midwest and the Northeast before the next Arctic blast passes through. Essentially over the next 10 days we are looking at least three arctic cold fronts will into the Midwest and the Northeast.

The last point I want to bring up is the the last couple runs of the operational GFS. I think it should be obvious at this point that any attempt to break down the cold pattern and the monster Ridge over the west North America is ludicrous and most skilled forecasters should be all to detect bullshit when they see it on a model.

Here is the 0z GFS at 312 hrs and as you can see ... the strong West Coast Ridge is either been destroyed or cut in half by the powerful Pacific Jet. And if this work to turn out to be correct it might have implications for the entire pattern with some sort ridging developing over the Southeast.
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/00/images/gfs_500_312s.gif

We see the same sort of pattern at 6z and again at 12z Monday in the week 2 time frame.
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/06/images/gfs_500_312s.gif
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/images/gfs_500_324s.gif

However even a cursory glance of the ensembles shows how obsolete ludicrous this idea is as the overwhelming amount of model data from the 0z 6z and 12z GFS ensembles show the Rudge on the West Coast holding.

For example this link from the 0z run compares the white lines which represents the operational run of the GFS to all the other ensemble members. As you can see from the various blue red and green lines there's no support for the operational GFS trying to develop the trough over the West Coast and knocked out of Ridge.
http://www.meteo.psu.edu/~gadomski/ENSHGTAVGNH_0z/f312.html#

Likewise we can see the same thing at the 6z GFS--- again note how the white lines are a huge model outlier when compared to what most of the model members are showing.
http://www.meteo.psu.edu/~gadomski/ENSHGTAVGNH_6z/f312.html

And this continues at 12 see on the operational GFS as well.
http://www.meteo.psu.edu/~gadomski/ENSHGTAVGNH_12z/f324.html

SATURDAY NIGHT SPECIAL -- bang bang or woof woof ?

2007-01-20T20:19:00.000-05:00

This is a special Saturday early evening report and I'm going to be talking mainly about the potential for a SECS / MECS event that has a lot of people all of buzz for Jan 25- 26.

Just remind y'all a S.E.C.S. event = Significant East Coast Snowstorm is something like a typical 4 to 12 " snowstorm...
a MECS = major East Coast Snowstorm such as widespread 8 to 16 inch snowstorm and a HECS which is a Historic East Coast snowstorm is something like a widespread Snowstorm that has 10 to 20 inches of snow with areas > 20 inches in the I-95 Metropolitan corridor.

I know that JB's been banging the drum here for several days as have I and several other well-known forecasters with regard to January 25... certainly the potential is there for a SECS or MECS event but I for one am NOT yet convinced that this event as shown by the last several runs of the operational GFS and the GFS ensembles is going to take place as those particular models are showing.

In other words in dealing with the time frame we are-- the event is still five to six days away-- we could end up with a large intense LOW off the East Coast but not close enough to produce any sort of significant or heavy snow except for perhaps far eastern New England... and yet because we are still dealing with five to six days in time at that medium-range it would STILL count as a "HIT" or a "good" forecast by the medium-range models.

Of course if you are all excited -- like I am -- about this possible event and you think that the GFS is going to verify correctly and you a may be salivating at the propsect of 12 inches of snow at your house.... well thats great. BUT suppose the other MR are correct... and we get a Big Low off the East coast but say 200 or 250 miles further to the east... well you are going to hear alot of bitching and complaining no end from the general public as well as weather hobbyists and weenies.

You see this is the risk that one pays by banging the drum so convincingly and so loudly. Moreover I can tell you that this is a source of considerable frustration with a lot of meteorologists... and if you are a weather hobbyists or member of the general public I don't think you fully understand the frustration that many of us feel the private sector. Just because one forecast or well known private forecaster Company happened to be on the Cable news a lot doesn't mean that I have to take the blame if your forecast goes wrong.

IF these other medium-range models turn out to be correct and those banging the drum for the big snow in the NE (like the GFS and GFS ensembles are showing) turn out to be wrong those forecasters like me who will have urged caution will be ignored even though we turned out to be correct.

The only thing that the public as well as weather weenies are going to remember if this event does NOT happen is that JB and a few other forecasters have been letting the BIG dog bark. And suddenly every single meteorologist will be viewed as have made the same forecast. The distinction between those who are making the big snow forecast and those who were not will be lost.

Interestingly when I used to post on some of the weather forums on this very point .. that there is reason why sometimes there is a little animosity between the various private forecasting companies and individuals... a lot of the more ignorant and slopeaded folks out there have the viewed this argument as nothing but jealousy or sour grapes.

But it does not matter whether we are talking about weather forecasting or taxes or medicine or stock trading... when you end up getting blamed for somebody else's mistake while at the same time u work tirelessly to show that you didn't agree... well that can really piss you off.

In taking a look at the 12z SAT op-GFS... this 500 MB map has a lot of features to talk about. And one of the main points I want to make is that even when you have all the pieces or almost all the pieces you need to get a snowstorm (with regard to the Upper Levels of the atmosphere) ... things can STILL go wrong. That's why is so difficult to get the "big dog" off the leash.

This map shows several features...
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/images/gfs_500_102l.gif
yes we do have a 50-50 low in position. It's not the greatest 50-50 low full-time but it's definitely there. We have a nicely situated PV ... a fairly strong Ridge on the West Coast/ Rockies... and we appear to have phasing occurring between the strong system dropping in on the northern branch and the remains of the system coming out of Southwest. In addition the phasing was occurring over the Mississippi Valley which is ideal and the trough alignment or axis is NEUTRAL....

So what seems to be the problem? And why aren't the other models picking up on the op GFS and GFS ensembles?

Well this is one reasons why I am not a big fan of using the operational GFS for forecasting East Coast snowstorms. In the early outlooks ... say Day 7 thru day day 10 the model often ends up crushing systems in the STJ/ southern stream which is what the Op GFS and many of the GFS ensembles were doing just a few days ago. Now that we are within the Day 7 time frame the cold bias of the model and the ensembles manifest itself in a different manner.

Now we see the same tendency in the current runs of the model and again this applies to the GFS ensembles just as much as it does the operational run... to over phase and / or over develop systems. So while we can use the GFS ensembles in some ways... all of them have the same problem that the operational run does. So when you look at the 12z Saturday GFS ensembles and you see eight of the 11 members strongly supporting the idea of a major Low off of the Delmarva or New Jersey or off the Southeast New England coast Jan 25... they all may be showing the same problem/ affect if the cold bias.

The midday as well as the 0z SAT op ecmwf does not show the northern branch dropping in phasing with the southern system.

WHY? The Europeans hang in the southern system back too far and as a result there is no phase and the primary Low develops only from the northern stream shortwave so what we get is the ocean Low off Cape Cod or the Gulf of Maine.

This is what the 0z and 12z Ukmet is showing as well as the last few runs of the operational CMC.

As a general rule I like using the European model over the operational GFS because of these various bias problems that the model has. However over the last two years the advantage that the European models has shown historically has now disappear in the 24 to 168 hr time frame. And the best-known case of this has to do with the HECS event from ast year for the Northeast and specifically New York City. If you recall the European model DID show the Low nut had the Low further south.... while the GFS was correct once we got within 72 hours showing the Low further now along with the stalled comma head snow band. That being said I must also point out that the operational European at least did have the Low. We did not see this sort of huge model disparity that we seeing Now.

There is no reason one way or the other to be particularly optimistic or pessimistic at this point. This evening is another run and tomorrow is another day.

NE USA winter storm threat for Next week JAN 25???

2007-01-19T12:43:00.000-05:00

In dealing with the next 2 POSSIBLE winter events for the Northeast we have to keep a few things in mind.

The system that's coming out of the Southwest today in this weekend is come in providing major snowstorm for places that don't normally see at such as Northeast New Mexico Northern Central Texas Oklahoma and even significant snow into places such as northwestern Arkansas and Missouri.

The big issue with this first system is how fast does the upper level support --also known as a shortwave --weaeken as it comes east over the top of the flat Ridge over the southeast states.
Take a look at the short-range models humidity or the Rh fields and you'll see what happens.

The precipitation breaks out into the central Plains over places such as Missouri Illinois and Indiana while the is precipitation along the final S end of the front gets hung up over the Tennessee Valley. The northern edge of the precipitation kicks out of rapidly thru the the Middle Atlantic in a 6 -10 hr period .. while the Southern end of the front gets stuck over the SE states and there it will be mainly rain (or Ice over NC).

There is is some slight northward movement with the main surface low on some of the short-range models and that North Trend may continue. But unless the entire system is shifted North over the next few model runs that we're not looking at a significant snow over Northern Virginia Maryland Pennsylvania Delaware and New Jersey.

With regard to the bigger threat for next week. I know that one of the more popular forecasters in central Pennsylvania appears to be banging the snow drum pretty hard with regard to the event for January 24 --25. That may be correct but there's a lot of problems here which we have to work out and I'm not get one to go that far out on a limb given deal hall problems for having with this pattern.

There certainly is a good possibility that there IS going to be a major LOW pressure area somewhere along the East Coast but the whole system may also form too far off shore for many areas in the NE to see good snows. It is also possible the system may form along the NC coast and affect a much larger region of an Atlantic. So rather than be the first and the loudest and most extreme I'd rather the second or third and get it right and have the reputation that if I think its coming... there is a pretty good probability it is.

I'm presenting a couple maps here to drive home the complication we have what he system for January 25. Hhere is the bottom line: If the system in the Southern Stream or the STJ / subtropical jet holds together when it comes out early next week I'll cost Texas in the Delta... then the event that develop some East Coast as a very good chance of being a MECS or HECS.

If on the other hand the Southern system is crushed or ripepd apart then when the Northern shortwave drops into the Midwest on the PJ/ polar jet and middle of next week... we will end up with no facing off the two streams and bull had is a significant storm for New England... aka known as a MILLER B... and places such as Philly DC MD VA central PA and lower NJ would see nothing significant.

This first series a maps shows the problem very nicely... from the 12Z the run on Thursday. You can see clearly the shortwave looks very strong in the Southern branch over New Mexico and Western Texas AT 120 HRS .

http://wxrisk.com/MODELFOLDERS/today/jan18/12gfs_500_120s.gif
http://wxrisk.com/MODELFOLDERS/today/jan18/12gfs_500_144s.gif

By Day7 we can clearly see what has happened. The Southern shortwave gets ripped apart completely and there is nothing really left to develop at the surface .
http://wxrisk.com/MODELFOLDERS/today/jan18/12gfs_500_168s.gif

Since the upper level feature and the shortwave has been ripped apart the only development we see is a weak area of Low pressure that forms along the Florida Panhandle or Southern Georgia which quickly scoots out to sea
http://wxrisk.com/MODELFOLDERS/today/jan18/gfs_slp_144s.gif
http://wxrisk.com/MODELFOLDERS/today/jan18/gfs_slp_168s.gif

As I stated d yesterday the key point here is the cold bias of the GFS and whether or not in this synoptic pattern the bias is kicking in and to what degree . As I explained in this synoptic pattern the cold bias is very evident and is likely be a major problem. We can see is by looking at the 12z THURS GFS ensembles.

This first link of course it is the 500 MB maps... as you can see many members to showing much stronger system over Texas and/or the Delta but some members also keep the South West shortwave hanging back with no phasing at all .
http://wxrisk.com/MODELFOLDERS/today/jan19/f132.gif

The surface Maps all showing much stronger system over the Gulf Coast area with a lot more significant precipitation. Some of the solutions to show significant phase some of them did not. In short data is inconclusive but there is reason to believe that the midday Thursday op GFS is mishandling the Southern system significantly.
http://wxrisk.com/MODELFOLDERS/today/jan19/f144.gif

The midday European of course shown a much bigger more organized East Coast low pressure area at a Day 6-7. And again the reasoning here has not changed from the Thursday Blog entry; as a general rule European model does very well with strong shortwaves moving through the Southern branch / STJ. And since there is more energy in the Southern branch you have more potential for storm on the East Coast January 24 --25. It's just that simple.

Interestingly the 18z GFS from Thursday showed how dramatically the op GFS can change in just one run. As I stated many times I do not like the 18z op GFS as statisticallu the data has proven conclusively (but for some unexplained reason) that the 18z op GFS is the least accurate of all for all the operational GFS runs. However in this case I'm referring to the 18z GFS to show that the European solution from yesterday as a some validity and also to show the impact of what could happened if the system coming out of the Southwest does not get sheared apart.
I have seen the FRIDAY 12z operational GFS; of course it rips up the system in the southern branch so there's nothing left to phase when the northern shortwave drops down at 120 HRS over the Midwest. This results in essentially a classic Miller B or secondary redevelopment type of MECS / HECS event for New England. The system according to the model actually closes off on very close to Cape Cod for almost 24 hours pounding much of New England with heavy snow... in a manner very similar to February 1978.

And as is the case with 90% of all Miller B SECS / HECS / MECS areas such as Baltimore DCA MD VA DE and possibly Philly and Southern New Jersey misses out on the best or heaviest snow.

Again let me emphasized that if the Southern Energy comes out as an intact feature then the 2 short waves are likely to phase and instead we could see a closed off Low over eastern NC or just off eastern NC.

Of course you have to check the midday GFS ensembles and also you could keep in mind that is not a good thing as a general rule to be in the bull's-eye D6- D8 out. The event on January 25 if it occurs would be on the weekend ... and this event would affect the synoptic pattern in keeping the deep rough over the eastern US right to the end of the month.

In fact the 0z European ensembles are very impressive with the Ridge over the West coast holding to D15 ... and the long-range European weekly ensembles continue to show the trough over yeast in US right to the middle of February.

box of Biscuits a Box of Mixed Biscuits and a Biscuit mixer

2007-01-18T17:23:00.000-05:00

the 1st issue to deal with is the s/w coming out of the sw states into the Lower Plains and Midwest this weekend and what it means for East coast with regard to Sunday and Monday.
There are some important changes in the midday models very early in the medium-range period -- Sunday night and Monday. The first major change is that the arctic HIGH which comes down after this cold front on Friday and Saturday does NOT drop y into the Lower Plains and instead it stays across the central Plains then heads into the Great Lakes and New England. This means that the cold air is going to be further north and the threat for significant snow and ice over Central and the lower portions of Texas as well as the upper Delta is greatly diminished. NM OK and north TX as well as MO look to see a good snow.

In addition most of the short-range models now show that the shortwave comes out of the Southwest further north. Yesterday that was taken a system to Missouri now it takes that of the northern Missouri Southern Iowa and very close to Chicago.

The primary reason for this shift has to do with the southeast ridge and eight another stronger shortwave which drops down from Weston Canada along the Rockies into Arizona and New Mexico this weekend in early next week.

Because you have one piece of energy dropping from north to south ...that is to say from the northern Rockies into the Southwest states you HAVE to get a corresponding reaction to the flat Ridge over the Gulf coast of Florida and that reaction will be to see the southeast Ridge expand a little to the north.

As a result the threat of winter precipitation with a system for the Tennessee Valley and lower portions of both NC and northwestern SC is greatly diminished in my opinion. Oh there maybe some BUT it does not look like a big deal at this point.

the model trend is clear to me... the strong s/w that comes out of the sw state that then gets crushed once it reaches Mississippi roiver is going to develop NOT a east coast Low per se... but it is an over running.

It is time for Me and others to make clear that this Sunday night Monday is NOT a coastal Low or major snow ... The only reason this event is going to be SIGNIFICANT is that its the 1st one of the season...

Not surprisingly the mid day Thursday GFS of courses screws this up since the cold air bias makes the model essentially useless this far out in time. Even though we can clearly see that the shortwave is now further north than what the model was showing yesterday and the Ridge over the southeast a little stronger somehow or another the model still takes the surface reflection of low well south of Cape Hatteras which of course makes no sense in all.

Actually I think the midday Canadian is probably the best are most reasonable with this solution regarding Sunday night and Monday
http://meteocentre.com/models/gemglb_amer_12/gemglb_amer_12_panel.gif

The next major problem have to deal with is that big shortwave I talked about above dropping into the Southwest states late this weekend and early next week. It certainly has the potential to bring another significant snowstorm to the central Rockies as well as a Denver area But the issue is that the MR models are having real trouble figuring out what to do with the shortwave.
http://www.nco.ncep.noaa.gov/pmb/nwprod/an...2/fp0_096.shtml

For example the midday GFS has another piece of energy coming in on the northern branch which ends up crushing the shortwave in the southern branch and we end up with a sheer ZONE axis ... in a SW to NE direction tracking through the Deep South and Tennessee Valley. This means that the only wave / LOW development can occur over the Florida Panhandle or perhaps far southern Georgia and the low scoots out to sea by the end of Next week
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/fp0_144.shtml

as you can clearly see from this map at 144 hours... IF the southern s/w were to come out intact and NOT get sheared apart AND we do in fact have that next strong shortwave in coming down from Central Canada in the northern branch... the potential exists for significant winter storm on East Coast. I am confident that the operational GFS is ripping up the southern system too rapidly and therefore I reject the solution as shown on the Thursday midday operational GFS.

In addition most of the GFS ensembles which also still have the cold bias are mishandling this southern shortwave so most of their solutions are not viable in my opinion.

However the midday European does not have this problem and since it handles systems on the southern stream far better than he GFS we end up with a phased development.
The European keeps the coastal ffront which develops from the Monday system along the Southeast and middle Atlantic coast . Because the model handles the southern system differently we end up getting a significant coastal Low that forms late next week. Of course the issue is how close to the coast will this Low form and will there be enough cold air in place? None of those questions can be answered at this time but because we do have a split flow pattern and we are going to have a significant shortwave hanging back in the Southwest that will come out in SOME form or another the next several days has to be watched very carefully for the potential for winter storm on the NE Coast.

It is also possible that the system in the southern stream might get ripped apart and if that is the case we will end up with a Clipper system moving thru with a reinforcing arctic cold front
the other aspect to the potential for the storm on East Coast late next week is that this Low has major implications for the overall pattern in the last week of January and into early February.... and in particular which model is correct in terms of the Arctic blast after the 25th January.
As you know the last few runs of the operational European as shown a severe arctic outbreak developing after January 25 with the Arctic Airport in all liens isn't the Deep South and 850 temperatures as low as minus for driving into Central Florida.

The European model is doing this because the development of major Low the East Coast that moves into southeastern Canada LOCKs the Eastern trough positioned in place over the eastern half of the CONUS which results in a much colder pattern. That's the next strong arctic high that develops a Weston Canada does not plunge down East southern Rockies but hates into the Midwest and East Coast. The midday European model continues the trend from the last couple of days and develops a bitter cold Arctic air mass that plunges deep into the central and eastern CONUS... with below freezing temperatures plunging into Central Florida by Day 9-10!!!

On the other hand the midday Thursday op GFS does NOT develop a significant NE Low late next week... so the trough over the East Coast is able to slide further off the coast and the pattern is able to relax a little bit in terms of the cold air eastern Mississippi River.

In the week 2 time frame the midday American model Has a couple all the transient troughs that swing through the eastern US with some cold air on Day 10-11 then relaxes the trough of bit only to rebuilds the trough day 14-15 with a severe arctic blast over the eastern conus.
Which one do I think is going to be correct? At this point I don't know although I am far more likely to lean towards the European because as a general rule the European does better with Storms on East Coast and because the GFS solution which is to crush the shortwave in a Southwest when it comes East is most likely not the correct one. It's possible we may getting a big Low in the west of Atlantic similar to what the European are showing ... just a little further to the east. This would still lock the trough in place over the East Coast provided the ocean low would move up into southeastern Canada Labrador.

3 Winter "events" in next 8 days for the NE CONUS?

2007-01-17T16:08:00.000-05:00

I am not going to issue a 1st GUESS or 1st Call forecast for the system Thursday PM into early Friday morning.... primarily because the data at 0z 6a and 12z as well as most of the SREF ensembles show some serious problems. The Low develops on the TRIPLE that forms on the new Arctic front that races east across s the Midwest Thursday. The cold HIGH which EARLY Thursday morning is Over New England is sliding east off the coast...fast. Thus while we do have some WEDGE it is NOT a CAD event.
Anyone who tells you different does know their ass from a Dick Cheney
http://www.meteo.psu.edu/~gadomski/WRFEAST_12z/f21.gif

The cold air ill be a adequate for many locations in the Interior Middle Atlantic to start as snow BUT by Thursday 7pm EST the HIGH is off the coast and we have strong S winds over the Immediate East coast and over MOST of New England http://www.meteo.psu.edu/~gadomski/WRFEAST_12z/f30.gif

Inland -- say ROA CHO IAD HGR LNS ABE the low and mid level S winds will NOT be strong enough to force the warming into those areas BUT those locations will also be too far to the WEST to get any significant snow.

Key word is SIGNIFICANT snow....

In the areas that do see the heavy precip b/c of the Low's explosive development-- eastern new England --the S winds at Low and Mid levels destroy the chances of the precip falling PRIMARILY as snow. The places that see the best chance of seeing SIGNIFICANT SNOW will be CEF CON EEN and much of western ME. Once this system 35N lat by Friday morning it will go BOOM with its MSLP dropping from 1000mb to 972 MB 12 hrs later... 28 MB in 12 hrs so this is not just a boom but a BOOOOOOOOOOM!!

As I stated yesterday the really important aspect to the storm is how it sets up the conditions for the next event which will be on the the 21st into the 22nd. I am very confident now that this Triple point LOW on Friday will in fact undergo explosive development and become a huge 50/ 50 LOW over southeastern Canada this weekend and into early next week. You really have to take a look at the pressure gradient that develops on all the models Friday and Friday night ight over the eastern third of the CONUS. This is some serious CAA action being shoved into the eastern CONUS.

But also leads to problems with how the models are handling the system that comes out of Southwest. If there are 2 immutable laws about weather forecasting point is that the GFS has a serious cold bias which becomes very pronounced when you have cold air outbreaks and some sort of surface Low pressure area that tries to form on the front. The second law is that Hillary Clinton is probably a Dyke. (Okay that really does NOT have anything to do with weather forecasting but it had things to be true)... The last few runs of the OP GFS have been showing the suppressed track which we typically see in Winter systems along the East coast.

You can see from these maps the 500 MB map from the 12z WED at 96 and 108 hrs as the main short wave passing through sent Missouri then tracks over the top of the flat SE conus Ridge thru Lower OHIO...
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/images/gfs_500_096s.gif
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/images/gfs_500_108s.gif

and the 850 Low forms over the lower Midwest near or just the north of the OHIO river and tracks due East across West Virginia and then across central Virginia.
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/images/gfs_850_114s.gif

This should show a surface LOW which is significantly for the north then what the operational 12z WED GFS is showing.
Of course the model is not going to show that at this time range because if ever there was a pattern which would trigger the GFS cold bias to manifest itself well this is a pattern that's going to show it. In fact I would of been shocked IF the GFS had NOT showed a more suppressed flat track off the North Carolina coast at this time range. We can also see from this next map that the position of the Southern low at 108 and 114 hours is significantly too far to the South and east almost over the far sw corner of GA... which makes no sense given the overall synoptic pattern.
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/images/gfs_slp_108s.gif
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/images/gfs_slp_114s.gif

Even so from that point the model takes the system ENE then once the Low reaches the latitude 34N it turns it sharply to the east. Thus one of the things that the operational GFS might be missing here is the flat Ridge over the Southeast. Behind this system comes more very cold air... and the potential for a more significant winter storm sometime around January 25 --26.

The 0z run of the European you can see here takes and other strong /w which drops down over the top the Ridge into New Mexico and far southwestern Texas and phases it with the next strong Arctic shortwave dropping in on the PJ across the Great Lakes. This results in a major storming off the Southeast coast and threatening the Mid Atlantic and New England areas while with a major snowstorm. The 12z GFS does not show this because it takes the s/w that drops in over western Texas and close it off over the Southwest with the operational run showing the 500 Low RETROGRADING off the Southern California coast at 168 -192 hrs. Thus the operational 12z GFS only has the strong northern shortwave and the cold front --- Manitoba Mauler type Clipper diving across the Great Lakes with note the Southern system to face with.

The Midday 12z WED euro is fairly consistent with the 0z run but because it hangs back the energy over the Southwest states a little longer -- again a common bias of the European model-- the phases is not as direct as what we saw on the 0z run and as a result the system takes already organizing makes a wide turn off the Southeast coast at 204 hrs . It's still a significant threat and one should not overreact to the what the 12z WED European model is showing is at 8.5 days out in time. There is very little support from the 12 see GFS ensembles for the European big storm scenario per se but on the other hand only 2 of the 11 members of the 12z GFS ensembles shows a closed 500 low retrograding back into California.

Lastly12z 8-10 day 500 mean shows that BOTH s the operational European and it now the operational GFS a -NAO REX block developing in the area between southeastern Greenland and Ireland. This is assuming that the models are correct would indeed count as a strong - NAO Block.

http://www.meteo.psu.edu/~gadomski/ECMWF_12z/hgtcomp.html

more later

WINTER BEGINS IN THE EAST

2007-01-16T20:45:00.000-05:00

Ever have one of those days where you have so many problems because of your owns success that you just fall behind the matter how hard you try and a stick the schedule?
I still have not made it to the gym and I still No inner yet and this is already 90 minutes late.

If you recall a couple blog entries from way back last week

Saturday, Jan 06 the COMING STUNNING pattern flip
JAN 8 -- The trend is MY friend

In those entries I made two very important points. The first one was that by any definition of terms one wanted to use the pattern was going to flip provided of course if you had a correct understanding what was driving the atmosphere. Over the weekend a well-known meteorologist came out with some specious assertions about what constitutes a pattern change ... and used a certain criteria which nobody ever knew about until he asserted it.

The other important point I made is that it's imperative that one simply does NOT focus on ones own backyard as to whether not there is a pattern change. For example it is of course easily possible for a significant pattern change to occur over North America but at your particular location say the East Coast or perhaps the West Coast the overall pattern in terms of actual weather conditions might not be significantly different. If one were to base their assessment on whether the pattern change simply on own backyard then you got nothing because the criteria is so subjective and professional meteorologists outa to be able to look at things in totality rather than their own backyard.

To drive home the point about how fundamentally different the overall pattern has been and what's it going to be I posted the East to images at another form or I occasionally make an obnoxious comment.... and as you can see these images really speak themselves about how totally different pattern has become.

http://www.wxrisk.com/MODELFOLDERS/today/t-6.gif

http://www.wxrisk.com/MODELFOLDERS/today/abc.gif

JAN 19

The first issue to deal with is the triple point low-pressure area develops on the next Arctic front that sweeps thru Jan 118 over the Plains & Midwest and into the Northeast Jan 19. The NAM / WRF seems to be the most of aggressive with the development of the triple point low close enough to the coast so that it produces the first snow the season along the coastal areas all the Midlantic. Then as the feature movies off the coast and rapidly develops into a major system off the SE New England coast... and much better chance exists for the first significant snow for much of central and eastern New England late on the 19th.

Because we did not yet had any high latitude blocking or a 50-50 low over one-year Newfoundland Canada the surface low that forms on the triple point develops very rapidly and there's nothing to slow it down. In addition of the other problem for the coastal areas of the middle Atlantic is that the boundary level temperatures may be too warm to support all snow.
However what's really important out this feature is what it does as Nows off the coast. First the potential exists for a significant snow storm for New England as this low goes BOOM nar 40 and 70 and points to the north.

But more importantly is that this system plays a critical role in what happens to the NEXT and and potentially much bigger winter storm for the East Coast on January 21 --22.

JAN 21-22

Here is the 1st important rule than or first obstacle that must be overcome as the talk about the next system and its potential to be the first significant what do storm of the East Coast Jan 21-22. IF the Low that is suppose to BOMB out off the New England coast January 19 does NOT do so... the next event JAN 21-22 will NOT be a significant winter storm for the I-95 big cities of the Northeast and the precipitation fall primarily as RAIN.

This map from the midday European shows exactly why this is the case. The first map is the 120 hour European which shows the system from January 19 has now bombed out off th New England coast and we have a deep close cut off 500 Low over southeastern Canada - a classic 50/50 Low.
http://www.wxrisk.com/MODELFOLDERS/today/12z120ec.gif

That Low feature does TWO things. After the cold front comes through in the 19th in the new Arctic High slides into the eastern US the 50-50 low blocks the cold High for moving rapidly off the coast and more importantly establishes a strong PJ in a CONFULENT flow across the Great Lakes and far northern New England. This becomes the cold air source for the Arctic high over northern New England Jan 20-21.

It is for these two very important reasons that the next system and its potential for Bringing a significant winter storm toi the NE is heavily dependent upon the first Low of the New England coast on January 20 bombing out.

Parenthetically at 72 hours the midday Euro does not have a significant system forming on the triple point over the Middle Atlantic states... and the low does not develop until it passes through 40/70..

The next important aspect to the potential for the event on January 21-22 is the strong shortwave over the Southwest. The midday European shows this feature the best.
http://www.meteo.psu.edu/~gadomski/ECMWF_12z/f72.gif

12 z Tuesday Ukmet concurs
http://www.meteo.psu.edu/~gadomski/UKHEMI_12z/f96.gif

That shortwave is going to develop a significant amount of overrunning precip over southern & central TX and given the fact that the Arctic HIGH will be fairly South the potential exists for significant snow and ice event over places such as San Antonio Dallas into the upper Delta and the the Tennessee Valley Jan 19-20.
http://www.meteo.psu.edu/~gadomski/ECMWF_12z/f196.gif
http://www.meteo.psu.edu/~gadomski/ECMWF_12z/f120.gif
http://www.meteo.psu.edu/~gadomski/ECMWF_12z/f144.gif

The midday op GFS solution as well as the gfs 12z ensembles showed a reasonable solution at this time ... with the primary Low & the secondary Low at almost equal strength with some sort precipitation passing over the Northeast but not as an impressive system.
http://www.meteo.psu.edu/~gadomski/ENSHGT_12z/f144.html
http://www.meteo.psu.edu/~gadomski/ENSPRS_12z/f144.html

However most of the medium-range models are just now focusing on the developing - NAO that is forming over southern Greenland. Again once his feature IS in place AND we have that deep low over southeastern Canada -- the 50/50 Low -- when the main shortwave energy in the subtropical jet that comes out of lower TX it wil be forced to stay to the south as will the primary Low.

If we were taken made a European verbatim we would see a significant ice storm over the Southeast states and then snow over the I-95 cities that turned over to rain because the cold High slides out to sea... while inland some places could see a significant snow. And in this sort of set up my new location up here near Leesburg VA could benefit from the that kind of set up.
Behind that feature we had yet another plunge of Arctic air into the central and eastern CONUS.
Taking a look at the hemispheric depiction of the mean 8-10 day 500 MB heights we can see that the operationally European which yesterday was showing a fierce REX block developing over Greenland-- and hence a very strong negative NAO -- is now no longer showing that feature!
http://www.meteo.psu.edu/~gadomski/ECMWF_12z/hgtcomp.html

On the other hand the operational Tuesday 12z GFS which yesterday was showing a 500 MB ridge extending NOT into Greenland but east of it into Ireland... is now showing a severe negative NAO because the model is showing strong Omega block configuration developing there as well.

The 240 hour GFS ensembles and midday are amazingly cold and show a lot of consistency.
http://www.meteo.psu.edu/~gadomski/ENSHGT_12z/f240.html

The operational run shows a strong Arctic front already moving through with the Deep trough right along the East Coast... with several members showing equally strong troughs and some of them further to the WEST -- p04 p05 p06 p07 p08 p09

lastly have to mention the appearance on the operational GFS again of a severe Arctic outbreak developing sometime around the 26 427 the January. This first Started showing up late last week on some of the operational runs but of course we all know about the GFS famous cold bias.
Again however if we look at the GFS ensembles we see some support for the severe Arctic outbreak the operational model showing at midday.

the top row furthest LEFT represents the operational run... with the following mebers supporting the idea of a major arctic outbreak occurring at this time frame or about to occur P09 p07 p06 p05 p01
http://www.meteo.psu.edu/~gadomski/ENSHGT_12z/f336.gif

more on the SE CONUS RIDGE FROM HELL?

2007-01-14T09:53:00.000-05:00

I was going to issue a final call with regard to be developing system moving through the Midwest and southern New England but after looking over the latest data and Seeing that the main event is still 24 plus hours away I'll think all hold off until early this evening.
I've noticed looking at some of the weather boards is quite of the dismay and concern and disbelief that the warm air is going to surge as far north into New York State and southern new england as the models are showing. However the problem here is not whether one wants to arse kiss the NAM/WRF or the op GFS or even the SREF for that matter.

The problem is that synoptically there is Not a lot of support for the idea of keeping the Low level cold air in place over lower New England . There is little if any Eastern neck or extension of the Arctic HIGH now over the Upper Plains on the short range models and this makes sense synoptically.

As a result even as the LOW begins to develop the Ageostrophic circulation over Lower New England there is NOT a lot of cold air to pull south. Moreover when the 850 low is tracking too far to the north NOT to erode the cold air. When your 850 Low tracks that far to the north -- N of Cleveland and over or North of BUF and BGM you are going to have real problems keeping the cold air which is only marginal to begin with in place over Low New England.
Of course the cold air does not get into the East coast until after the Low passes off the New England coast on Monday.

I'm sure that the last few runs out some of theMR odels have caused quite a bit of consternation for those who want to see when to return to the eastern US. I was going to post on its Saturday but I want to see how things were going to play out before overreacting to what appeared to be a series of significant is handling so the features on some of the MR models.

Obviously the cold air is in place across the eastern US from the 16th into the 19th. The problem is that some of the models have been taking the next piece of energy coming in on the Pacific Jet from the far northeastern Pacific / western Canada and dropping it into the western US. This causes the Southeast Ridge to re assert itself and keeps the eastern US not nearly as cold as it might be of the otherwise. http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/00/images/gfs_500_120s.gif
However there is big difference SYNOPITCALLY this time around. Over the last several weeks we have had a strong Ridge over the Southeast or just off the Southeast coast there is been no vortex over Northern were eastern Canada to counter the power of the Ridge. As result the warm air gets to run across the eastern half of the US with no check or balancing factors. This time around even IF the operational GFS is correct we do have a large vortex sitting over eastern Canada which does keep the Southeast Ridge somewhat suppressed at least allow temperatures to remain close to seasonal normals over the eastern third of the US. That its you "BUY" the last few runs of the Op GFS.

which I dont.

Most of the other Medium range models are taking this energy that's dropping into the western US and closing off a 500 low over California and then retrogrades out into the immediate Pacific off the California coast. This results in a rex block configuration.... the 500 closed cutoff Low off the s california coast and the RIDGE over Alaska. The 0z euro shwos this nicely
http://www.meteo.psu.edu/~gadomski/ECMWF_0z/f120.gif

And because you have a rex configuration here the Ridge is forced North which in turn forceds the trough over the eastern US deeper as well as a deeper PV... and drops a lot more Arctic air in the the eastern US .. and of course in this pattern there is no hint of a Southeast Ridge whatsoever.

OK... now that we have analyzed the Synoptic problem lets try and figure out which of these of these two solutions/ or possible scenarios is correct one.???

Here is the 0z GFS Jan 14 ensembles. As you can see the top row far left mao is the OP - GFS... and of course you can see that it has the Ridge over the Southeast and no close cutoff low over the Southwest. But as you can see about half the models in fact you have a 500 MB configuration that is much closer to the operational European.
http://www.meteo.psu.edu/~gadomski/ENSHGT_0z/f144.html

The latest runs out the UKMET also strongly support the operational European with the closed 500 low off the California coast and rex block setting up which drives the Ridge over Alaska actually eastward into western Canada. And we can also see us on the latest run all the0z op
http://www.meteo.psu.edu/~gadomski/UKHEMI_12z/f144.gif

OZ CMC DAY 6
http://weatheroffice.ec.gc.ca/data/model_forecast/hdd_50.gif

As we go further out in time we can see other problems develop with the operational GFS not only against the other medium range models but versus its own ensembles. Because the model screws things up at D6 and D7... the d9 and D10 solutions also model outliers and by considerable margin. Notice we can see the operational GFS here at day 10 is vastly different that what almost all the members are showing which is a huge trough over eastern US and a lot of very cold and place along with the potential for some sort significant storminess in around January 23 --24

Here's a comparison between the operational European day 8-10 500 MB mean heights on the LEFT vs the OP GFS day 8-10 on the right ... and you can see vast differences between the two. One of the reasons why the European weekly ensembles are showing such a cold blast coming into the eastern third of the US especially the Northeast in the last week of January & the first week of February is because the Ridge which is now over the Gulf Alaska is not really a +PNA configuration at all. But the development of the 500 Low off the California coast that retrogrades into the eastern Pacific and sets of the rex block results in the Ridge from the Gulf of Alaska being forced into western Canada and that DOES set up a +PNA which also finally gets rid of the Southeast Ridge once and for all.

Moreover the operational European is really developing the Ridge in the Central Atlantic Ocean and trying to drive it towards Greenland... which would be a significant development if the model is correct. The operational GFS just shows the strong Southeast Ridge now displaced a little bit into the Southwest Atlantic Ocean but it has no hint of any sort of ridging in the North Atlantic trying to drive towards Greenland Iceland.

In addition the operational GFS to showing a much weaker vortex and a much weaker northern branch....
http://www.meteo.psu.edu/~gadomski/ECMWF_0z/hgtcomp.html

As you can see the top row far left mao is the OP - GFS... and all you have to do is quickly scan through the different members to see a much deeper cloth over the eastern US.
http://www.meteo.psu.edu/~gadomski/ENSHGT_0z/f240.html

You can also compare the operational run of the GFS to the other members on this link and see that the white lines which represent the operational run are not nearly as deep as the vast majority of the GFS ensembles
http://www.meteo.psu.edu/~gadomski/ENSHGTAVGNH_0z/f240.html

Therefore based upon all that I have seen so far it's pretty clear that the operational European at D10 is running far superior to the operational GFS. It should be noted that a D10 the operational Canadian has a significant snowstorm for the East coast and European is also showing some sort system coming out of the Southwest low and thee is t least some cold air in place over the Northeast that results in a possible winter threat as well but not nearly as impressive as what the operational Canadian showing. Even in the operational GFS does eventually get out to showing a couple threats and these are showing up on both the operational 0z and 6z runs... at around 240 and 300 hrs.

JAN24 6Z
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/06/fp0_252.shtml
JAN 24 OZ OP GFS
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/00/fp0_240.shtml
6Z and 0z at 300 hrs
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/06/fp0_300.shtml
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/00/fp0_312.shtml

1ST GUESS COMING FOR JAN 14-15 EVENT

2007-01-12T12:25:00.000-05:00

-45 this morning in Yellowstone Natl park in far northwest WY this morning.
LEFT MAP is MIN temps RIGHT MAP show the MAX temps
FROM JAN 5
http://www.meteo.psu.edu/~gadomski/MAXMIN_NA/t-7.gif

FROM JAN 11
note the change in max and MIN temps over in western Canada
JAN 11 http://www.meteo.psu.edu/~gadomski/MAXMIN_NA/t0.gif

One of the characteristics of the El Niño winter is an enhanced or stronger than normal STJ- or subtropical jet. This can have a significant impact and manifests itself with forecasting problems in several different ways.

When you have a moderate or strong El Niño he subtropical jet becomes so strong that it into overpowering the PJ (polar jet) and as a result you can often get a zonal or west to east flow across the CONUS with all the Arctic air bottled up north of US Canada border. This will we saw in much of November and Decmber and when you had a four taxes situated over the Bering Sea... this sort of synoptic pattern in the general sense is more likely to be dominant and not.
Another characteristic of course it is that any sort of cold air outbreaks ends up coming in weaker than forecasted and / or does NOT lock in. I can this will we saw in the first week of December when the El Nino was moderate. This is NOT however a problem in weak El Ninos events.

Still another SEASONAL and common characteristic of Moderate El Niño winters featiures systems which are supposed to be fairly strong and take northerly tracts end up getting suppressed or shunted Eastern Northeast because of the progressive and stronger than normal subtropical jet.

Sometimes you will see in a El Niño winter where systems coming out of the Gulf of Mexico are depicted by the medium-range Models as developing into a major winter storm for the Midwest or the East Coast. Then as the possible event gets closer and closer the tracks end of shifting further to the south and east. Sometimes this can work for the benefit of those wanting snow and ice in the big cities of Northeast or Midwest. A classic case of this would be a track shown several days outgoing up the Appalachian Mountains and then as we get closer and closer to the possible event the track is shifted to the south and east so that a time event actually occurs the system is tracking through southeastern Virginia.

But on the other hand this can also work against you . When you have a very strong Arctic outbreak like we are currently experiencing and will be over the next several days the cold air plunges deep into the Plains and the eastern half the US. But without that any high latitude Blocking over eastern Canada / Greenland sometimes the cold Arctic HIGHs will drop all the way into Texas and Oklahoma and then track east across the Tennessee Valley. ( liek we are going to see over the next 4-5 days).

Because the flow is so progressive the enhanced STJ any sort of Low pressure development activity stays flat along the Gulf Coast and its tracks E or ENE tracking off the southeast coast of US... which can often result in winter weather lovers in the Midwest and Northeast nashing their teeth in frustration saying how the hell is Alabama getting more snow then Pennsylvania?

The morning weather map shows the Arctic front has driven into northern Texas and east and Oklahoma but it has NOT yet reached the Midwest b/c of the power of the the Southeast Ridge. Earlier there was some speculation that the significant shortwave coming out of the Southwest would become a Plains a snowstorm with heavy snows developing from Denver towards Minneapolis or maybe northern Wisconsin. However I argued several days ago here and in some other forums that such a forecast was bogus because of the seasonal trend one must taken consideration when you're dealing with weak and moderate El Niño winters.

In addition the model data has been very clear that the shortwave coming out of the Southwest US is going to be "suppressed " or crushed d by the strong Polar Jet dropping out of Canada. It is a GOLDEN RULE OF SYNOPTIC FORECASTNG and one that should be well-known ....when you have a s/w which is getting crushed or weakened it is very hard for the system to track to the NE or NNE. I will be issuing a FIRST GUESS for the Midwest and New England event shortly -- it's hard to believe that this point in the winter we have had so little activity in eastern half the US that this is the first one of the season I am doing here on January 12.
From what appears to me right now it looks like locations such as Des Moines Iowa Rockford or knowing at Chicago will see the best nose probably over to Detroit and then across Buffalo Syracuse perhaps Albany and then north New England. The tricky as portion of this is going to be eastern New England. No doubt that the initial precipitation over Boston will be generally rain at the start but once the 850 Low tracks closer it may shift to the south and the thermal gradient associated with this 850 Low is going to be very impressive. Additionally once the system was off the New England coast to may be some wraparound snows b/c of the comma head moisture into east New England which could produce some decent snows as the system is pulling away.

I also want to announce that I now have access to the European weekly forecasts that run out to 30 days or four weeks. These come out every Thursday evening or early Friday morning. And the latest information on these models are showing very cold temperatures the last week of January the first week of February over the entire Northeast quadrant of the country which means not only New England and Atlantic also the how Valley in eastern Great Lakes as well. That being said there is No support for the idea that Jan 15-Feb 15 are going to place in the top 10 coldest 30 days period in the last 50 years.

I am concerned that the potential exists for some sort of wave or Low pressure to develop over the Gulf/ Delta because the fairly s/w that develops a negative tils over the Mississippi Valley around January 20 --21. This is an showing up on some of the European and GFS ensembles over last few days so I think thee is enough support in ensembles that it registers as a RISK for the first POSSIBLE winter storm for the East Coast of the season. Right now it appears that the cold air is going to be around at the start but the Polar Let configurations dont look good. The lack of blocking over Northeastern Canada and Greenland is going to be a problem. You see if the Arctic high pressure systems continued to drop Deep into the Plains states then track across the TN VALLEY then off the SE coast then thigns are goping to have to occur JUST right to keep the cold air in place over the NE CONUS. We could end up seeing an event where the first cold High slides off the East Coast.... the Low develops between this high and the next Arctic HIGH that dropa out of central Canada and as result we end up going from snow to rain over the big cities of the Northeast. If we only had some high Latitude blocking to keep the cold air in place -- such as a Grenland Block OR a 50/50 Low then things would look a lot more promising and that may yet develop.

op 6z GFS shows severe Arctic Outbreak; makes my post about Stunning Pattern reveral ( last SAT) Look good!

2007-01-10T12:16:00.000-05:00

Sorry about the fact that yesterday there was no midday update but that's because there really was not a lot to change. As I stated yesterday the key to any sort of wave Low pressure development after the 15th of January along the southeast Coast is what happens to the energy hanging back over the Southwest states.

Since the midday runs ysterday-- the euro CMC ukmet and GFS -- all ended up crushing the shortwave as it tried to pull east from the southwestern states there was no reason to go into a detailed analysis. Part of what's happening is that the models are ripping apart the shortwave in the Southwest with some of the models taking a piece of it and shoving it west or another in other words and retrograding it into California and off the Southern California coast. I am not really confident that this solution is correct but that's one reasons why the system gets crush because these models are ripping apart to pieces.

Of course we are going to have to watch this very carefully as there is a window of opportunity for some sort of wave to develop warm front over the southeast JAN 16-18. But notice what most of the models ate doing here. Without any High latitude blocking the trough becomes very deep and the strong High pressure area drops or falls into the trough... tracking from western Canada along the east side of the Rockies all the way into Texas and Oklahoma. This is a very bad sign for significant snowstorm activity for the East Coast and especially the Northeast.
This is WHY the blocking pattern over Eastern Canada is SO importnat becasue it forces the arctic High pressure systems to stay to the North and track along the US Canada border.... instead of falling into the central and Lower Plains. The High to the north keeps temperatures cold over the East coast but also provides access to ocean moisture as well as being BIG player in the set up all of ageostrophic flow when East coast Low pressure development is underway.

On the other hand when you do NOT have any high latitude blocking then you have got real problems in terms of getting a good winter pattern cooking. There is a tendency among weather hobbyists to really downplay the significance of high latitude blocking ....such as a sustained negative phase of the NAO. I know that there are some out there who say while you can still get big snow oin the Northeast without a Greenland block as long as you have lots of cold air. Often times the February 1995 noreaster is cited as a classic case of a good snow for the I-95 cities that and as rain and there was no high latitude blocking.

Well that may be true but also proves the rule. You see the issue is not whether you can get a good snow in the Northeast without any high latitude blocking or negative phase of the NA O. You most certainly can BUT it won't stay all snow and that in my opinion is always the big issue. The February 95 system was such a rapid moving system that by the time the warm air got into the big cities of the Northeast most of precipitation had already fallen so we ended up with 85- 90% of the precip fell as snow and then the rest as drizzle or freezing drizzle. If the 2/1995 had noreaster move at a more typical speed OR if the Noreaster had closed off in the upper levels the High latitiude blocking would of been far more important. Tthe warm air would have had more time to drive inland into the I-95 cities.... meaning less snow and more rain.

It's imperative that when folks discuss snow storm patterns on a synoptic scale we have to make a clear distinction. If you want the event to stay all snow... then you do NEED a confluent flow over the Great Lakes and southern Canada / Northern New England... and this comes about because of the High latitude blocking over Eastern Canada and Greenland . Moreover the high latitude blocking keeps the cold high in place during the actual period of time when the precipitation is falling. Without these features in place you can get a good snow over the Big cities of the East coast but it wont stay all snow.

In this sort of pattern our you can not have a - NAO ... and in fact it when the NAO is strongly positive.. the overall best pattern you can probably get for snow events on East Coast is to have the trough access developing neutral tilt after costs as the Mississippi River or both time and reaches Appalachian Mountains. You do not want to see the trough access development negative tilt in this pattern in a matter how cold the air mass is over the Eastern have to the US. Without any high latitude blocking and negatively tilt the trough axis will force the system to track in .... and as it develops rapidly...warm air will surge into the coastal plain.

Instead what you want to see is either POSITIVELY tilted trough axis when the short wave or longwave trough reaches the Mississippi River OR one that reaches a neutral tilt by the time and reaches the Appalachians. And on top of that you want surface and 850 Low pressure areas to develop fairly far to the south latitude so that there is good overrunning and the Low pressure wave does not become too strong until it was off the coast.

I suppose the other big story has to be the operational 6z GFS this Wednesday morning showing a severe arctic outbreak developing by 324 hours ... or about Jan 22. As I stated in the last couple of blog entries the only way this sort of severe arctic outbreak happens is if we get some sort of high latitude blocking over Eastern cat or Greenland. In other words the +NAO has to switch phase and turned Nagtive. This is what the 6z GFS is doing and its reasons why the model shows the severe arctic outbreak.

Now that being the case let's talk about couple things here. The operational 6z GFS has no support from any other model nor does it even have any suport from the 0z or 6z GFS ensembles. It's possible that the 6z operational GFS might be correct BUT I would NOT bet any money on it. Of course I am sure that those who were talking about the severe cold in the January 15 -- February 15 time frame as being one of the top 10 coldest thirty day periods in many years are going to jump up-and-down about how the 6z op- GFS is likely to verify.
It may but until I see some of the model support on not going down that road and you should not either.

One last point is the 0z operational European which develops 2 hortwaves into one large system over the western US by D10 and then begins to break down the cold pattern. Of the 51 members in the European ensembles only 7 of them show any sort of similar pattern. The vast majority of the 51 member ensembles do not show a large merging of the 2 shortwaves over the western US into a close 500 low or 500 trough. Therefore I consider the operational 0z European models to be bogus.

SNOW THREAT FOR THE EAST COAST INCREASING???

2007-01-09T09:26:00.000-05:00

full update at 230 pm AFTER the 12z GFS ENSEMBLES and op Euro comes out

In case you did not get a chance to see the column or blog entry from yesterday afternoon (which was actually posted early yesterday evening) please take a look and read it carefully. That's a very important concept which needs to talk about with regard to how forecasts are supposed to change according to the data.

Let's talk about the potential for significant winter weather over East Coast after January 15. There certainly is a lot to talk about and the excitement in the various weather forums has definitely shifted from ..."well it's never going to get cold"... to "wow look at that snow threat/ pattern...".

So let's lay some ground rules here. First lets talk about the potential with this front stalling over the Tennessee Valley or the Southeastern states and some sort of wave development on the front for several days now.

The operational Run of the GFS 0z is keying on a particularly strong shortwave which at Day 7 is located over the southwest US. Because we still have a flat Ridge over the Gulf Coast and Florida... the interaction of this shortwave as its tracks east causes LOW pressure wave development and overriding precipitation across the upper Delta the Tennessee Valley into the Midlantic states and lower New England Jan 17-18. That's the general idea.
day 7
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/00/fp0_168.shtml
day 9
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/00/fp0_216.shtml
DAY 10
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/00/fp0_240.shtml

Now that being said let's talk about a couple different aspects of this. It's been said that one of the worst things is to be in the bull's-eye for the heavy precipitation or heavy snow or hurricane track at 168 hours or 120 hrs etc . While that is generally true it's missing a more important point.

As you can see from this link only 3 of the 11 GFS ensembles at 0z 216 hrs support of any sort of wave development over the Southeast in a manner which is similar to the operational 0z GFS. That should tell you that the operational GFS scenario is not likely to occur based upon the data we see at this time.
http://www.meteo.psu.edu/~gadomski/ENSPRS_0z/f216.html

However this is where the use of ensembles becomes very important and a lot of weather hobbyists weenies and even some forecasters miss this concept. If you are using the GFS ensembles from 0z Tues and say its NOT a serious threat b/c 8 of the 11 show no wave development over the Southeast... you would be correct in a technical sense. However to make such a definitive or declarative statement at 192 hrs is to be using the ensembles as a deterministic forecasting tool which is not what they are designed for.

The fundamental concept with ensembles forecasting is to use them in stochastic manner NOT a deterministic one. We have to follow the TREND in the GFS ensembles with each new 0z and 12z run .... because on the next GFS ensembles and instead of saying only 3 members showing the wave development... we might see 4 and then on the next run it might see 5 .... and on the next 6 members ... well you get the idea.

Remember the KEY feature here is the s/w in the southwest US. If there is NO s/w hanging back over the southweest states AFTER the front moves through the East coast there will be NO big winter event for the eastern US.

The second point with regard to this potential event... does the POSSIBLE winter scenario match the seasonal trend?

Well since we have been so mild for so long it's hard to say but one thing we do know is that in a weak El Niño you have a lot of activity in the Subtropical Jet ( STJ) as strong shortwave tack underneath the Western Canada Ridge and these S/W move into the southwest US. So in the overall idea or sense seeing a strong shortwave hanging back over the southwest US.... that at some point gets kicked eastward because more energy is coming in from easstern Pacific.... Well that does make sense and does match the pattern !!!

Now remember folks we are dealing with a subtropical short wave as the KEY feature we have to focus on. That means over the next several days --even on the GFS ensembles -- the GFS is going to suppress the feature because the GFS does not know how to handle strong shortwaves in the STJ. This is what we talk about when we referred to the cold bias. It over does the northern branch so strongly that the system ends up getting crushed on the Model.

Classic case of this? Take a look at the 6z OP GFS ... as you can see clearly the KEY shortwave is still in place at Day 6-7 but as you go past that point
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/06/fp0_168.shtml

-- and remember AFTER 180 HOURS is when the model resolution truncates into the much coarser model grid-- so the cold air bias of the op- GFS really kicks in and we see the southwest s/w getting crushed as it moves East. Even so we can still see some sort wave a flat one of Low pressure moving off the North Carolina coast at 228 hrs.
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/06/fp0_228.shtml

Therefore it is going to be a BIG mistake to simply to look at the operational GFS runs over the next several days... see the s/w or surface Low being crushed by the over done Polar Jet... and say "it's not going to happen...'

Just like last week when the operational GFS overdid to amounts of arctic air coming down the West Coast and over develop a PIG SE US Ridge that was supposed to develop over the Southeast and delay the arctic front arriving in the east Until Jan 17-18...

It's the same sort of GFS model problem. Only now we arew moving back to the more typical cold bias we are all use to with the OP GFS ... with southeast US Low pressure getting crushed or supressed .

CMC ensembles DO offer some support as well
CM01 CM02 CMO3 CM08 CM12 CM16
http://www.meteo.psu.edu/~gadomski/ENSCMCPRS_0z/f216.gif

The trend is MY friend

2007-01-08T22:06:00.000-05:00

sorry for the delay -- one of busiest days ever here at wxrisk that did NOT involve a Major landfall threat and or a SECS/ HECE/ MECS

The trend is my friend. It has been that way for several days and all the data continues to be going "my way". In case you did not know it by now the Australian folks have dropped the critically important ENSO 3.4 SSTAs to +0.9c which is now officially dropping this El Niño event to weak status from the moderate levels of just a few weeks ago.

I hope that you can recall the BLOG entry you from last week where I forecasted a significant drop would occur in the data .... then noted when it was released on Monday and sure enough both sites the Australians and the CPC data show a drop of -0.2 .

This is in the new piece of the puzzle as to what the second half of the winter is going to be like. As I mentioned earlier last week one of my competitors- the folks at WSI - issued a statement which was released into the media forecasting a continued mild pattern right through March across most of the Conus. That idea was based upon two fundamentally flawed on premises--- that the moderate El Niño of December would continue and the vortex over the Bering Sea will hold in place. Exactly WHY they continued to see the pattern holding when it was obvious by late December that conditions were changing I am not exactly sure. Hopefully they are seeing things ina different light.

I got a e-mail earlier today from somebody named Red Scott saying that I am out on a "limb" with my forecast for the pattern change and that I better be right about the GFS. I can understand this sort of commenti being made LAST week or this past weekend but given what the models were showing today I have to question the sanity of the person making that comment.

I may have been out on a LIMB last week but surely that is not the case now. Surely some of you can recall how the operational GFS run after run after a run ALL last week showed a Huge Ridge either over the Southeast coast of just off the Southeast coast which was going to delay the cold front arrival until at least the 17th if not the 18th of January and even then the the pattern did NOT look all that cold for the Northeast.... Midwest and Plains looked cold but not the East coast.

Really this is NOT complicated folks.

Lets say YOU are are one of those weather hobbyists or forecasters that last week argued strongly that there was no significant pattern change coming up... and that if it does get cold over the Eastern third of the CONUS by Jan 15 it was only going to last for 7-10 days... then the pattern would rebuild with the trough shifting out west the Ridge over the southeast comebacks and most of the 2nd half of the winter will feature more mild conditions.

Based upon what you have seen over the weekend and this morning the dramatic shift in the operational and GFS ensembles should be a warning sign that your "scenario" of how you think the next two weeks are going to play out is in trouble.

To be sure you could be correct. I could be wrong. There are no guarantees. But let's follow this logic carefully OK?

WHY has the last two months of this winter-- all of NOV nearly all of DEC and the first 10 days of Jan --been so warm?

You could argue it was the moderate El Niño. I sytated earlier that when the El Niño was weak we were cold and September October... when it reached moderate intensity the pattern turned mild.

You could argue it was the developmental large vortex over the Bering Sea flooded western Canada with a fairly strong Pacific Jet that prevented any sort of amplification in the northern branch of the Jet stream. Of course such a vortex in THAT location is common during moderate El Niño events.

You could argue that the Pacific Ocean -- the PDO -- was in the Negative Phase which means a lot of cold water over the eastern Pacific / West coast which supports a trough of the West Coast and therefore Ridge in the East
.
You could argue that one reason was the lack of any High latitude blocking over eastern Canada Greenland because of the very bad unfavorable sea surface temperature configurations in the Northwest Atlantic.

You could argue that since the Polar Vortex was on the other side of hemisphere ---that is to say over Asia it has been impossible to get any sort sustained cold pattern in North America since the heart of the cold air is on the other side of the world.

You could argue that is because the EPO has been a positive phase for most of November December and the first 10 days of January there cannot be any sustained Ridge on the West coast.

Pick your reason. You may pick or select several of them. I would. Some of the above stated reasons are interrelated.

SO.... If you a forecaster that is still arguing that the pattern shift is not really a big deal.... and it's just a cold weather interval... then you have a serious problem.

If your reasons for issuing a warm forecast and a continuation of the more pattern over North America to all November all the semblance first 10 days of January... how do you STILL make that forecast since almost ALL of those item / facts I listed above have changed?

A+B+C+D= forecast

The moderate El Niño? Well baby's is a dead and buried. And if you're going to argue that a weak El Niño means the same sort of overall general pattern as a moderate El Nino over N.America while I am going to have to ask you to stop forecasting because its prerry clear you don't what you talking about.
The vortex in the Bering Sea? That sucker's gone and we now have a large Ridge over Alaska.
The negative Phase of the PDO-- the cold water along the West coast of N.America and eastern Pacific --is still there but their been plenty decent Winters we've had a -PDO.

While we do not yet have a -NAO we do now have a Polar vortex appearing over North Central or northeastern Canada for the first time since October. And that is a major change.

The EPO has also switch signals dramatically as well ... from the positive phase which produces trough and along the West Coast ...into the Negative phase which generally supports Ridge and along the West coast of North America

Whatever your reasoning for forecasting the very warm pattern we have seen from November 1 of January 10 almost all of those pieces of the puzzle now changed or have moved into a dramatically different direction. This was NOT the case when the first cold blast in the first seven or eight days of December developed. The cold blast over central and eastern North America could NOT hold since... the PV was still over Asia... the El Niño still rampaging in moderate intensity.... the Bering Sea Low was still there... in other words nothing had changed. Thus you should of forecasted a short seven-day interval of cold water followed by return of the mild pattern. I did that.... as did MOST forecasters . No big deal.

BUT to still hold the same view at this time is to argue or suggest that WEATHER does not really operate on a scientific process. That things like Teleconnections and patterns and SSTA and Indicies like the EPO and NAO and PNA have no real meaning. I don't agrew but we will have to see.

I have seen some talk out there all of similarities with this upcoming cold pattern to what we've saw back in the Winter of 1977 -78. In my opinion that's just hysteria and hype mongering to the nth degree... its just a effort to get ahead of the curve through over done headlines.
There is nothing in this coming pattern that is going to be as impressively cold .... to what we saw in 1977-78. Not even remotely close . The whole idea is ludicrous. You cannot through that term around loosely like that and NOT expect to be called on it.

If we were to get blocking over Central northeastern Canada.... and we were to see a -NAO ...THEN and only then one could make the argument on the similarity in overall pattern to that infamous and severe winter. But as the data stands right now for next two or three weeks... no.

Lastly I am gratified to see that some of the posters over easternus wx who last week asserted I was going out on the limb... and misread the models.... that I was not recognizing the southeast Ridge and I was too fast and strong with a cold front ....and jumping the gun on any possible wave development after January 15 along the East Coast .... are now talking about all sorts of potential promise with this pattern. The truth is while I did mess up the December forecast I was the first one that I know of to correctly predict the collapse of the El Niño several weeks ago. And I was one of the first ones last week that was pretty gung ho about the coming pattern shift. I know a lot of my energy trading fans are very happy today and making good $$$ off of my ideas and forecast from last week. I just hope that e some of the regular readers remember what was said last week.

hhhh

the COMING STUNNING pattern flip

2007-01-06T12:53:00.000-05:00

It's sunny it's a warm and its spectacular here in early January in northern Virginia so I will make this short and sweet. The stunning turnaround which is about to take place in the overall pattern across North America is going to be historic. But by that I mean do not its intensity y but in its complete reversal of what we've seen over the last eight or nine weeks.

Let me emphasize that point for clarity one more time. I am not talking about some sort of historic severe cold per se although the cold by the end of the month might be impressive. What I am referring to when I use the phrase "historic pattern flip" is that when you compare what we have seen for most of November most of December and the first 10 or days in January... it will be amazing. To the average person this may seem somewhat confusing because when you use the hear or read term "historic pattern change" they may think of things such as Big snowstorms and severe cold. I am usiong the term in a somewhat esoteric level... since I am referring to synoptic scale. I suppose I am talking to here for meteorologists and those who have detailed understanding of weather patterns.

Clear? Probably not but at this point I am simply going to make myself as clear as I can be and if people wish to revel in their own stupidity well that is their constitutional right.

We'll start out by showing be operational 12z GFS FRIDAY -- yesterday --and the first map here is the 240 hour from midday Friday.
http://www.wxrisk.com/MODELFOLDERS/today/gfs_500_240s.gif

As you can see it shows some remarkably bad forecasting about how the pattern is going to develop. Notice the model has shows that BIG Ridge over the southeast US which of course delays the cold front even further but it also has that s/w hanging back over the Southwest. The problem is that if you take a look at the 12z fri 240 hr -- VALID JAN 15 -none of the al GFS ensembles yesterday supported such a massive Ridge over the FL and the southeast coast
http://www.wxrisk.com/MODELFOLDERS/today/f240.gif

None. And several of the members actually showed a possible SECS event.

All this continues to be problem of the op- GFS that is simply overdoing the depth of the trough and the amount of cold air that comes into the Pacific Northwest.

Another case of this is 12z 288 hr 12z GFS... which features two major short ways in very close proximity over the western US. These two short waves that develop then Phase over the SW sattes which pops a ridge over the SE sattes and the Polar Jet is forced back north ... thus the eastern Half d the US looks very Mild again.
http://www.wxrisk.com/MODELFOLDERS/today/gfs_500_288s.gif

But once more if we take a look at the GFS ensembles will see that the 288 HR OP gfs solution has absolutely no support whatsoever. I highlighted the operational GFS with the red blue Circle -- top row way over to the LEFT and you can see that none of the other ensembles show any sort solution like that and many are impressively cold and stormy.
http://www.wxrisk.com/MODELFOLDERS/today/f288.gif

We see major changes on 0z runs of the operational GFS here this Saturday morning. This next map shows the 228 hr 0z op GFS--- again valid for the same time -- Jan 15... and of course we can see that the strong Ridge over the southeast is Gone.
http://www.wxrisk.com/MODELFOLDERS/today/0zgfs_500_228s.gif

The 6z op GFSAT 336 hrs shows a very promising looking scenario setting up as the overall pattern splits into 3 branches --we can see the Ridge over the western Canada with Arctic Jet continues ... a s//w in the PJ approaching the Pacific Northwest and a s/w in the some tropical jet over Southern California and Baja.
http://www.wxrisk.com/MODELFOLDERS/today/6zgfs_500_336s.gif

Finally we can see the operational run of the 0z European which is extremely impressive in several ways. To begin with its much faster with the cold ffront as it moves through Midwest & Northeast.

The 0z op EURO which unlike the last several runs of the op GFS is strongly support by the European ensembles-- shows the cold front moving through the Northeast by the 14th and that it stalls at West East direction across the Virginia North Carolina border west over the KY TN border and it drops into the upper Delta. The model develops a several waves of Low pressure along the front including the first significant snow event for the Northeast on the 14th into the 15th and another one for the lower Plains the Tennessee Valley and Middle Atlantic on the 16th. The difference here it with the European model is that the upper level Low that ALL the models have over the southwest or Rockies at day 6-7 is forced to stay South because the European model as well most of ensembles show a very strong Arctic Ket OVER at western Canada that drops SE towards the Great Lakes.
http://www.wxrisk.com/MODELFOLDERS/today/0Z168ecmwf.gif

http://www.wxrisk.com/MODELFOLDERS/today/0z192ec.gif

http://www.wxrisk.com/MODELFOLDERS/today/0z240ec.gif

As a result the 500 low is forced eastward and cannot track towards the Great Lakes.... instead it HAS to stay further south which knocks down the Ridge over the southeast much faster and potential exists for significant what to weather for the first time all winter over the East Coast.

I suspect that when we see the midday Saturday calls the GFS the model probably flip back again and show a very deep all the last much bigger Ridge over southeast. And if the model does not do it on this front it'll do it on each PC one or some run on Sunday ... which in turn will cause more widespread weenie consternation and suicides. Not until we get within seven days how the actual event--- Jan 15-7 = Jan 8 will the operational GFS begin to carry any way with me whatsoever.

In fact do not be surprised if at some point the GFS swings all the way around to the OTHER extreme ... ocne the model sees the cold is coming east that huge Pig ridge will collapse on the model and I would not be surprised if the front is supressed all away into the Gulf Coast!!

The Ball pops Lose!!! FUMB!!!LE--- the op GFS has Fumbled the ball

2007-01-05T09:54:00.000-05:00

It's not part of my makeup to kick a weather model when it's down but in this particular case I have to do it again because of some significant things which need to be pointed out.

First... A couple days ago I mAde a post/ blog entry about the threat of a Seattle/ Portland snowstorm for January 9 -10. I made that post for two reasons one of which is not particularly honest. I made that post because I thought that there might be a chance that Seattle and Portland could see a significant snow event.... IF that wave developing on the arctic front over the eastern Pacific and Western North America dropped down far enough so those cities would be on the northern side of the surface and 850 low.

However the other reason is that I strongly suspected that the operational GFS was over developing the northern and southern streams into this huge monster trough along the West Coast. And as I've been arguing over the last couple of days not only is this West Coast trough over done by the operational GFS but it has major implications with reagrd to how fast the cold moves across the country and how strong the Ridge is going to be over southeastern states.

In other words IF the op GFS gets the January 9 --10 Northwest storm correct than the odds are very good that it is solution for the Southeast Ridge being stronger than any of the model and holding on longer than any other model data showing.... is also likely to be correct . Ya follow?

On the other hand IF the operational GFS screws up the system on January 9 and 10th .... the Low does NOT come in all along the California Oregon border but instead tracks to the north of Seattle... say over Vancouver and lower British Columbia... it means that the solution as shown by the Canadian and European ensembles means as well as the op ECMWF are probably going to be correct with regard to the handling of the Ridge over the southeastern US.

Well in case you missed it here are the links from the 0z and 6z op GFS for Jan 9-10.
0z op GFS at 102 hrs VALID JAN 9 at 6z .... note how the low pressure area is at least 300 miles north of Seattle and even passes while north of Vancouver!!! I mean Jesus H. Christ folks .... what a horrific model bust
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/00/images/gfs_slp_102l.gif

The 6z op GFS shows the same
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/06/images/gfs_slp_102l.gif

the ONLY possible conclusion that any meteorologist can draw here is that the operational GFS is suffering from its severe cold bias problem and that every other solution which is based upon the position and depth of the trough over the West Coast and the downstream monster Ridge is bogus and suspect.

If that doesn't convince you lets talk about this upcoming cold shot Jan 8-10 over ther Midwest and Northeast ....which many forecasters are missing or downplaying. Indeed I was viewing the site capitalweather.com and reading the forecast thereby Mr. Larson for the extended range around the DC metro-area. Not only did he have not the slightest god dam clue about the upcoming cold shot but it's pretty clear his entire forecast was totally based upon the operational GFS. All the autumn operational medium-range models on January for sure pretty significant cold last coming through.

Here is the January 3 OP GFS at 12z valid for Jan 9... as you can see the trough over the Northeast is very shallow and does not have a perfectly impressive amount of cold air with it at the 850 level. There is a small area of -10c over the Great Lakes and far western portions of Pennsylvania New York State with most areas of the Northeast according to the model seeing 850 Temps of -5c to -10c.
http://wwwt.emc.ncep.noaa.gov/gmb/STATS/maps/avn/graphics/2007010312avnf144.gif

24 hours later the January 3 one of the 12z OP GFS shows very rapid warning over the Midwest and Northeast.
http://wwwt.emc.ncep.noaa.gov/gmb/STATS/maps/avn/graphics/2007010312avnf168.gif

Now let's take a look at the data as from the 0z Jan 5 data -- op GFS -- here are a sample of the 850 temperatures for several selected cities over the Ohio valley and the Northeast for Jan 8 Jan 9 and Jan10

BOS.....+7C..... -11C.....-12C
ALB..... +3....... -11C..... -15C
PIT...... -8C......-10C...... -15C
NYC.....+4C..... -10C..... -12C
PHl.......+1c...... -9c....... -12c
CMH..... -9C......-9C...... -15C
DCA..... 0........ -7C...... -13C
RIC...... 0........-5C........-13C

Again the point here is that the operational GFS from from just a few days ago
clearly mishandled the upcoming strong but brief trough over the eastern half of US for January 8-10. Just like it has clearly screwed up te Pacific NW Low for Jan 9-10.

I am hoping that these two examples which are real hard factual examples of the cold bias of the operational GFS is being picked up by some folks out there but I have a feeling that's not going to be a case. Certainly reading the midday discussion yesterday from HPC they were clearly ass kissing the operational GFS like Sam Champion at a gay men's health club in New York City.

12Z thursday update; LOOK there Stands the VIRGINIAN like a stone Wall

2007-01-04T15:57:00.000-05:00

Now that the midday models have run we can take a look at the pattern change in some more detail and we continue to see the operational run of the midday DFS screwing things up after day 7 ina BIG way.

I want to be clear on this particular point. This is not simply a matter of not accepting the operational runs of the GFS because it's warm and I'm biased towards the cold or because it offers a solution that I like versus a solution that I don't like. There is serious scientific reasoning behind runs over the last several days are bogus and of little value. Of course that doesn't mean I am guaranteed to be correct.... and it certainly is possible that the operational runs of the GFS code against all probability turn out to be valid. But even if I turn out to be wrong I would still have to go in this direction in any similar situation because 9 times out of 10 a model outlier that goes against this much model consensus is always wrong.

To begin with one has to consider which of the models have over the last several weeks been for more consistent with the warm pattern and which model has been overdoing the cold along the northern portions of the US near the Canadian border. Clearly the European model has been far more correct in the operational GFS.

Second because the GFS has a truncation problem after 180 hours the operational solution in particular often ends up with goofy solutons from 192 to 384 HOURS. By model truncation I am referring to the problem that the GFS model has in its resolution which is significantly different after 180 hours. From 0 to 180 hrs the operational GFS grid points are 55 KM apart... but after 180 hrs the grid point spacing is essentially DOUBLED. Of all the global weather models which deal in the Medium & Long range forecasts ONLY the GFS model has THIS particular problem. There is a long history as to why the folks at EMC / NCEP decided to set up the GFS this way ... without going to too much detail EMC believes that running the model four times today at two different resolutions is more useful than running the model twice a day at the same resolution. Of course the folks at EMC are completely long on as but that's not to stop them from continuing to do it nor are they going to do it that their entire premise is bullshit.

Third... all of the models have a particular bias or problem or tendency and good forecasters have to keep these model biases or tendencies in mind. In this particular case the cold bias of the GFS... which is a tendency of the model to overdo the power of the northern branch of the jet stream also known as the polar jet is a well-documented problem with the operational GFS... and. To a lesser degree the GFS ensembles. It is not suddenly a problem which has appeared out of nowhere because you may not have known about it.

Again if you take a look at the operational GFS at the D10... you can see this huge Ridge over Southeast states BUT again when you compared the 12z Thursday op GFS to the other members of the 12z GFS ensembles you see major differences.

Taking look at this link of the 12z Thursday and ensembles -- the operational run of the GFS which is on the top row in the far left hand corner... notice the huge Ridge or closed contour over Georgia and Florida of 588 dm. Now go through the rest of these models and see you can find any other member but also shows a huge 588 close contour over the Southeast.

If you can find one which shows that... you're probably drunk or mentally retarded . The issue is not whether there will be a Ridge over the Southeast coastJan 14---- their most certainly will be. The issue is whether there is a huge close condor dome sitting over the Southeast US which is what the operational run of the GFS is showing.

http://www.meteo.psu.edu/~gadomski/ENSHGT_12z/f240.html

One we compare the insomnia versus the operational run
http://www.meteo.psu.edu/~gadomski/ENSHGTAVGNH_6z/f240.html

We again see that most of the RED lines on the map on the RIGHT are significantly further suppressed over the Southeast than what the Operational run is showing.

And we can see the same thing for late on January 15... the map on the left shows ensemble mean with the trough now covering MOST most of the US... while the map of the right shows the white lines ( operational 12z THURSDAY GFS heights) with a very strong enhanced Ridge over the Southeast. But again if you can see for most of the RED lines and most of the GREEN lines and most of the BLUE lines they are all further south and east and what the operational run -- WHITE lines-- are showing.

Finally let me talk about the midday European which in my opinion is very promising. The operational Thursday 12z European closes off 500 low over the Southwest which the OP Ecmwf has been doing for several runs. This is what I was talking about earlier today.... But more importantly at D9-10 the 500 low retrogrades into the eastern Pacific off the California coast and this does two VERY important things.

First having a block in the eastern Pacific MEANS that the Northern branch / Polar Jet is much stronger and comes much the with further south then the 12z op GFS or 12z GFS ensembles.. and delivers significant amounts of cold air into the central and eastern US

Second the REX block ..... becomes a storm of pump for eight feature which the look constantly ejected energy or shortwaves from the larger 500 low off the Southern California coast. These shortwaves would move east fairly quickly and interact with the frontal boundary over the lower Plains and Deep South.

This is what set the stage for several significant over running events and with always cold air in place-- at least according to the date 10 operational European... the first significant winter weather threats for much of the eastern US somewhere between January 15-20.

Its NOT Brain Surgery folks but you do have to STOP using the Op GFS runs

2007-01-04T09:33:00.000-05:00

Its not brain surgery ...

but before I start this morning let me introduce a NEW and New model link as well . First the model link from the fabulous Penn State E. Wall site... a whole new page on the ensembles products from the 0z 6z 12z and 18z GFS ensembles as well as the Canadian. I will be using some of these in a few minutes.

The introduce a new terminology here in the weather business.... a term that is used to describe a particularly offensive and aggravating type of weather hobbyist or weather WEENIE .... PCW... which stands for Pathetic Crybaby Weenie. I suppose it's understandable that given the amount of access there is to all sorts of weather model information out there on Internet and how mild and the uneventful the winter has been for much of the CONUS east of the Mississippi River... that they would be a lot of anxious weather hobbyist and weenies out there who are looking forward to any sort of sign that the pattern might be changing into something closer to normal for mid-January.

However when you are dealing with the PCW... none of that actually matters. A PCW wants to see their snow right away this second God dam it and if he does not have HIS snow then obviously it's the end of the world. The PCW is simply unable to grasp any sort of reality and time has no sense or meaning. Thus if you forecast the pattern to change January 15 and its January 4 and the pattern as NOT changed then clearly the pattern change is not coming and the winter's total bust.

In addition the PCW is not really interested in the science of Meteorology but only in the perpetual chase of the BIG or historic snowstorm. One of the ways that you can detect a PCW as opposed to regular weenie is that PCW often makes a post with a really idiotic or ostentatious sounding alias or handle... in order to impress other people that they know what the hell are talking about. For example they may have a handle and make weather posts under the name of say superstorm Andrew or blizzard of1888 when really they probably should be posting under the name DORKWAD 2007. What is even more offensive about the PCW's is that they are growing at a exponential rate on therse weather Boards and the refusal of some of moderators at the various weatherboards to intervene is really causing quite a bit of anxiety and consternation --judging from my e-mail -- among professional forecasters as to whether or not they should be interacting with the general public and especially the weather weennie community.

OK let's get to the synoptic meteorology. For the life of me I cannot figure out what was causing all the anxiety in consternation yesterday afternoon on the various weatherboards for the anticipated pattern change. I see absolutely no reason the back off the idea that the cold air is going to return to the eastern US in and around January 15. That being said let me emphasized that January 15 is NOT the same thing is January 4 and is not the same thing is January 10 . This point is so obvious it's hard to believe that it needs to be stated but apparently after reading the various weatherboards... it's obvious that it has to be. If it is supposed to be warm from say January 10 to the 14 and it is warm... that is NOT a forecast bust.

Oh I suppose that IF one were to give any consideration to the last several runs of the operational GFS one could find some reason to be pessimistic but only a imbecile would do such a thing. It's very clear and very obvious with the operational runs of the GFS have been doing over the last SEVERAL days. The operational GFS model is driving far two much energy down the West Coast of Canada into the US and is PHASING the two streams into a deep long wave trough. The model is doing this because the classical INFMAOUS COLD AIR BAIS that many of us know about with regard to the operational GFS.

I made this a critical point in my Winter forecast ----that during these months of the moderate El Niño we would see the GFS constantly over develop West Coast troughs by over phasing the two streams and making large long wave trough on the West Coast which in turn develop a very strong Ridge over the southeast US. And sure enough that is is exactly what we have been seeing over the last several days/ runs.

BUT since many folks over the eastern US are not familiar with the GFS cold bias when it shows up on the West Coast it seems that a lot of folks and even some forecasters have forgotten the OP GFS cold bias. Yes over the Eastern US the op GFS suppress storms off the southeast coast in the cold season because it has two much northern stream action and not enough energy in southern stream. Everybody's is familar with THAT concept. However on the West Coast the same problem exists but since over the last several years all we have seen is a perpetual RIDGE over the West Coast very few forecasters and hobbyists are familiar with the cold bias when it does show up on the WEST coast.

In fact winter weather lovers actually should've been encouraged by yesterdas model runs. I know I certainly was and I still am. To be sure there are a lot of uncertainties involved in extended a long-range forecast for the middle and end of January. But one of the things that I saw in the pattern yesterday and I still see today is the development of a closed cut off 500 Low over the West Coast that in fact retrogrades off the central or Southern California coast at day 9-10 -11. As a general rule a close 500 blow over the southwest US does support a flat Ridge over the southeast or just off the southeast coast and while this can make for a cold pattern and potentially stormy 18 does significantly reduces the chance of seeing a severe Arctic outbreak over the central eastern US. There been many instances on short wave energy coming out of this 500 low and developing into significant winter storms again for the eastern half of the conus but in terms of Arctic outbreaks you don't get a big one if you have a large 500 low over the southwest US.

However if the closed cut off 500 Low over the West Coast does in fact retrogrades off the California coast then we end up with a fundamentally different pattern altogether across North America. Such a Retrogression would in fact set up a Omega or Rex Block... with the cutoff 5h Low over the eastern Pacific... and the Ridge over Alaska.

If that were to happen -- and this is a BIIIIIIIG IF -- you end with an extremely favorable pattern for winter weather over all the eastern US because the 500 low in this El Niño pattern would eject several strong short ways into Southern California and the southwest....in the southern stream that would move across the US and a pretty good clip.... while the Northern branch would be free to drop down across western Canada and to the Upper Plains into New England. It would not be a Bitter cold as pattern but it certainly does offer the potential for significant waves of Low pressure developing on stalled Front over the lower Plains and Deep South as over running events into the cold air across the Midwest and Northeast. Again this is all speculation to occur after January 15 because we simply do not know as to whether or not we are going to see a REX block.

Already by Day 7 we can see major differences developing over the eastern US with when you compare the operational 0z European to the operational 0z GFS... as you can see the European has significant lower Heights over the Great Lakes and New England where as the GFS is just blow torching everybody. In addition the western US trough over the GFS is far deeper than it is over the European. But the Op GFS gets worse...
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/00/images/gfs_500_168s.gif
http://grib2.wxcaster.com/wxcaster4/NORTH-AMERICA_ECMWF_500_GPH_168HR.gif

By Day 12 for example if we were to look at JUST the operational run of the GFS --and again I cannot figure out from life to me WHY any forecaster with any professional skill would do such a stupid thing... we can see the model of showing a huge trough over the southwest US and a gargantuan monster Ridge over the southeast and at Northern Gulf Coast area. This solution on the face of it is ludicrous and all you have to do is use any of the numerous ensembles upon which are out there to see how badly flawed the operational GFS is in this solution. I am using the 288 hour time frame here as an example but one could use the operational GFS and various time frames and come up with the same sort of proof.
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/00/images/gfs_500_288s.gif

Now compare that solution of the operational 0z GFS (which argues that the Ridge over the southeast is so fooking Huge that it is going to stay warm until July) ... to the ensemble mean which is the map on the LEFT SIDE -and you can see right away the huge vast differences between the two.
http://www.meteo.psu.edu/~gadomski/ENSHGTAVGNH_0z/f288.html

Again I have to emphasize that any forecaster out with even minimal skill can see that the operational GFS is again in the model outlier from ALL the other data and not just within the GFS per se but within the Canadian ensembles and the European ensembles as well.

If you take a look on a map on the RIGHT hand side again the white lines refer to the operational run. The white line that is closest to the equator is the operational run 576 dm line... the Middle white line is 552 dm line... the 2 white lines closest to the Arctic region are the 528 and 486 dm lines respectively.

Now take a look at the red lines... The RED lines are the various ensemble members of the 576 dm height line . Compare those RED lines to the southernmost white line which is again the operational run showing the 576 dm Height line. Notice how all the ensembles members show a much flatter weaker Ridge when compared to the white line. Then if you take a look at the middle white line... which is the operational run depicting the 552 dm height lines and compared to all the green lines you will see again that most of the Green lines are significantly further south and east and what the operational run at 0z is showing.
This can be seen even better by taking a look at the actual ensemble members themselves at this link. http://www.meteo.psu.edu/~gadomski/ENSHGTNH_0z/f288.html

Again the top map on the upper left corner is the operational running you can see the huge monster rage it has over the southeast. As you can see there's absolutely no support of any type for the operational GFS at 288 hours. All other model runs of the GFS ensembles show the cold air has driven into the eastern US or is about to. There are a few of the members that still show a weak Ridge well off the southeast coast that is rapidly leaving and there is no indication of support of any sort of monster 588 dm PIG ridge over the se and Gulf coast.
None... really this is NOT brain surgery folks but it does require some commonsense and the use of all the ensembles to figure out what the most likely solution is going to be.

This last link will show you the 288 hour hemispheric display with all the members of showing positive and negative height anomalies. Again on the top row upper left map is the operational run and you can see the huge area of bright red which shows a very strong positive high anomaly or in other words a RIDGE -- over the southeast... but again that none of the other members show any sort of huge anomaly like that parked over the southeast on January 15.
http://www.meteo.psu.edu/~gadomski/ENSHGT_0z/f288.html

Unfortunately I cannot show you the European ensembles but they are cold. The operational run has the cold ffront driving into the Deep South January 13-14 with 850 temps at
-12c over PHL to DTW and New England is even colder. Unlke the operational GFS the operational European is deeply embedded within the ensembles mean so the model is NOT an outlier. In addition I can tell you that the ensembles mean of the European model is showing a significant ice storm for middle Atlantic and New England as it develops a wave on the stalled font over the Tennessee Valley... with a large 1030 + MB High over the eastern Great Lakes JAN 14-15... however because the upper-level heights are too high it does not appear to be a snow event but the potential is there for a significant ice storm because of the low-level cold air.

Least but also First the QBO dropepd DRAMATICALLY in DEC to well under +10 to a value of +6.10... this combined with a weakening El Nino tells me the 2nd of the winter will be impressively cold and stormy for much of the US as it has been warm and dry. The comination of weakening moderate El Nino and near neutral QBO winters are a LOCK -- as much as one can have such thing in seasonal forecasting for a Good if not GREAT 2nd half of winter and a delayed spring

Editted for 12z EURO & GFS ensembles BLIZZARDS & ARCTIC COLD HEADED FOR SEATTLE PORTLAND & PAC NW?

2007-01-02T11:34:00.000-05:00

OLD MAN WINTER IS SINGING UP A STORM...

I'm a runaway train on broken track
I'm a ticker on a bomb, you can't turn back
This time... That's right...
I got away with it all and I'm still alive
Let the end of the world come tumbling down
I'll be the last man standing on the ground
As long as COLD blood runs through my veins
I'm still alive...

Over the weekend in case you missed the official reading for ENSO 3.4 SSTA came out from CPC and it showed Enso 3.4 SSTA holding at +1.2. This would indicate that the ENSO has stabilized at the low end of the moderate intensity... correct? Well not so fast Mr Naso!!!

First the data period that CPC uses end 12/27. Here is a link from the Aussie folks that they use to monitor ENSO El Niño and as you can see their data period ends as of 12/30... nd they had a much lower reading all of +1.06!!!
http://www.bom.gov.au/climate/enso/indices.shtml

Now at this point you could argue which one is correct since these are significantly different readings. However after giving it a little consideration it should be clear to all that the Australians are correct and that CPC is once again behind the eight ball. CPC was playing catch up in declaring the La Nina last winter dead in the Spring and they were behind the eight ball in declaring the current El Niño was now in effect. In addition keep in mind that the Australians of course have that later cut off time for their analysis and that over the last 12 to 16 weeks every time the Australians of come up with a different reading ....whether it was when the El Niño was warming or cooling ( as it is now) CPC has always a followed week or two later. And lastly let me point out that the low-level easterly winds are increasing across equatorial Pacific and that is helping to bring about the demise of the El Niño. These winds the first start appearing in Mid in December and the new data here on January 2 shows these winds are actually increasing.

I do not want to focus completely on the El Niño as being the sole cause of the exceptionally mild winter most of North America has seen. There are other causes for example be very strong positive values QBO... along with a pool of very warm water off the Southeast coast of Canada which is been there since Midsummer... as well as a negative phase of the PDO. As you can see there are a lot of things wrong with the overall pattern if you like cold and or snowy conditions over the central and eastern portions of the CONUS... and because there are so many things wrong it's also going to take a lot of time to get the pattern to into a more typical winter pattern.
Therefore it is imperative that you do not RUSH things and we sit back and see how it develops. Besides the El Niño weakening we also have the QBO falling below +10 ( we will know for certain the actual QBO values by the end of this week) and the large pool of extremely warm water which is been located off the Southeast coast of Canada has now almost completely dissipated.

There's also some dispute as to whether or not what is coming IS a pattern change or something else. Quite frankly I cannot see how anyone could argue that this is not pattern change. I think such argument is borderline delusional. Here are the current 850 temperatures over North America as of 1am JAN2. http://weather.unisys.com/gfsx/init/gfsx_850_init.html

Now here are the 850 MB Tt 10 days later.
http://weather.unisys.com/gfsx/10d/gfsx_850_10d.html

How any meteorologist can look at this can see no pattern change is well shocking. It seems that the entire premise that there is no pattern change coming for the eastern third US is based on the idea that it has been very mild over the past 6-7 weeks... ( correct) it is now mild ( again corect) and Jan 10 it will still be mild... ( OK) ergo no pattern change.

This sort of focus on my own back yard attitude in meteorology is really quite unprofessional. The fact that it is warm Now over YOUR or my location is NOT the defining criteria as to whether the pattern has changed. Just because a snowstorm missied your house and you did NOT get 12" of snow in your backyard does not mean that the snowstorm was not a significant event. Likewise just because your location may see several more mild /warm days does not mean that the pattern has not changed.

The first strong cold front that comes the Midwest and Northeast January 7-is only gping to last 1-2 days but it is going to be the first significant cold front in several week. Most of the model data shows that in place of the deep vortex over the Bering Sea and Alaska we are going to see a massive Ridge form which will establish a very strong cross polar flow from the arctic regions into much of Western in southwestern Canada. This is why the arctic air builds a very rapidly with even the normally conservative European model showing 850 temperatures as low as -30c and the surface arctic High-pressure system that develops in western Canada reaching a strong as 1060 mb.
Not a pattern change?

The Bititer cold will initially is going to plunge down western Canada and into the Pacific Northwest's as well as the Upper Plains and central Canada. The dispute is how fast does the cold reach the Mississippi River and the East Coast??? SCENARIO A: a deep trough forms over the West Coast which would send very cold air into Los Angeles BUT cause a strong Ridge to form over the Southeast CONUS and this delay cold air crossing the Mississippi river until Jan 16
SCENARIO B : A broad shallow trough U SHAPED troughh forms over SW Canada and the Pacific Northwest which will allow for a Flatter Ridge over the Southeast and therefore the cold air would arrives over the Midwest and the Northeast much faster. By the end of this week we should have a pretty good idea which of these two possible scenarios is going to be correct.

Over the past eekend many of the GFS model runs especially the operational runs were OVER er developing this trough by over doing the shortwave that drops in the Pacific Northwest... which results in a huge broad trough over the West Coast which would drive the Arctic cold air all into central California the great Basin and the Rokcies and place the arctic boundary over the western Upper Plains. In response to that the operational GFS models over the weekend also over developed a HUGE Ridge either over the Southeast coast of just off the Southeast coasts.... with some of the model showing a massive PIG 592 dm Ridge.
It should obvious from the get go that these two features are connected-- a huge deep trough of the West Coast means a huge strong Ridge off the Southeast coast but apparently from reading some of the weatherboards this sort of basic synoptic meteorology and logic escaped a lot of folks. oh well .
Fortunately most of the GFS ensembles do not develop a large deep trough that reaches into central California in the week 2 nor does the operational European or the European ensembles. Instead they show a broad U-shaped trough which means that much flatter Ridge over the Southeast and has implications for the whether in the Northeast by the middle portions of the month.
By 300 hrs the op GFS shows the deep trough over the West coast with Seattler & portland getting hammered... but most of the ensembles are MUCH faster with the trough progression.
http://www.meteo.psu.edu/~gadomski/ENSHGT_0z/f300.gif
Take Vebatim the last few runs of the op GFS means that one would have to forecast the RISK of seeing SEVERAL major snowstorms ( major snowstorm is relative to what those areas typically see when it does snow there!!!) over the 2nd and 3rd week of January for the Portland and Seattle.
Once that huge arctic HIGH begins to drop southward into southwestern Canada pieces of this High of going to break off in the confluent flow along the US Canada border moving through the Great Lakes into northern New England. These Baby HIGHs -- 1040 MB or so -- will be able to drive a backdoor front across the Northeast AFTER Jan 10-12... provided that the Ridge over the Southeast US is not very strong. This is why the ensembles ideas and the pattern shown by the European is much more significant because they're showing a flatter Ridge over the Southeast coast which in turn means that the baby Highs moving across the Great Lakes and North new Engand will get a chance to drive significantly cold air into the Northeast.
=========================================

The 12z OP GFS after 180 hours is seriously flawed and well just dam silly. Let look at the pattern up to 180 hrs.... BEFORE the model TRUNCATES... that is before the RESOLUTION shifts to a MUCH more coarse grid...

note that the 1st Low on the arctic front has moved into the Pacific NW at day 7 and 7.5 and can bee seen at the surface over ID and western MT.... but there is ANOTHER powerful s/w ...according to the Model Off the Alaskan Panhandle coast-- see the big RED blob on the 500 MB prog.

DAY 7
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/fp0_168.shtml
DAY 7.5
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/fp0_180.shtml

BUT BY 216 hours when the op GFS model resolution collapses .... the much more coarse and less refined op GFS screws up and drops that BIG RED blob due south into the west coast which in tuns carves out a HUGE trough and a closed 500 low over the West coast.
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/fp0_216.shtml

Once that trough is there... the GFS builds it as it tries to phase the energy coming in over the Alaskan Ridge .... so the trough expands and the Ridge over the SE coast builds.

Bullshit.

The 12z GFS ensembles all show the tuesday op 12z GFS to full of crap...
First.... at 180 hr ALL of the ensembles members show the trough over the NE CONUS is deeper than what the operational 12z GFS shows
http://www.meteo.psu.edu/~gadomski/ENSHGT_12z/f180.html

By day 10--- well forget about it... the 12z OP GFS is fooking clueless as to how to handle the pattern change... ONLY one other member (p007) supports the 12z GFS with a deep trough over the Pac NW and western Canada-- the other 10 members show the trough progressing nicely
http://www.meteo.psu.edu/~gadomski/ENSHGT_12z/f240.html

by 288 hrs it is even worse with the 12z op GFS only having 1 member showing a Big 500 low over the Pacific NW. !!!! This should tell you the 12z op GFS after day 7 is crap

The 12z EURO is also faster with the cold air pushing east and is very much NOT like the 12z op GFS.... More importantly the op Euro shwo the Big low over Greenland -- the positive NAO sliding east into the Northeast and NEUTRAL heights developing over eastern Canada!!!!
http://www.wxrisk.com/MODELFOLDERS/today/test9.jpg

http://www.wxrisk.com/MODELFOLDERS/today/test9.jpg

GIVE IT TIME FOLKS

2006-12-31T15:09:00.000-05:00

Happy New Year ya sick twisted freaks!!!

While the model data continues to increase that there's going to be some sort of pattern change after January 10 please keep in mind that we are still a looooooooong way from January 10 and this is going to be veeeeery slow process. I think the models from a few days ago which were hinting at the cold getting back into the eastern third of the CONUS by January 10 -- or even before that- were probably too fast. There are an awful lot of things which HAVE to change in the pattern across Northern Hemisphere and it going take a long time before things are finally set up in a more favorable position for those wishing colder temperatures.

The point is you've got to give this time and even as pattern begins to change into something -- exactly what that "something" is we dont know yet-- there are going to be other problems.
This first map shows you the overall atmosphere of pattern dated 12/23 and it can see their several very prominent features.
http://wxrisk.com/MODELFOLDERS/today/t-23.gif

You can clearly see the strong for Texas centered or far west Alaska or the Bering Sea and you can clearly see that the NAO is strongly positive and that there is no vortex of any type over the Western Hemisphere.

This next map dated 12/29 does not show a lot of changes occurring. So again I have to emphasize that people slow down with the pattern change. http://wxrisk.com/MODELFOLDERS/today/t0.gif

In a medium-range there is a another important shortwave which is going to drop into Southwest at the end of THIS week and bring significant rain to eastern Texas the Delta the Deep South the Tennessee Valley Southeastern states and the mid-Atlantic region. As this shortwave move off the coast it will begin to cause heights to rise a little bit over the far Northwest Atlantic.

But then the weather models drop another important shortwave into the West Coast and Great Basin. This feature brings about heavy snow to the Mountains of California and the Great Basin but it does not look like it's going to be a major snow event for Colorado this time. Instead the models show his system dropping into southern Arizona and New Mexico early next week.

At the same time will are seeing SOME signs early next week of a Height rise developing over the eastern Pacific as the vortex over the Bering Sea begins to either breakdown or retrograde back into eastern Siberia. I emphasize this point in the last update and do so again today. It really doesn't make a difference where that vortex moves. You see in its current position the Bering sea vortex TELECONNECTS to a strong large flat Ridge over the central portion of the Northern Pacific. Thus the Pacifc Jet is "squeezed: between the flat Ridge to South and the vortex over the Bering Sea.... and is able to obtain very high velocities as it slams into the Western portions of North America. And it is these very strong winds speeds or velocities at 200 and 300 MB that insures No west coast Ridge amplification as well as floods the CONUS with mild Pacific air.

So if the vortex over the Bering Sea where to shift to the into Eastern Siberia this in turn would pull the mean trough position from the Rockies back to off the West Coast and would favor a Ridge to develop over the Western portions of North America. Likewise if the vortex over the Bering Sea were to slide EAST into the Gulf of Alaska... this would bring back a pattern much like we saw in September and October. A large pool of very cold air would develop over Western Canada which does not exist now.

To get back to the synoptic points about next week... I think what happens to this new s/w over the SW sattes will be critical as to how the pattern change is going to develop over central and eastern North America. Once the shortwave over the West Coast swings into Northern old Mexico and southwestern TX... some of the models take the system up to the Midwest which of course brings a notice fairly strong Ridge over to the Southeastern states and keeps East Coast mild almost until the middle portion of the month. However the midday Sunday GFS keeps this system suppressed to the South with heavy rain or Southeast and a possible winter storm for the Midlantic states JAN 9-10... and once that feature passes through the East coast we end up with a full-blown +PNA pattern with a new strong PV over Hudson's bay and winter back under way at full power.

Of course this is just one possible scenario. I think until we get an idea of what and how the vortex over the Bering Sea gives way ir to shifts or fills or dies... we will have a lot of MR and LR forecast uncertainty. The MR and LR models really need to show some consistency in handling this feature and until they do any solution offerred for the secnd week of Jan is just speculation. For examole it is s possible we may see the weather models --especially the GFS --show more energy crashing into the Southwest which means more Ridging over the Southeast states and some model runs over the next several days may not look all that promising for those looking for colder temperatures. That's why I said in the last update that the crucial period i going to be January 3 --7 and I see no reason to change that.

WINTER GETTING TIRED OF BEING A DOORMAT OVER THE EASTERN US?

2006-12-29T10:14:00.000-05:00

I got a email yesterday asking me about the possible pattern change and that everyone else was talking about it and how come I wasnt? I can only conclude that the person sending me that eamil is one stupid bastard b/c I have been arguing for a colder 2nd half of the winter for several weeks never mind my winter forecast. That is what the talk about the weakening El Nino has been all about.

Some of you may have come across a News wire story (especially in the energy markets ) that one of my competitors in New England continue to forecast a mild winter for the second half right into March of 2007. That forecast came from WSI yesterday and was carried in the News wire services. In reading this story and trying to assess the forecast reasoning it appeared at the Lead forecaster asserted the El Nino was STILL moderate and was going to continue without any weakening right to March 2007. Well I can only assert my counterclaim that that's reasoning is bogus and this strongly indicates to me that they simply don't know how to read the data from the current El Niño. Nobody with any sort of forecast sjkill could possibly assert that the current event is as strong as was just the 3 weeks ago and that it's not going to continue to weaken.

However as I've been pointing out now for three or four weeks the evidence is pretty strong that the El Niño is weakening. And this would argue for a significantly colder pattern developing in the second half the winter.

I've also seen some talk that the weakening El Niño is going to have a significant lag effect and that there is little chance of the weakening El Niño will have an impact on the weather patterns over l North America before March. Again the meteorologists that will have been making that argument really don't know what the talking about. While there is a lag time when they El Niño or La Nina is ramping up because the El Nino / La Nina has to reach a certain threshold before they can significantly impact the overall northern hemisphere patterns.... once in the event is underway the atmosphere is a lot more sensitive and reacts a lot faster to changes in the El Niño/ La Nina so the idea that there is still large lag time of several weeks even though the El Niño or La Nina is already underway.... is simply not correct.

All of the weather models continue to show that pattern change is going to get underway around January 6 or 7. The pattern begins to shift because the Bering Sea vortex -- that's between eastern Siberia and Western Alaska --is going to shift or breakdown. The position of this feature over the Bering Sea is a common position when you have a moderate or strong El Niño. This results in the strong Pacific jet slamming into the western Canada and prevents any sort of Ridging over western Canada. Thus mild Pacific air overruns the much of North America... which has been the case over the last six weeks... and all cold air is bottled up in central and northern Canada. In addition the other feature that we've been lacking has been the position of the Polar Vortex (PV) which has been located over the Asian side of the world in the last six weeks. The position of the PV is critical in determining where the coldest air masses are likely to go and has a major impact upon storm tracks and development.

The European Canadian and American models this morning especially after Day10 shows a increasingly strong Ridge developing over western Canada and colder air finally moving into much of the central and eastern US. The data does not show severe or extreme cold by any stretch imagination but certainly seasonal cold which is pretty impressive considering how warm it's been. If you recall we had pattern amplification which occurred in the first week of December but that cold shot did not last because the fundamentals of the pattern did not shifted /change. The vortex was STILL located over the Bering Sea and the PV was still located over the Asian side of the world. This told forecasters that the cold shot in the first week of December was not going to last.

WHAT CAN GO WRONG

The THREE dominating features the pattern over the last six weeks has been the appearance of a strong vortex or large upper low situated over the Bering Sea which is between Alaskan and Siberia. This Vortex results in a positive phase of EPO. When the EPO is in that position it results in the Pacific Jet crashing into western Canada and the Western CONUS which results in mild Pacific air overrunning the country and the arctic air getting bottled up in central and northern Canada. This is well we saw in January 2006 when the nation saw record warmth.

I have seen some talk of the flat ridge over the central North Pacific being a key feature as well.. This is really just spliting hairs... the Teleconnection of the Bering Sea Vortex IS the flat ridge in the cntral North Pacific.

SECOND...the lack of any sort of high latitude blocking over eastern Canada Greenland.. known as the +NAO effect. This has allowed the Polar Jet to continue to North of the Great Lakes so again the very cold air stays well north of the Canada border. In addition a + NAO means that the "mean trough position" ( or storm track) is for more likely to be located over the Plains & Midwest and indeed that has been the case over the last six weeks. The THIRD feature to talk about is the main Polar vortex which is a huge area of very low pressure in the Jet stream ( called the AO or arctic oscillation). The position and location of the AO is responsible for bringing about the coldest air masses and when it is not a located in the Western Hemisphere Aiken often bring about a very mild winter. The AO over the past six weeks has been located over in Eurasia or on the other side of the world ( called a +AO) and hence that's where the coldest air masses have been. Over the last several winters the AO for the most part has been either neutral and / or Negative and the winters over the Eastern US have been active and stormy.

Overnight almost ALL of the extended range weather models -- OP Ecwmf to D16... The Ecwmf ensembles to D16... the 0z CMC to D16 the CMC ensembles to D16 all show significant changes. Interestingly some of the GFS ensembles are not as aggressive with the change to a colder pattern and the ridging development of the West Coast as what they were yesterday. On the other hand the European ensembles are very aggressive with the cold pattern and after 300 hours really begin to go to town in the amplification of a significant Ridge developing over western portions of North America.

Even so we're still a long way off and while the model consistency is beginning to become significant and impressive nothing stone happen until January 6-7 and it may not reach the Eastern US until the 10th or 12th.

There's a lot of data that shows significant warming occurring at the very high latitudes. It has argued (because the research has shown) that such warming is indictative of the Arctic Oscillation beginning to switch back towards North America. But I am NOT a big fan of th AO-- I think its the most over rated thing since T.O. or Hillary Clintion. It must be kept in mind that last year the AO was negative -- or over North America --but all the cold air stayed over Asia and Europe. Still it IS good to see the AO dhift back to the this side of the wordl ..IF indeed that is the case but it is not by any means a sure thing.

Next... the models are very strong in showing that the vortex located over the Bering Sea is going to shift position. It really does not make a difference which direction the vortex moves... if the feature shifts back into eastern Siberia will that's very good news for the development of cold air and a colder pattern over the eastern half the US. On the other hand if the vortex slides to the east into the Gulf of Alaska... that too is also very good news for the development of a significantly colder pattern. The point is as long as the vortex stays over the Bering Sea which is a classic position for a moderate or strong El Niño the pattern over N the orth America remains very warm as the jet stream will be coming into western Canada too strong to buckle or develop any sort of Ridging... and too strong to allow anything except for a +NAO .

The data does not show severe or extreme cold by any stretch imagination by Mid January but certainly seasonal cold which is pretty impressive considering how warm it's been. If you recall we had a pattern amplification which occurred in the first week of December but that cold shot did not last because the fundamentals of the pattern did not shifted /change. The vortex was STILL located over the Bering Sea and the PV was still located over the Asian side of the world. This told forecasters that the cold shot in the first week of December was not going to last.

If the overnight weather models are correct what we looking at is a fundamental shift in the overall pattern since the vortex over the Bering Sea appears to breakdown or slide back into central Siberia and the PV that has been over Eurasia makes an appearance over the Western Hemisphere. While I expect a lot of model variance and flip flopping the KEY point will be Jan 3-7... by then we should know IF and when the vortex over the Bering Sea is going to slide or die. If the Bering Sea Vortex does not the winter may be over .

The bottom line is that there are increasing indications that Winter is coming back but for how long and how in strong of course is still the big question.

ENSO region 3.4 droppng steadily now; is It too late?

2006-12-26T16:14:00.000-05:00

As winter weather lovers from the Rockies to the East Coast... as an into traders and ski resort operators and winter clothes manufacturers continued to bemoaned and cry over the warm December 2006 it would be easy to infer or extrapolate that the rest of the winter is going to end up just as mild and just as uneventful. However I'm not yet ready to go that route for what I believe to be a number of good reasons.

In the synoptic situation we having other strong large Plains closed cut off Low
(CCULL) that is going to develop over the Rockies and probably bring another extremely heavy snowstorm places such as Denver and much of Eastern Colorado and Western Nebraska in a manner very similar to what they saw last week. I think it is pretty the amazing how the pattern is repeating itself when you come to think about. I am not prepared to say that places such as Denver in Eastern Colorado will see 24 more inches of snow but certainly potential is there for another major snowstorm if not outright blizzard. This time it looks like a places as far west as Salt Lake City could see significance snows that could extend into much of Wyoming.
With the large high over the East Coast moving out to sea and the subtly inflow providing a abundant amount of moisture and rainfall with the cold front associated from this Plains low should produce significant showers and thunderstorms and heavy rain across the Delta slows much of the Midwest and East Coast areas by the time the month comes to end.

Interestingly the operational 0z and 12z European and even the GFS here at midday are developing a+ PNA pattern for the first time in several weeks. Of course the +PNA is not going to last in this overall atmospheric configuration but Eaton might be the sign of things to come since it is the first one were going to sea in a long time.

In case you did not notice the official readings came out on Monday Christmas Day for the SSTA's in the ENSO region 3.4... and it was down again for the second week in a row. It droped from +1.3C DEC 18 to +1.2 DEC 25.... and the Australian folks have the reading as low as +1.1
There is little doubt now in anybody's mind who has the slightest bit of meteorological skill that the El Niño has reached its peak and is beginning to weaken at a fairly good clip. If the Australian that is correct that about time we reached the first week of January we may be below the moderate El Nino threshold criteria of +1.0c.

The argument on why a weakening El Nino MEANS something is that when the weak El Nino was underway in SEPT & OCT .. THAT is when the pattern was locked in with cold and we saw several major east coast lows-- Noreasters. Then as the moderate El Nino bole above +1.0 in early NOV the cold pattern collapsed and across North America the Pac Jet took over with mild Pacific air masses taking over. So presumably as the current Moderate but weakening El Nino drops to +1.0 c and lower the CURRENT warm pattern will end as well. I don't think to many forecasters are going to have problems suggesting that the very mild and wet pattern we seen over much over the US is going to change as the El Niño weekends and drops below that magic threshold criteria of +1.0 but that is still a long way from a sustained cold and stormy pattern likely saw in September and October.

In other words is quite possible that we may shift from this current mild and wet pattern to something else but that something else is not necessarily a strong & locked in WINTER pattern for the second half the winter. So yes I do see a significant change coming in the overall pattern but whether or not it turns towards the pattern which supports the second half of wnter idea as I have described in my WINTER forecast is a totally unknown and different question.

Let me present to you some more pieces of data. This first one is the spread of the different ENSO climate models which you can see on a monthly basis at the Institute for research international or IRI wb site. Now if you take a look official notice how significantly downward the trend is in SSTAs in all the models as we go into the second half the winter.

http://iri.columbia.edu/climate/ENSO/currentinfo/SST_table.html

Compare that to the IRI NOV 2006 models .... here...
http://iri.columbia.edu/climate/ENSO/currentinfo/archive/200611/SST_table.html

If you cannot see the significant change in how the models are handling the El Niño into the second half of the winter and into the spring and you're probably blind. Or perhaps you are a ignoramous.

The CPC enso plumes that are run weekly can be seen here...
http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/images/nino34SSTMon.gif

and as you can see the data is very clear that the ENSO was on the verge of collapse at least according to these computer models and the spaghetti plots their showing. By the end of January according to these CFS runs from the early and Mid DEC data the SSTA's the esno 3/4 readings will be close to +0.6. Moroever take a look at the END of the graph... which is JULY 2007. Note how many models have dropped BELOW the zero line!!!! This has major implications for the Hurricane season of 2007 . Neutral conditions -- not El Nino not La Nina but LA NADA -- are now LIKELY for the Hurricane season 2007 and IF these models are correct we may be in a LA NINA for the late Summer / Autumn of 2007 which is very favorable for above average activity in the 2007 Hurricane season

There is No sex in the Champaign Room NONE

2006-12-23T16:31:00.000-05:00

After looking over all of the data from 0z 6z and 12z here on Saturday morning.... I see no reason to change the forecast and when I had a couple days ago. This is a Major event -- and I will go into that in a minute why-- with Heavy rains over I-95 cities rain to snow over central PA and central NY state... best snows over eastern OH western PA western NY northern New England.

The overall synoptic setup is simply hostile for the idea of seeing any sort of significant snow or even measurable snow in the I-95 big cities from this evening Monday evening. When I made this initial forecast a few days ago it brought a pretty strong reaction from a couple posters - one guy who posted here under the name WXROCK was pretty strident in his reaction as was a poster over at eastern (PETEPSU) in that I was somehow jumping the gun... that something COULD change and it the overall pattern was "unstable" .. with the implication clearly being that there might be snow in the I-95 cities.

I am not exactly sure how anyone could call this El Nino induced warm active southern stream pattern unstable. Anyone who looks at this urrent pattern thinks it is "unstable" either does not know how to forecast OR needs go back and take a look the dictionary and see what the word means. The one thing we do know about the current pattern is that it is VERY stable.

After seeing the 12z NAM/ WRF I am reminded of a comedy by comedian Chris Rock... for the GED class of 1995... no matter what the hooker tells you there is no sex in the Champaign room. Oh there's Champaign in this Champaign room But you ain't interested in that. You are interested in Sex.... and there is No sex in the Champaign room. NONE.

In looking at the 12z NAM I see what the Model is TRYING to do and how so many weather hobbyists and weenies out there are desparate that the 12z NAM is going to be correct that that IF it shifts another 75-100 miles there will be snow in the I-95 cities .... or to follow the analogy ... sex in the Champaign room. Yes as I said back on Thursday it does NOT make a difference what the 12z NAM / WRF or any other models are depicting... there is no snow in the I-95 cities.

Oh there's going to be snow with the system in the mountains western PA Central Western NY State and North New England but if you in the big cities in northeast you're not interested in snow in those areas. You want the snow in the I-95 Corner. And this pattern it doesn't make a difference what the 12z NAM / WRF is trying to shift the Low track to the east ... There is going to be NO SIGNIFICANT snow in the I-95 cities

I'll start off by taking a look at the 0z ECMWF. As you can see here at the first link at 48 and 72 hours the model clearly shows the phasing is beginning with the northern shore wave of dropping in across the Plains or WEST of the Mississippi River. This is a classic and critical piece of information and he take a look at all 32 of the official KU snowstorms... having the phase occurring WEST of the Mississippi River is the kiss of death. Taking a look upstream we see a closed 500 low over southeastern LABRADOR but it's not really a classic 50-50 low so there is no reason for the major trough coming through the Mississippi Valley to dig any further south and east As a result system develops a negative tilt over the Tennessee Valley which again is too far to the West. Time and time again if you take a look at the 32 KU snows storm events having the mean 500 trough developing a negative tilt either OVER or west of the Appalalchians is the kiss of death. Note the Low DOES jump to the SE New England coast at 96 hrs

http://www.meteo.psu.edu/~gadomski/ECMWF_0z/f72.gif
http://www.meteo.psu.edu/~gadomski/ECMWF_0z/f96.gif

we can also see this on the 0z UMET at 48 and 72 hrs... for major events strong model agreement between the ukmet and euro is hard to go against. Also note the BOMB like nature of this Big low
http://www.meteo.psu.edu/~gadomski/UKHEMI_0z/f48.gif
http://www.meteo.psu.edu/~gadomski/UKHEMI_0z/f72.gif

0z CMC shows the phase WEST of the Mississippi river the trough DOES go negative and the Low is over the Appalachians
http://meteocentre.com/models/gemglb_amer_00/gemglb_amer_00_panel.gif

12z MODELS
Here is the CMC at 48 hrs ... Again the Phase is just too far west. Clearly WEST of the Mississippi river. Looking over SE Canada we can see how similar the 12z short range CMC is to the 0z euro with repsect to the 500 Low over Labrador. The data still shows a weak closed 500 low NOT over or near NF but over se Labrador which does NOT help
http://weatheroffice.ec.gc.ca/data/model_forecast/611_100.gif

72 hrs we have a Monster M.E.C.L. -- major East Coast low pressure area
http://weatheroffice.ec.gc.ca/data/model_forecast/478_100.gif

0Z NAM/ WRF
as you can see the model here at 60 hours from the 0z run SAT does not show the northern branch dropping in and phasing with the southern system and that is becasue the model also still has closed 500 low. This allows for the phasing to occur further east and hence the whole system the dull for the east. Note that at 84 hrs the 0z NAM WRF shows the phasing OVER the Mississippi river valley
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/nam/00/fp0_060.shtml

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/nam/00/fp0_084.shtml

Again keep in mind that none of the other models on at 60 hours still have the southern system as a closed 500 low. This should be an alarm bell or warning flag that the operational NAM/ WRF solution is probably bogus

That being so... we see the same problem here on the 12z SAT nam / wrf run and is as plain as the nose on your face. Pay attention to the closed 500 low in the southern stream over the DELTA .. as you can see it is closed off.

48 HRS .... but comparew this to the 48 hrs 12z GFS...
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/nam/12/images/nam
of_500_048l.gif
NO hint of a closed 500 low over the Delta. http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/images/gfs_500_048l.gif
The result? once again the PHASE takes place OVER or east of the Mississippi river on the 12z NAM WRF which results in the whole system developing further east and is much more promising with respect to winter weather for the East Coast and especially for New England.
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/nam/12/images/nam_500_060l.gif
The 12z GFS says No way. Note that b/c the model does NOT show a closed 500 Low at 48 hrs over the Delta the Phase is further west.
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/nam/12/images/nam_500_060l.gif
12z Euro says the NAM / WRF idea is crap and the Low tracks over or Near PIT which is Very consistent with the last several runs
48 hrs http://www.meteo.psu.edu/~gadomski/ECMWF_12z/f48.gif
72 hrs http://www.meteo.psu.edu/~gadomski/ECMWF_12z/f72.gif

Interestingly no matter which particular short range model that we're using... they all showed that the actual trough axis develops a severe negative tilt which again I strongly agree with.
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/nam/12/images/nam_500_072l.gif
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/images/gfs_500_072l.gif

One the things that good forecasters look for with regard to major East Coast systems is the "negative" tilt of the trough azis which often leads to major surface development. But the other key feature that many forecasters DO NOT see is what's going on over central and eastern Canada. From November through the end of March or early April most of the time we do see a large 500 low which is commonly for to as the PV --or Polar Vortex which is typical situated over central or eastern Canada. But as you can see from these Upper air maps .. in this particular pattern really don't have a PV. There is a deep PV Lows over the Bering Sea as well as over Eurasia and over Greenland which is part of the + NAO phase. But there is no deep or even weak 500 low anywhere over central or eastern Canada.

What this means then is that the atmosphere right now is essentially out of balance--- the Polar Jet is zonal with the long stretches of the zonal flow from the central or eastern Pacific... all the way across North America....and ending over the central Atlantic where the +NAO is. This sort of pattern during the cold season months CAN be dangerous sign provided you to get a significant trough to develop a negative tilt some where over the eastern half of the US. Without a deep closed 500 Llow -- a PV-- over central or eastern Canada the pattern or trough amplification over the eastern US often leads to the Low at 500 7500 700 and the surface to undergo explosive deepening then moving into the southeastern or eastern Canada and becoming the new PV
.
Sometimes this can lead to a massive change in the overall attern but as of right now none of the medium-range models are showing that happening.

DEC 25-26 Low tracks WEST on 0z Data then 12z GFS shifts it back east

2006-12-21T13:32:00.000-05:00

No... no... No and No.

I have said before and I will say it again at least a hundred more times in this winter season. You do not get winter storms -- SEC MECS HECS -- on the East Coast simply because a weather Model shows a large 500 low somewhere along the coast. You get them by having certain features which ACTUALLY exists in the atmosphere -- NOT on a model -- synoptically BEFORE the event actually begins. Oh sure occasionally you get the rare synoptic scale event which are so dynamically strong that they can alter things on a regional synoptic scale but for the most part that really doesn't happen.

In a nutshell the 12z GFS Thursday run for this event over the eastern US on the 26th is not vaiable. Let me explain why.

Yesterday I mentioned how I did NOT like the 12z WED runs with regard to the 500 Low coming out of the Southwest and tracking through the Gulf Coast and up the East Coast. This is what we saw with a medium-range models last week on the system now leaving the Plains moving into the Midwest that produced the blizzard conditions in Colorado Western Kansas the western Nebraska.

Originally that system was supposed to track to the East coast and did not because the Models misdiagnosed or did not see another shortwave that dropped in and cause these two systems to phase much further to the West. This the issue that I expressed yesterday.

The 0z data on the operational GFS Canadian British and European models all supported this westward trend. The northern shortwave is coming in stronger on the 0z model runs as we get closer to the event and this results in the phase betwewn the northern s/w and the closed 5h low coming aross TX to occur MUCH earlier... Not east of the Mississippi River as we saw yesterday but now WEST of the Mississippi River almost in the Plains. This results in the system tracking much further to the West which is what I feared was going to happen
http://www.meteo.psu.edu/~gadomski/ECMWF_0z/f96.gif

http://www.meteo.psu.edu/~gadomski/ECMWF_0z/f120.gif

http://weatheroffice.ec.gc.ca/data/model_forecast/134_50.gif

Then along came the silly 12z operational GFS which is back to its old tricks. Now that model is developing a 500 s/w over se Canada at 96 hrs into a closed 500 low over southeastern Canada near Newfoundland -- a true 50/50 Low -- whereas on the data from 6z and 0z operational GFS did not show that!!!.
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/fp0_096.shtml
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/fp0_120.shtml

Because we now have a 500 low that's closed off near Newfoundland the two systems still begin to phase over the Mississippi Valley but now is forced further to the south and east and has result the whole system is shoved back to the east including the critically important 850 Low.

I do not believe that the shortwave moving through southeastern Canada at 96 hrs is going to close off. I think the 12z Thursday op GFS model is overdoing it on this system and this bogus development results in the model screwing up the entire event. There is NOTHING over Greenland and / or the N central Atlantic that would cause that shortwave to slowdown and close off over Newfoundland .

Even if you were to take the 12z to heart the low level warming and the inland track of the 850 low is NOT good for coastal areas from PHL to BOS. The 12z GFS taken verbatim can bring a decent snow inland over NY state and New England...

I think the entire solution here from 96 to 144 hours is bogus. The 12z CMC shows NO such closed 500 Low over se Canada at 120 hrs
http://weatheroffice.ec.gc.ca/data/model_forecast/colour_images/12_054_G1_north@america@zoomout_I_4PAN_CLASSIC@012_120.jpg

and the phase is too far for east coast fans to wise for snow.
http://weatheroffice.ec.gc.ca/data/model_forecast/colour_images/12_054_G1_north@america@zoomout_I_4PAN_CLASSIC@012_132.jpg

My view -- I still see this as a Appalachian snow event MAYBE... and even that may be too far east. I like the 0z euro idea track alot and given the numner of Lows we seen track through the Plains and Midwest this solution as shown by the 0z Ecmwf matches the seasonal trend

Looks like we have another Major trough moving through the Midwest -- with no real cold air -- 12/30-31
http://www.meteo.psu.edu/~gadomski/ENSHGT_12z/f216.html

SECL -- but NOT a SECS

2006-12-20T16:10:00.000-05:00

In the most prominent feature in the weather maps today here at midday is the massive low pressure area in the central Plains... along with the heavy snow over eastern Colorado... Northwest Kansas western Nebraska along with the heavy rains to the east.
I am mentioning this feature because of what the last few runs of the operational GFS have been showing with regard to the next system which drops into the Southwest and closes off as a 5h cutoff Low.

If you recall the medium-range models from last week most of them had the CUURENT Plains Low coming out of the Southwest yesterday tracking across the Delta and into the Southeastern states then tracking off the Atlantic Coast. Then the MR models showed a new shortwave -- A KICKER -- would come over the flat Ridge in the eastern Pacific... then drop SSE into the Great Basin while the closed 500 low started to track east. With the new system dropping SSE into the Vegas area... the SE ridge from hell re-exerted itself ... and thus the closed 5H low coming out of the SW states was FORCED over the ridge and hence a NE track into the central and upper Plains .

However now the focus is on that "kicker".... the new s/w that crashes into the Pacific Northwest and drops SSE Friday and Saturday. The 0z 6z and now 12z theOp GFS all take that new clsoed 5Low over the to the SW states due east... across Lower TX thru th Deep south and into / UP the East coast.

First let me assert that I'm not certain about this scenario we are about to discuss. From this point on I am operating on the assumption that the OP GFS models are correct with track of the 5H low and that a new or undiscovered s/w does NOT come in from the Pacific and drop to the Rockies . IF that were tio happen -- IF --- it would n turn would causes this 5H Low to track NE... just like the current Plains Low.

That being case -- again operating from this critical ASSUMPTION -- the synoptic set up at 0z 6z and 12z is a classic Text book case of WHY this East coast Low on 12/26 and 12/27 can ONLY be a RAINSTORM for the BIG cities of the Northeast / I-95... and WHY certain features must be present BEFORE the Lowe reaches the coast. To drive home the point even further this is a TOTALLY different situtation from the 11-13 FEB 2006 HECS event.... where the issue was which AREA was going to get bommbed with heavy snow and which areas were NOT. In this upcoming event there are NO such questions with regard to the Big cities of I-95 seeing heavy snow. Its not going to happen. Period.

Lets start off with the 5H synoptic set up from the 0z Models . At 96 hrs we see the 5H low in the SW with one s/w moving thru MN and the western Great Lakes ( GL) and a NEW s/w coming towards the Pacific NW. THis is feature I am worried that the models are missing or not handling right and it might drop into the Calif or Great Basin as I discussed above.

In any event by 114 hours on the 0z op GFS the s/w that was passing through Minnesota and a 2nd s/w is passing thru the Northeast as well. This does dump some cold air into the Northeast. But as you can see simply by looking at these maps there is absolutely nothing DOWN stream -- over se Canada or in the NW Atlantic that is going to cause the northern streams to slowdown. As a result the High-pressure systems which moved into the Midwest Northeast will quickly slide out to see as any sort of Southern stream system comes north.
http://www.nco.ncep.noaa.gov/pmb/nwtest/analysis/namer//gfs/00/gfs_500096114_s.shtml
http://www.nco.ncep.noaa.gov/pmb/nwtest/analysis/namer//gfs/00/gfs_500120138_s.shtml
By 120 hours we have all the ingredients with regard to the classic setting Over the Midwest for significant winter storm on East coast. In other worda the UP stream features look to be pretty good... with a discernible powerful s/w in the northern branch and we have a large closed ULL over eastern TX. 850 temps over the NE seem to be easily cold enough to support a major snowstorm.
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/00/fp0_120.shtml

Between D5 -D6 the operational GFS develops a very strong and important closed 500 low over Southeastern Canada which is often referred to as the 50/50 Low-- the upper low is located near 50 degrees north latitude and 50° west longitude. This is a very important feature for the development of a possible East Coast snowstorm pattern but there are other features problems with his overall set up. Note that the s/w that was over MB and ND is now plunging into the Midwest and beginning to PHASE -- merge -- with ULL coming out of Texas. However this is occurring too soon and as a result the 850 low and a surface low is going to take a track in land.

One of the primary reasons why this phase occurs WEST of the Appalachian Mountains... which is very bad news for snow lovers in the Northeast big cities but very good news for snow lovers in the Appalachians and potentially the Ohio Valley... is that there is NO polar vortex situated anywhere North America!!!. The position of the PV often sets up where the mean TROUGH position is going to be located.... so in this case IF we had a typical garden type late December PV over say Hudson's Bay... the mean trough would be set much closer to the East coast so the PHASE between this strong S/W in the northern branch dropping into the Midwest and a Southern system would occur further east which in turn means a better chance for more winter precip in the BIG I-95 cities. http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/00/fp0_144.shtml

Ya follow? Note that D6 the model does NOT close off a 850 low of but it IMPlIES one over southwest VA... and by 156 the 850 Low is over PHILLY whicvh is way way too far inland for snow in the I-95 cities.... its good track for heavy snow over western MD WVA western PA and central NY regions. By 168 hrs the rainstorm is over in se New England
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/00/fp0_168.shtml

Of course it's a possible that as the 500 low tracks Northeast the rain could flash over to snow and the 0z Models DO show really good wraparound snow and snow showers over portions of western MD Northwest Virginia Western Central Maryland eastern PA much a Southeastern New York and a good portion of the New England. Wrap around snow is better than nothing... BUT it aint real snow...

The op 6z GFS...
again we can see a really good synoptic set up occurring UPSTREAM over the Midwest as the two streams are phasing very clearly at Day 6. But as you can 850 Low is in a HORRIBLE position... well inalnd... and this is even more critical than normal because there is no sustained arctic flow or Cold High to the north. As I have already stated ....and as I am sure you are aware of... we are NOT seeing any sort of amplification in the northern branch over western Canada. Thus there is NO real cold air source to come south when the northern branch begins to amplify. As result even though we have a pretty good phase here at Day 6.5 the only air mass we have to work with is a Pacific air mass. And when you have any 850 Low that is so far inland .... well you are toast. It's just not going to happen with 850 track
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/06/images/gfs_500_144l.gif
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/06/images/gfs_850_144l.gif
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/06/images/gfs_500_156l.gif

The 12z OP GFS... is consistent with the last couple runs in how the overall set up is going to affect the surface track and the 850 low. At 120 hours the model is clearly showing the phase is occurring even FURTHER to the West and temperatures at 850 are much warmer on the 12z run for 12/25 than what we saw on the 0z run at 132 hrs!!!

And 132 hours the model has developed a closed 500 low over the Southeastern states and again that is fairly consistent with the previous runs and with what we are seen on other models.
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/fp0_120.shtml
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/fp0_132.shtml
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/fp0_144.shtml

As you can see the 850 low is now west of Roanoke Virginia and tracking NE which is a disaster if you like snow in the I-95 corridor. Note how the zero isotherm at 850 is well West of I-95 cities and 850 winds are 30-50 knots out of the SE. By D6... the 850 low is NORTH of NYC and still tracking and almost all of se New England is getting strong SE winds at 850 and winds at the surface.

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/images/gfs_850_132l.gif
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/images/gfs_850_144l.gif

The 12z GFS ensembles are showing very much the same sort of thing with no source of cold air to dumping to the system and no changes over eastern Canada would force the phase to occur further east. The operational midday Canadian at D6 is showing the same sort of thing with the phase occurring over to the WEST of the Appalachians which is just not a good sign for folks who want winter weather in the big season the Northeast. It is of course a pretty good sign for the mountains of the Northeast... the Appalachians.
http://weatheroffice.ec.gc.ca/data/model_forecast/colour_images/12_054_G1_north@america@zoomout_I_4PAN_CLASSIC@012_144.jpg
Finally here is the midday European and we can see at D5 the kiss of death here... note how the northern branch is now phasing with the Southern system over the Mississippi Valley which is significantly further WEST than what we were seeing on the earlier runs the European. It is also supportive of the trend that we are seeing here midday WED with the other models such as the 12z GFS as I have already discussed.... such as the midday Canadian and the midday UKMETl. Of course this is all assuming that these medium-range models are fairly close to reality here at Day 5. I believe they are because most of them are showing the same sort of thing and the same trend here at midday.

BUSTED ... well at least there is SOME Good news on the El Nino

2006-12-19T09:44:00.000-05:00

Well it's time to concede a couple of major points here as we move to middle December. The biggest one is that I'm wrong and that my forecast the second-half December is in the process of BUSTING. I supposed technically one could say well wait until the last day of December to make that call but really all you are doing as a forecast meteorologist is just playing some sort of stupid game. As a forecaster one should be able to figure out where the pattern is going even if we cannot predict the exact track of a low-pressure area this far out in advance.

The pattern is not going to repeat itself like it did in the late November into early December and we're not going to see another +PNA redevelop... and there is going to be no surge of even seasonally cold air back into Most of the CONUS. Its called a forecast BUST... and I have got it.

As I stated in the last column last Saturday and Sunday when the medium & long-range models took the evolving pattern in a whole new direction... not just with the low-pressure area coming out of the Southwest track gained thousands of miles further to the north and west than originally thought... but also with the breakdown of any even moderate +PNA ridge... I fairly quickly deduced that the entire forecast Idea that I had for the second-half December was rapidly headed into the crapper.

The primary reason that I was able to adjust forecast and come the conclusion that my overall view all of the second-half December was going to bust without having to wait for 12/31 is the use of the technique that I call SOE or sequence of events. Just because I had developed this idea for a return to seasonally cold temperatures in the second-half of December does not mean that my ideas were going to be correct. I had a backup plan and I knew that if there is not going to be returned to a seasonally cold pattern over central and eastern North America... the odds which strongly favor the mild El Niño induced pattern continuing. Thus once I saw the shift over the weekend in the models I bailed.

At this point let me congratulate also one particular forecaster who went for a very mild December across most of the CONUS. He's an undergraduate student at Millersville University and has above-average meteorological skills for an undergrad. In fact if any of you traders out there are interested in scooping up a hot rookie prospect from the minor leagues and into your team/ company send me e-mail and I'll tell you how to reached this Guy. You could do a lot worse than pick up this Guy fresh out of school and quite frankly I think if he went into the government it would be wasted his talents.

On the other hand I am encouraged by one piece of data which came out yesterday and I'm sure that by now some of you heard / read. Over the last two weeks or so I've been talking about how the El Nino evernt SEEMS to have reached a peak or a plateau... and I was citing the sub surface SSTA as proof that the large areas of very warm waters underneath the surface in equatorial Pacific waters were weakening especially on the western side near the dateline-- ENSO region 4 and 3.4.

Yesterday the enso 3.4 region dropped from 1.4 to 1.3... the first drop since the 1st week of SEPT. Moreover the AUS folks data shows even further weakening of the El Nino with the SSTA in ENSO 3.4 dropping to +1.19!!!

To be sure such a minor drop is not that big a deal BUT it does have significant implications. First it does seem to support the idea that there is a connection between the warm sub surface SSTA and the surface enso readings. All during the Autumn when the sub surface temperatures for rapidly warming the El Nino moved steadily from weak levels of SEPT and OCT to moderate in NOV and DEC. Second there is of course the chance that the El Nino might surge back to +1.4 or maybe even +1.5 but given the fact the last three weeks it has held steady... and now see this drop... any sort of rise in the next 2 weeks would be a temporary aberration and I think it's safe to say that the ENSO has peaked. The data is increasing that the El Niño is beginning to weaken but I am not yet convinced of that because it is still a Little early to make THAT call. Come next Monday 12/25 IF the SSTA in enso 3.4 holds steady or weaken again THEN we got something!!! THIRD... in the WINTER forecast I maintain that if you look at all winter when there was a weak SHORT LIVED La Nina (like we had in 2005-06) that was then followed by a El Nino the very next winter... None of the El Nino reached a sustained moderate El Niño that lasted all winter. At Best there were couple of instances where the El Niño briefly reached moderate status for a one-month period but then dropped back into the WEAK El Nino thresholds.

Again the data seems to be supporting that idea but I'm not yet ready to declare victory on this concept just yet.

The working theory about how a weakening El Nino might affect the JAN FEB MAR -- IF it is indeed weakening -- goes like this. The data is overwhelming that when you have a weak El Nino event temperatures run below normal and sometimes significantly below normal over the central and eastern CONUS. Good examples of this are the winters of 2002-03 or 77-78 . Back in September and October 2006 when the El Nino was really developing it was of course still "weak" and not surprisingly the months of September and October 2006 the first time in several years we saw back to back cold months. Then inNovember when the El Nino reached moderate status the pattern turned dramatically wamer within a week or two of seeing the El Niño reaching the threshold over +1.0 in enso region 3.4. I guess by now you can see where this is going... IF the El Nino is weakening and it does dropped to +1.0C by the end of DEC or early JAN 2007 then we may see a return toward say cold pattern much like we saw on September and October. Sounds far-fetched? Maybe it is but a does seem to work and awful lot of time and I'm not one that gets wrapped up in hair brain far-fetched schemes and ideas very often.

Synoptically the pattern remains a very warm one dominated by the Pacific jet. The big ULL in the southwest states moves out of the Rockies and across the central Plains next couple days and bring that area significant snowstorm and pass well west of Chicago. The problem is of course that such a track is only going to reinforce the warm air over the eastern third the US. Another strong s/w crashes in the Pacific Northwest this weekend and drops southward into the Rockies and the great Basin once more bring that area another significant snow... and that to also closes off over Southwestern Texas 12/24. That Low is over the southeast coast on Christmas night and there is a weak HIGH over the Northeast... but that High is made up of Pacific Mild air and will slide out to sea . There really is nothing to be overly excited about in terms of winter weather temperatures patterns or threats through the end of the month. There are some interesting thing showing up at Day 12 or Day 15 on some ensembles but until I see more proof that something is going to change of the high latitudes I will remain very cautious.

if you like COLD & WINTRY weather in the Eastern US; 0z runs are a disaster

2006-12-16T10:20:00.000-05:00

well taking a look at the 00z Models there really is only one term to describe the medium-range models in the overnight period-- and If you love winter weather and cold that term is DISASTER.

So complete is the model reversal from the data on Friday that the East Coast stays warm right to Christmas. Keep in mind that the 12z Thursday and 0z Friday runs was showing this Low coming out of the Southwest tracking across Southeastern states and then to Virginia. The trends started to shift the track of the SW Low yesterday on the 12z runs... and now the 0z Saturday runs have continued the trend... taking this system well west of Chicago!!! That is a huge shift in the models in just a 24 -36 hr hour period!! And even though the event for the 12/22-23 is still 6-7 days out is remarkable to see that sort of massive shift in the medium-range models in such a short period of time.

The question is of course.. is such a shift correct? One of the rules are using medium-range forecasting is the rule of Model consensus. At this point in time and skill here in the early 21st century weather Models are of such high quality that when you see a massive shift like this in ALL or Many of the models -- be it SR or MR --on a particular run cycle ...such as 0z or 12z.. nine times out of 10 it usually means that the medium-range models are correct.

What has changed... that IS obviosuly the BIG question? Well several things . To begin with if you go back and looks at the MR runs from earlier this week you'd see some sort of Ridging developing over Greenland for next week and while it would not really constitute a classic - NAO the 5H rise over Greenland that the models were depicting would force the system in the Southwest tract further to the south and east keep in the lower latitude. Now None of the 0z models are showing that sort of Ridging now over Greenland.

Second many of the MR models from mid week shwed SOME sort Ridging developing over western Canada... yet if we look at most of the medium-range models at 0z we ee that there is no hint of that on the 0z runs through Day 10. And the 0z CMC and GFS ensembels are not much better.

In my view the prospect that the 0z Models are all wrong is NOT very good. We still have a time to hope that the models might shift back but if they haven't done so by Sunday the threat of ANY event for the East coast be it rain or snow... Is over. Moreover if we have not seen a shift back to the type or pattern we are seeing on Wednesday Thursday and Friday then the prospects of that the last week of the DEC would be even seasonally cold are greatly diminished as well.

Interestingly if one or to take a look at the SSTA the large bubble is very warm air located off a Southeastern Canada in and around Newfoundland has now completely collapsed.
SSTA map 0z 12/15
http://weather.unisys.com/surface/sst_anom.html

SSTA 0z 11/18
http://weather.unisys.com/archive/sst/sst_anom-061119.gif

This could as significant implications because when that pool very warm was in the Davis straits in late Septmber & October THAT is when we had the sustained - NAO over Greenland. Later when this pool of very warm SSTA moved South into and around Newfoundland... that is when the -NAO collapsed and we moved into the sustained phase of +NAO patterns.

Now however it appears from this data that we going to another change in the SSTAs in and around Southeastern Canada and in the far NW Atlanric. What exactly this means or whether not the pool very warm water in and around Southeastern Canada might re develop is hard to say. But if it does not this development -- and breaking down of the pool very warm water around Southeastern Canada could have significant implications down the road.

12/23 all rain for the NE right? well probably but there is an scenario

2006-12-15T09:10:00.000-05:00

I will try to make this addition of shorter than the last few posts but I usually end up saying so much that such an endeavor never really works out.
The first issue to deal with it is the cold front that comes through the Northeast sometime on 12/20. The overnight run of the European has brought back the Wave development on the front a little bit. This idea is generally supported by the 0z Ukmet
http://www.meteo.psu.edu/~gadomski/UKHEMI_0z/f96.gif

http://www.meteo.psu.edu/~gadomski/UKHEMI_0z/f120.gif

but the operational runs of the GFS in the Canadian show NO development until the northern stream short wave is way out to sea. However if one were to look at the GFS ensembles we would see that many of the members to show a somewhat more amplified short wave moving through the Northeast when compared to the 0z operational GFS
Please note c000 p001 o002 p003 p004 p008
http://www.meteo.psu.edu/~gadomski/ENSHGT_0z/f132.html

CMC of 0z ensembles
http://www.meteo.psu.edu/~gadomski/ENSCMCHGT_0z/f120.gif

In any event this potential feature is not going to be a big deal or even a significant event for that matter. It wasn't for the fact that we are enjoying a very mild December here in the Middle portions of the month this wave development would not get much if any mention at all.

All right lets move on to major closed cut off 5h Low over the Southwest states coming out in one piece. I think at this point in time we can safely rule out the idea that the system is going to turn N into the Central and/or Upper Plains. It looks like it as this upper Low tracks across southern New Mexico and Central Texas it's going to produce a major snowstorm for many of the livestock areas in the lower Plains possibly as far north as southern Nebraska 12/19-20. Once the system crosses the Mississippi River the temporary surge of cold air in the Northeast will be gone and as a result the large rainstorm we are likely to see from this upper low crossing the Deep South will spread into the Middle Atlantic states.

At this point it would seem safer to forecast a complete rainstorm for a major cities of I-95 and I don't see any real reason to go against that idea. As I mentioned in the winter forecast the stormy pattern we saw in October and early November was an indication of the type of winter pattern we could see in January February & March. But more importantly this is a really textbook case of why certain features have to be in place in the upper levels of the atmosphere for a major snowstorm or even a significant snowstorm concur on the East Coast. It's not simply just a matter of how in a large deep slow-moving low pressure area during the winter months.

That being said there is a scenario where as the SE Low begins to move up the coast on the 23rd fact we may yet see significant snow over some portions of the Interior middle Atlantic --- ie mtns -- and the Northeast -- well inland. here is How that COULD happen:

First lets deal with 192 hrs -- the 0z European model as the primary Low pushing fairly far to the north... across the Ohio River. Without a large cold High-pressure area in place over southeastern Canada or northern New England IF the primary Low tracks that far north and is below say 1008 MB then you often have a significant warm air problem for the big cities of the Northeast. Indeed that is what the operational European is showing but I'm curious as to why the primary Low tracks that far north given the ULL stays fairly far to the south. So that's one aspect to keep mind over the next several days.

Second and again this is on many of the medium-range models as well as the ensembles... is the appearance of a important short wave which appears to drop into the Northeast just as the 5H Low is over the SE. Now this sort of scenario is what I call a " timing problem" and by that I mean everything has to work out just right -- "in the nick of time" to get the cold air into the Northeast while the Low is still close enough to the coast to change things over snow. We see weather models do this an awful lot in the medium-range and it's exciting to watch but for the most part its very uncommon .

Recall that in yesterday's post I mentioned how none of the ensemble members were showing the confluence zone PJ (Polar Jet) close enough to the Northeast to produce source for a cold HIGH to form.... all the members on that the data yesterday showed that Polo get region still north of the Great Lakes and over Central Ontario and Québec... hence no cold air source

However that is not the case on this morning 0z GFS ensembles. For instance if we were to take a look at the 180 hr GFS ensembles members we would see several members trying to drop the PJ much further south and phase a northern short wave into the 5h closed Low over the SE states. P007 P008 P009 and c000 all show the phasing occurring in the "Nick of time" scenario I mentioned above.
http://www.meteo.psu.edu/~gadomski/ENSHGT_0z/f180.html

This is probably the ONLY way given such a warm régime that one can get a snowstorm in East Coast. If you want to see an analog as to how the 500 pattern could phase and let me emphasize again this is COULD not certain... not likely... not reasonable... just COULD then take a look in your KU snowstorm books at February 8-10 1969. That being said the odds are NOT good for and event like that happen. Every winter I see MR and LR models showing this type of development and every winter is often falls apart.

Interestingly prefer the 6z op GFS is closer to this idea than the 0z and matches those more aggressive 0z GFS ensembles.

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/06/fp0_180.shtml
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/06/fp0_192.shtml

For the time being I think there is a good possibility that the Interior portions of the Mid Atlantic and by that I mean the mountains and the inland areas over New England have a CHANCE of seeing a decent snow event in this but I'm still in the speculation stage and I am not committed to this idea.

Even as we go beyond this possible event on 12/23 the overall ensembles look very impressive... with regard to storminess. The operational 0z GFS at day 10 looks very similar to what we saw on the THURS 12Z run and almost every single member in the GFS ensembles shows some sort of major short wave on the verge of phasing or about to phase between the two branches. I still see that the overall pattern in the last week at December has a lot of potential.

http://www.meteo.psu.edu/~gadomski/ENSHGT_0z/f240.html

12z thurs 12/14 SPECiAL

2006-12-14T13:00:00.000-05:00

The TREND is MY friend but it aint yours !!!!

The midday American model h turned strongly towards the 0z Euro and how it handles the SW low 12.22-23 which IS a winter storm RISK for the Middel Atlantic even through the 12z THUR op GFS model shows a the SW Low sliding off the SE coast as a Flat wave

If you recall from this morning the problem was that the Operational 0z and 6z GFS took the 5H low ut of the Southwest states and merged it with another s/w coming in from the upper Plains. This system then drop heavy snow over Texas and Oklahoma as well as portions of eastern Kansas Northwest Arkansas and Missouri and significant rain for the deep South and Midwest and East Coast. And it was not until this Low pressure area cleared East Coast on the 22nd the cold air finally return.

The midday op GFS model is different and much closer towards the European British and Canadian solutions from this morning. It now shows the northern s/w is NOT going to drop into the Low over the Southwest states but instead track through the Midwest as a very decent system in its own right and development significant rain and/or snowstorm for the Midwest and New England 12/19-20. Hello 0z ecmwf and ukmet!!!

The trend is my friend

If we were to accept the American model solution here at midday "verbatim " this system would bring significant rain to the BIG cities of the NE such as Philadelphia New York and possibly Boston... and significant snow to places such as Indianapolis Detroit Toldeo Leo Buffalo Albany and much of New England

Then after this first Low pressure area passes off the coast the Low over the Southwest states and the lower Plains comes eastward. The midday American model is weaker with this BIG Low coming out of the SW and thus does NOT show a major snow fall for OK NM northern and western Texas. Instead this system just brings rain to central and southern Texas and moves across the Gulf Coast 12/21-22.

BY the 12/21 -22 the 1st Low moves thru the NE and has passed through off the coast and cold air moves in... reaching into KY TN and northern NC. The midday American model takes the Low over the Gulf Coast states and suppresses it by moving it off the Southeast coast BUT the pattern actually favors this Low over SE NOT sliding off the Southeast coast BUT turning NE and with all this cold air in place the potential would still exist for possible winter storm for the Middle Atlantic Coast12/22-23.

There is a Noitceable 50/50 In place as well a ICELAND Ridge ....
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/fp0_180.shtml

By Day10 ( 12/24) seasonally cold air covers much of the central and northern CONUS and there is a fairly strong Ridge over western Canada. But the Jet stream here has split which means that energy is coming in on the southern into the West coast UNDER the ridge over western Canada. This is often a very stormy pattern for the CONUS and the Midday American Model shows a very potent system diving Southeast into the over the central Rockies / Great Basin on the 24th-25th while a large cold area of High pressure stretches from Southwest Canada all the way into Buffalo. If we take the Midday American Model verbatim at day 11-13 this run is screaming a major snowstorm for the Midwest and the Northeast.

264 hrs Major 50/50 is in place which is why this LOOKS promising
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/fp0_264.shtml

288 hrs more of the same DONT sweat the 850 temps at this point
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/fp0_288.shtml

Not surprisingly behind this winter storm the model shwos more significant cold air in the 11-15 day. In My opinion I think the American model at midday is much closer to reality than what we were seeing this morning. I am of course very uncertain about the potential for major winter storm across the US right around Christmas but the potential so there and it has to be watched.

The SE Ridge from Hell... ENSO update

2006-12-14T09:03:00.000-05:00

Lots of talk about this morning you sick twisted freaks so let's get right to it.
First off lets looks at the December 12 subsurface temperature anomalies for
the El nino regions. You can see from this latest Link there been significant changes over the western portions of the current El Niño... which would be regions 4 and part of 3.4

http://www.pmel.noaa.gov/tao/jsdisplay/plots/gif/Dep_Sec_EQ_5d_anom_comp.gif

This becomes even more obvious when you compare it to the data from let's say November 22.... which you can see here.
http://www.wxrisk.com/MODELFOLDERS/today/nov22.jpg

Now taking a look at this one can easily argue for example that the area of +4c temperature anomalies below the surface is RISING as it moves east towards a coastal Peru and into El Nino regions 1.2 But what I think is for more important is that the western side all of the current El Niño which back on November 22 showed a large area of +4C and +5C has weakened a dramatically over the last couple weeks. Assuming this that is correct and assuming that my reasoning is also valid... then I suspect after this current warm bubble that is moving into the subsurface regions all of enso 1.2 passes through-- by the end of December 2006... that the overall ENSO will begin to weakened at a pretty steady pace. Unless there is a new surge of really warm subsurface temperature anomalies developing out by the dateline - enso region 4... then it is looking to me that by the end of DEC the worst of this current El Nino will have already pass-through and reached its peak. Anyway that is what the data is looking like to me .

There is some dispute within the various energy forecasting companies as to how cold and how soon the cold front is going to move through the Midwest this weekend and the Northeast early next week. This is mainly due to the wide discrepancy in the medium-range models about what happens along the front itself and the synoptics upstream . The operational European MODEL from overnight has a wave a Low pressure developing on the front that cuts across KY WVA into MD and ends up bringing the first decent snow of the season to portions all of northern Pennsylvania New York State and much of New England. However the 0z and 6z GFS say No dice... and are much slower with the cold front at a much stronger Ridge over the Southeast which really does not break down until DEC 22!!!

Now why is the GFS showing this? Well I think it's the same problem we had yesterday -- the GFS model trendency to over phase the "streams" to soon. Recall the 12z WED GFS which had the Low coming out of the Southwest states ... then phasing that feature with the next s/w dropping in on the northern stream -- and hence we had a major Plains snowstorm. Of course all the models now totally different with that solution... but the key point here for you do understand exactly GFS appears to be doing this again on the 0z and 6z runs day D5 and D6
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/06/fp0_144.shtml

With these 2 s/w phasing over the Mississippi valley the 0z and 6z GFS solutions actually end up reinforcing the Ridge over the Southeastern states as result the warmth stays over the East Coast until the Midwest low reaches the Coast on 12/22.

The operational Europeans does NOT phases these 2 s/w and keeps the northern s/w completely separate as it moves through the Great Lakes and spins up the Low pressure area on the cold front and hence the New england snowstorm.

The problem is of course trying to figure out which solution is correct. And this has longer-term implications because IF the GFS is screwing up D5 and D6 then it is may be getting the rest the pattern completely wrong as well. Ya follow?

As you can see the operational Ukmet and 0z CMC does NOT support the 0z and 6z GFS and they are both strongly within the European Camp. The northern shore wave does NOT drop into the system coming out of the Southwest and instead of blows on through in the Northeast and drives cold thru the big cities the Northeast much faster than what the GFS showing.
http://www.meteo.psu.edu/~gadomski/UKHEMI_0z/f144.gif

http://meteocentre.com/models/glb00_144_4pan.gif

To looking at the 0z GFS ensembles we see several of them but not a convincing majority also take the northern shore wave across the Great Lakes and/or New England....p001 p002 p004 p007 p008 p009 .

In any event if we go beyond this problem with the solutions at Day 6-7 and/ or the position of the cold front and/ or the possible wave development on the front which might bring snow to New England... we then have to look at the actual system coming out of the Southwest itself!!!!
The operational European is much slower with the system coming out of Southwest which again could be the model bias of this model kicking in... with the result that we see a snowstorm over western northern Texas western NM and OK 12/20-21. By December 23 the model has the Low again on the East Coast -- either over Southeastern Virginia or off the Delmarva-- which is consistent what the model was shown yesterday... but there is no cold air over the cities of the Northeast or the mid-Atlantic so it's just a large heavy rainstorm. Inland the 0z Euro is showing significant snow possible over West Virginia Western Virginia as well as western Maryland and south-central Pennsylvania.

I have seen the European ensembles and they are significantly faster with the system--- both within coming out of the Southwest US and how it reaches East Coast and in knocking down the SE ridge .

The operational CMC GFS both 0z and 6z are also faster than the operational European and show pretty significant system somewhere over the eastern third US in the days right before Christmas say December 22 or the 23rd . The problem is again that there is no northern branch of the Jet stream close enough to the lower Great Lakes / southeastern Canada that can act as a source for a cold surface High to develop and as a result this system appears to be mainly a rainstorm for the Northeast big cities but could be a significant snowstorm for the mountains... from say West Virginia into central northern New England. This tendency is strongly supported by the Canadian and GFS ensembles.
http://www.meteo.psu.edu/~gadomski/ENSHGT_0z/f192.html

There is a chance at some portion of the Midwest could see snow out of this if they are exactly in the perfect NW quadrant and temperatures are just cold enough... but even so many areas of the Midwest would see heavy rains.

As you go out to d10 and beyond that is when I think the pattern has more potential because then will have the cold air in place with the new +PNA in position. I have never been a fan of trying to forecast winter storms in a very warm pattern and then counting on the model Day 6 or D8 trying to forecast the cold front to move in just in the "nick of time". Those sorts of scenarios are really fantasy and very very really happen and most of the time when they do its up across the northern tier states such says Minnesota the Great Lakes or northern New England. In any event event I think I have to figure out what the actual solution is going to be with regard to the system coming out of Southwest first and how fast or slow does the SE ridge last... before we get into any details about the week 2 forecast.

Pac NW to get battered for at least another week; +PNA to develop after 12/20

2006-12-13T09:04:00.000-05:00

Assuming that I'm up and about at a reasonable hour in early in the morning I will endeavor from on to have this plot updated everyday by 730 --800 am EST ( weeekend somewhat later).

There really is not much to change in the next five or six days with how this is going to unfold from the current mild pattern back to a +PNA pattern by DEC 22-23 . The first important piece the puzzle is going to be the songs shortwave which crashes into Seattle or lower Vancouver Island Thursday night and races east along the US Canada border ... tracking north of the Great Lakes on Saturday and Sunday. This is an important feature because the trailing cold front is going to drive south and east across the Upper Plains the Great Lakes and into New England . This front will then probably come to a halt in a sw to ne direction 12/18-19 roughly on a line from eastern Texas thru the Upper Delta... very close to the Ohio River then close to the Mason Dixon line. The European i & Canadian models develop a weak wave of Low pressure on the front while the operational 0z GFS and Ukmet do not. This wave is going to the first forecast problem to deal with in eastern US because if that wave does actually develop we may see some overrunning when to whether north of front across portions of Ohio Pennsylvania and New York.

Longer term the problem is what happens in the southwest US. The operational GFS this morning at Day 7 has a deep close ULL over the southwest which comes about because the models biased to over phasing systems. The energy from the northern branch in western Canada faces and the model develops the ULL too far west on the 0z run. This is in stark contrast to the operational 00z European and Canadian which do have a close the 500 low over the southwest but those models have the closed ULL significantly further east and they do NOT show a CUTOFF Closed ULL. This implies the 500 low in the SW is going to be a lot more progressive than what the operational 0z GFS is showing.
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/00/fp0_180.shtml
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/06/fp0_180.shtml

The 0z GFS ensembles do NOT support the 0z GFS operational run... but do strongly support the European Canadian solution. Really this should be a TEXT BOOK case where one should be looking at the ensembles rather closely... whenever you have a synoptic situation where there may or may not be a close to 500 Low hanging back over the southwest then the ensembles really have to be used very heavily as operational medium and long-range models have a tendency of screwing up the solutions pretty badly.
http://www.meteo.psu.edu/~gadomski/ENSHGT_0z/f180.html

Obviously this is important because if the system it does hang back as far to the west as the 0z GFS is showing dandy rage over the Southeast is going to be significantly stronger and a cold front is delayed at least a day may be to perform reaches East Coast. As a result the 0z GFS doesn't have a cold front reaching East Coast almost the 24th whereas the operational European and Canadian are much faster.

Taking a look at the 6z op GFS we see a much more realistic run that is a lot closer to the GFS ensembles mean as well as the operational European and Canadian. You going to see me refer to this as a RULE many times this winter and even to the summer months but whenever the 6z operational GFS turns around and shows a solution that is similar to the 0z Euro it's a pretty good sign that the European solution is more likely be correct.

That is not to say I do not have a problem with the operational European this morning at D7. I most certainly do. Usually when a clsoed and cutoff 500 Low forms over Bja Calif or NW old Mexico the s/w energy drops down along the west coast of North America then along the coast of California. But in this particular case the model forms that piece of energy on D6 which gets left behind and then intensifies and retogrades. This sort of development is not really supported by the European ensembles is morning. On the other hand I do liked what the European Day seven is depicting that shortwave moving through the Great Lakes and ushering in a reinforcing shot of colder air across the Northeast.

No matter which model you prefer the key point here is that by Day 7 the overall pattern shifts from a unified flow into a split flow with two distinct branches.... and that always leads to some interesting whether in the winter months especially when you have a Moderate El Nino.

What happens by Day 8 & Day 9 is that the operational European develops a a strong ridge in the Northern Branch which allows a shortwave to drop and amplify into the Plains states as the southwest low comes out across southern Texas. In this situation if we could keep a 50/50 Low in place then we would have a pretty good shot for a significant storm on East Coast say 12/23-24. But the operational European doesn't show the 50/50 Low over NF holding so as a result when the two systems meet or "Phase" it occurs to far to the WEST to be a East Coast winter storm and instead we are looking at Appalachian event where places like Pittsburgh Columbus Ohio West NY state and even Greensburg PA could see significant or even heavy snow.
By 12/24 we are back into a full bore +PNA pattern with seasonal cold over much of the central eastern US and many the models showing some sort of significant storm thread on Christmas Day. Taking a look at what say the 300 hour 0z GFS ensembles either dropping into the Plains states and/or head towards East Coast... C001 p002 p003 p007 p008 p009 p010.

I've particularly liked the 6z GFS idea at 288 hrs...
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/06/fp0_288.shtml

Last point I want to make regarding good feedback question I got yesterday regarding the pattern. Earlier this season and in my winter forecast I stressed how it seemed that no matter what happened with the pattern we were getting East Coast Low to forms ... but now I appear to stressing that we are in this repeating cycle where the mean trough is forming out over the west coast we can ridge in East and pattern progresses and return cold East with several days of a +PNA forming... and arent I contradictring myself?

Yes that person has a point --I am changing little bit here because for one thing the blocking pattern we had during late September October and early November is no longer in position around Greenland. SECOND ... is that during the month of November the El Nino did strengthen from a weak event to a modern event and there is a lot of research which shows how significantly different the overall pattern to North America run between a weak El Niño event versus a moderate want..

Thus I have changed the ideas here in DEC a bit in this regard from what we saw in October and early November. Again this is a way I do thing and it is a point on which some forecasters and some weather hobbyists do NOT like. The data changes so the forecast has to change. It's not about my ego... It's about getting the forecast right and IF that means I have to change how I see things developing in this 1 portion of winter for a few weeks I do so. This is in stark contrast to some of the other forecasters out there who have latched onto the warm winter dogma and who have continued to deny that cold air at any time is ever coming and totally missed the cold outbreak we had a first week of December... and even now are way behind the eight ball this morning WRT the developing +PNA pattern we see developing in the days right before Christmas.

Models hinting at SECS / MECS day 9-10

2006-12-12T07:50:00.001-05:00

afternoon idea I will post in the feedback section

Before we get into this morning's synoptic discussion I wanted to clear up a couple of points. First there is this contention that I have or that I did forecast a colder than normal winter over the eastern half of the US. That's not correct... MY winter forecast is very clear. The issue is colder than expected. While many of the weather wennies and even a few professional meteorologists that post on some of these weather boards have gone for a colder than normal winter (this really should come as no surprise to anyone since this is the popular thing to do).

Many of these same forecasters also did the same thing last Winter. However my winter forecasts are aimed at people who have to deal weather on a professional level such as those who might have a Ski business... Or run a transportation company or trade energy or agricultural commodities. In that respect many of the winter forecasts out there as well as what the General public perception from the Media IS for a milder than normal winter. Now if you are a weenie and you are incapable of looking at anything outside your own naval (or in this case your own PC) you probably don't realize that there is a heavy perception out there for a Moderate El Nino / Mild winter over much of the CONUS. However it that's not my problem... It's yours. The fact that you may not about it only speaks of your ignorance. Just because you don't see the moon on a cloudy night doesn't mean the moon isn't there. Just because you may not know although overwhelming consensus for warm biases this winter in the various consensus forecasts--- outside of the weather boards-- doesn't mean it is not there.

The second point I want to speak about again before get I get to the synoptics ...is the idea that because I am relocating to a more favorable winter climate that somehow another I am more positive or aggressive about the prospects for this winter in the Northeast/ Midwest. That would be true except for the fact that I made it very clear back in August and September long before I knew I was relocating that I was excited about the prospects for this winter. In fact way back in March & February 2006 in some discussions I had with other meteorologists over at easternuswx.com ( HM to be precise) I made several assertions about how I thought the winter of 2006 --07 was going to be a much more active winter then 2005-06.

I suppose someone could make the assertion that I am just being a contrarian. I suppsoe there is SOME truth to that but mostly it is that I am a skeptic when it comes to things that everybody called "knows" to be true. If "everybody" knows that it is going to the very active hurricane season I am more likely to go the other way until I am absolutely convinced of ALL the data. And when I see pieces of data sticking out like a sore thumb which doesn't seem to support the general consensus well that always sends off alarm bells in my head. If I think everyone is going for a colder than normal winter and I see data sticking out and arguing against that idea... well I am going to go the other way. I won't go the "other" way simply to piss people off but if I see data which is sticking out and I think it significant I will not change my mind either. For me it's a constant feedback process and walking a tightrope between being contrarian vs coming across as a crackpot. Between being sticking with ones ideas but not being so fixed that you can see the train coming down the tracks if you are going to be wrong. It is a Fine line ... and its call the Art of skepticism... if you want to read more about this philosophy and how I used it... you can read at this point here.

http://www.wxrisk.com/Meteorology/skepticism.htm

OK let's get on to the actual some synoptics... it really is quite amazing to see the pattern repeating itself in the general overall sense as we move into middle of December and begin to look at the end of the month as well. It is in this same general overall sense that the pattern is redeveloping itself and if you can see this early soemtimes this can help a forecaster figure things. of course Just like no 2 patterns are exactly the same... not 2 analogs are exactly the same.

The first big event is the major system which is going to slam into Washington State on Thursday. Now I have several clients out of Pacific Northwest ... and back in late OCT at the Earthsat energy conference a lot of forecasters were NOT willing to go for the active winter in the Pacific Northwest with the general consensus that precipitation would run Below Normal over the very important Hydrological areas over all of the western US and especially in the Pacific Northwest. I argued that since I saw the vortex setting up in the Gulf Alaska either in the eastern Pacific or alongf the coast of British Columbia... that either position would (for the first portion of this winter at least) set up for very stormy Pacific Northwest. Unfortunately I was the only meteorologist that argued that position .... and in case you have not noticed its been damn stormy November and December over the Pacific Northwest and its going to get worse before it gets better. In my Winter forecast I argue for a essentially negative PNA and I see no reason to change that this particular time.

The reason why this Low-pressure areas important is because as it slides east along the US Canada border into the Great Lakes by the 17th and 18th. This sends a cold front through the Upper Plains the Midwest and the Northeast and that sets up a seasonally cold air mass in place. Then a Major s/w ( short wave) drops into the Great Basin and spins up a huge system for the Rockies while warm air from the Ridge over the SE sends warm air surgingnorthward. But because this time around we have a seasonally cold air mass in place over the Midwest and the Northeast it's going to take some time before the warm air surges north.

Eventually of course the big Low over the Plains states will move into the Great Lakes and when it does the warm air WILL surge into the Midwest and ortheast but it won't be quite as long with the extended warm period as well what we saw in late November.

Now looking beyond Day 7 I am sure many of you have seen the operational European attempting to build some sort of Ridge into southern Greenland. While this is a very encouraging sign it's NOT a "blocking Ridge" . Right now it's just an extension into southern Greenland. It qualifies as a negative NAO but its not a idea -NAO. Still it is better than nothing.

The next point to talk about is what happens again after Day 7. A couple days ago when the Model data showed a weak cold front followed by brief cooling then more Pacific Energy coming. This lead many to think -- and rightly so -- that any cold coming in after 12/20 over the central and / or eastern CONUS was not going to last and the cold pattern was not going to be very significant.... see my last Blog entry for more on this idea. There I mentioned last Saturday that one of the things I was concerned about was how in mid-November when it look like we were going to turn cold the early models at day 14 ... day 11 day 9 were just showing a brief cold shot and an as we got closer and closer towards the end November into early December the +PNA began to develop and these Bigger cold blasts satrrted showing up on the models. Now here were are a couple of days later and suddenly the 0z ecmwf 00z GFS and 6z GFS are all significantly colder as well... as we head towards Christmas.

It's pretty amazing to see how the models are just repeating the cycle again and I suspect this is going to continue. So if you are reading meteorologists say .."well sure the cold front on 12/21 will knock down the ridge over the Southeast for a few days but it wont last...' you may be reading somebody who may not be understanding the pattern. It seems to me that each new run we see bit more about colder pattern setting... and a but more of a +PNA ... and this is all very similar to what we saw in how the medium-range and extended range models were handling the pattern back in Mid and late November.

As you can see I am a pretty big believer in seasonal patterns and I like the way this SEEMS to be shaping up. It may be we could go through the entire winter this way!! The major trough comes into the West coast ... the ridge develops over the SE ... there is some sort of frontal boundary over the Great Lakes and Northeast ... the warmth does reach into the Midwest and East coast for a few days before the cold front sweeps through... followed by a more active stormy pattern with seasonal cold surging back in.

Sometimes you do get some are winter seasons with the patterns definitely repeat and the best example of this that I can think of would Winters of 1993-1994 and 1986 --87. (just using these as examples to show repeating patterns NOT as analogs for this Winter!!!!) For example many of us can recall how severely cold snowy ....and icy 1993 --94 was. However some of you may not recall that winter featured several very distinct up intervals of mild weather followed by the severe cold and the storminess and each one lasted about 9-10 days and it almost reached the point where you or could set a clock by it. And this also occurred in January February of 1986 -87 when the pattern turned stormy air as well.

Lastly I have seen the D10 0z European operationally of course with the big system in the southern stream over th TX / Delta and some cold air place over the Northeast... but this system shows up little way on the 0z 288 hr GFS as well as the 6z... which Could be soemthing tio watch for over the long holiday weekend. And there might even be another system beyond that.

Now none of you should be counting on these events as "likely" or even a reasonable chance event. What these models are showing us though is that IF the pattern does turn cold ver the eastern CONUS --- and this is a big IF!!!! --- we move later into the winter and the Jet stream continues to drop will further south then all this Energy coming in for the Pacific Northwest could end of making up a for several stormy intervals at some point this winter... and that is the critical idea that we should be focusing on here this morning in these extended long-range models in week 2 and week 3

More on the El Nino and Pete /. Repeat Pattern

2006-12-09T12:35:00.000-05:00

15 degress here in North Ashburn VA... two degress colder than IAD and 4 degrees colder than DCA. Does NOT suck

Let me start off with some new information about the current El Nino event. One of the things that Meteorologists should look at to figure out how a particular El Nino or La Nina is developing are the SUB sea surface temp anomalies -- SUB SSTAs.

The reasoning here it is that research has long showed that warming / cooling of SUB sea surface temperatures are good reliable pre-cusors of a developing El Nino or La Nina event. And the recent history shows is to be quite true. For example when the La Nian last winter collapsed in March the cold waters below the surface weakened first before the actual surface water temperature began to warm. Likewise...when the El Niño began to develop in July and August the warming in May & June at the subsurface SSTA again was a precursor to the actual event itself.

This first image is the Sub surface temps from NOV 22 with the numerical values being the temperature anomalies. As you can see there is a large area of very warm water extending across the equatorial Pacific from the dateline almost towards the Peruvian coast... there is a large area of +5c and even large areas of +4c SSTAs.
http://www.wxrisk.com/MODELFOLDERS/today/nov22.jpg

The 2nd image is the DEC 7 map... but we see some noticeable changes in the subsurface SSTA map. First the +5c area is gone from the CENTRAL PACIFIC and the +4c area has shifted to the east and has left the cental equatorial Paicfic ( NINO 4).
http://www.wxrisk.com/MODELFOLDERS/today/dec7.gif

Now what this data should be telling you is that the El Niño may have reached its peak. We'll have to wait another couple weeks to find out if this current trend is in fact the real deal or perhaps it's just a blip. For example it's quite possible that may be a second surgie of warm water developing in the sub-surface levels.... so at this point is still premature to say that the El Niño as reached its peak or that has begun to weakened. But we should know more --alot more in the next 2-3 weeks.

Now if we turn our attention to the overall pattern synoptically... what we have is Pete and his brother Repete. In other words I see the pattern repating over the next 10 to 12 days across most of North America... in a manner similar to what we saw the last 10 days of November. In case you can't quite remember... we saw a deep trough develop over the Western quarter of North America and a very strong Ridge over the Midwest and Southeastern states which bought about a series of very warm days of near record and record warmth. But more importantly keep in mind how the pattern developed in the medium-range.

When I started talking about the developing+PNA around November 16... and other meteorologists began to pick up on it by the 20th or 21st none of us ( myself included) thought that the cold shot that was coming through at the end of the month would last more than 3 days. The medium-range models showed no indication all several arctic HIGHs comign south and it was no indication by any of the medium-range models from NOV 22 NOV 24 Nov 26 at the cold pattern would last 7-9 days. None of the MR showed that!!!

But that is exactly what has happened... and as a result using that pattern I see a distinct repeat of the overall pattern evolution in the next 10 days across North America.

The next map is the operational European from D10... and we can see that the model has a pretty deep trough developed over Western North America.
http://www.wxrisk.com/MODELFOLDERS/today/ec240.gif

And the operational 240 hr 500 MB GFS at 0z ( shown here ) and 6z ( not shown) is very consistent and is a close match to the operational European.
http://www.wxrisk.com/MODELFOLDERS/today/gfs_500_240s.gif

Now again realize that 10 days out I am not forecasting specific storm tracks ot heavy snow areas or temperature boundaries. I am just using these oeprational Models to get an overall general idea of what the pattern is going to look like Dec 18-19. Obviously the strong Ridge over the Southeastern states is very similar to what we saw in the last week of November.

Next I have the 240 hrs 0z GFS ensembles. As you can see ALL members strongly support the idea of a large deep trough over the Western US and many of them show close low over the Southwest states. This are pattern supports a significant winter storm over the great Basin and the lower Rockies and this is a very good agreement for 10 date model ensemble.
http://www.wxrisk.com/MODELFOLDERS/today/f240.gif

By 300 hours out the pattern is beginning to shift but the models this morning dont really shot a cold looking pattern... Eventually the cold front sweeps eastward over the strong Ridge over the Southeastern but by then it has Nothing left and the most of the models show more energy coming in from the Pacific Northwest. Thus when one looks at the operational 0z or 6z GFS... your initial reaction should be OK it cools down little but because more Pacific energy... No Big deal and no sustained cold pattern.
http://www.meteo.psu.edu/~gadomski/ENSHGT_0z/f300.gif

Now while that might be correct again let me emphasize the point I made above which is that back in the period November 20 -25 NONE of the medium-range models showed any hint of prolonged +PNA pattern developing over North America. ALL the the MR Models showed was a very brief shallow short duration cold shot which came through and that is very similar to what the models are showing right now for the period after December 20-22.

For all I know these models may be correct... Perhaps this next cold shot which finally comes through the East around the 20th or 22nd is no big deal... perhaps Pacific pattern continues and we stay mild over the eastern half of the CONUS thru Christmas. But if the pattern does res-assert itself then it looks like the period from DEC 22-30 could turn out to be seasonally cold once again.

The RISE of a New Analog 1957-58???

2006-12-06T12:11:00.000-05:00

No I am not willing to concede in any way shape or form anything regarding this upcoming Winter. In fact the scary or hype headlines notwithstanding I see no reason to hit the panic button that some wish to engage in regarding this winter. It's easy to write headlines which generate a lot of hysteria... whether you are writing headliens lioke " Hurricane Rita to be the worst hurricane to Texas in 100 years".... which of course hit Louisiana... or something like "2006-07 to be the warmest winter ever for CONUS". But there's a price to pay for writing silly headline grabbing Bullshit like that .

It's pretty clear the data this morning that right through December 17 much of the CONUS is going to see temperatures either Above Normal or Much Above Normal. But that is of course after a cold start to the month... so with regard to the overall temperatures over many locations east the Mississippi River by the time we get to say December 18 --20 the monthly temperature anomalies won't be that high.

Of course that really doesn't help if you're in the Plains which are pretty much going to miss out on this next cold blast coming down so they are going start warming up a lot sooner than the areas east of the Mississippi River. On the other hand if one were to take a look at let's say the European ensemble mean day 12-15 you'll see very clear signs that some sort of Ridge is trying to redevelop over western Canada and the model is depicting a broad flat trough over the Great Lakes & Northeast. If that were in fact correct ( which I dont think it will be ) such a pattern would keep the warming out of the northeast quadrant of the conus.

I noticed that the weekly SSTA figure for ENSO 3.4 which came out on Monday generated very little reaction... even though 2 weeks ago it did. Why do you think that's the case? Because two weeks ago we mots of the CONUS east of the Rockies was very warm the surge in SSTAs in enso 3.4 supported those were mongering for the warmest winter of all time. So they took the rise in SSTA and ran with it for all it's worth. Of course the problem is that now they run into the defense which is shutting down the running game big-time... jesus I am now doing football analogies and I am probably sounding like JB....

The defense or the reality here is the fact that the SSTA's last week in this week in Enso 3.4 did NOT rise. DID NOT. In fact the +1.3 C figure for enso 3.4 has held steady now for the last three weeks. Those who continue to argue that the EL Nino is going to stay Moderate or will increase through DEC are essentially are going the analog with one of two late developing El Nino events... the 1991-92 El Nino and the 1994-95 El Nino. And in fact many forecasters had mentioned these two late developing El Niño events as reasonable analogs to what we are saying here in week 2006.

http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ensoyears.shtml

The problem is of course that with this new weekly reading of enso 3.4 s that again show g No rise in the enso 3.4 SSTA means the analog to 1991-92 El Nino is in deep doo doo. It simply is no longer a valid argument to make. The other El Nino analog which has to be look at carefully is the 1994-95 El Nino. In last week of November 1994 the enso 3.4 did reach +1.5c then held steady at 1.4 or 1.3 all the way through December and January and not surprisingly that was a very warm winter... and a below normal snowfall one as well. A strong case can be made that this is similar to we are saying right now but there are TWO problems here .... the SOI and the QBO valuea. In NOV 1994 the 30-day value was almost -7.0 ... and for half of the month it droped to -13.0! However the 30-day average for the SOI for NOV 2006 is approximately -2.0 .

With regard to the QBO the 1994-95 El Nino analog has a serious problem in that the QBO was strongly negative in the Summer and Autumn of 1994 ... which is the exact Opposite of what we are now seeing!!!. Yes I know some forecasters out there dont give the QBO any value but those are the same forecasters who called for 20 named TC this past hurricane season. Failing to learn from that disaster they now hold onto the 1994-95 analog for dear life as they again repeating the same mistakes... ignoring the massive Phase difference between the the QBO values of late 1994 into 1995 and what we are seeing now

Also if we take a look at the latest SUB SURFACE SSTAs in the El Niño regions down to say 100-150 meters it certainly does look very impressive with the large pools of warm water. The first link is the current or latest graph dated November 24
http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_update/sstxz.gif

What's important to note is how the large pool the very warm water are migrating eastward away from ENSO REGION 3.4 and headed towards the coast of Peru. And second the increasing pool of cool SSTA which has developed in the western Pacific just over the international dateline. Again this pool of cooled water has increased dramatically over the last few weeks. The what this data is telling me is that be of El Nino is close to peaking and that those who think the Lower Moderate El Nino is going to continue with no change in strength right to into January (which would greatly increase the chances are seeing a mild winter east of the Rockies) should be very nervous right now.

Lastly lets talk about the new QBO value for November which drop slightly to very close to 10.00. http://www.cdc.noaa.gov/Correlation/qbo.data

As I mentioned in the winter forecast discussion the cycle all a positive QB O phase runs anywhere from 10 to 13 months... from neutral to the zenith back to neutral. AS I said in the Winter forecast the key feature in opinion was going to be what the NOV and DEC 2006 values and whether the drop-off begins in December. I have held all along that the second half of this Winter is when things will get active with regard to snowfall storminess and cold temperatures over the central and eastern US. A drop-off in the QBO into the single digits...say +8 or +6 ... in DEC 2006 would greatly support that view.

However that being said I am noticing a NEW analog which of some folks appear to overlook and I would have to say that i have over looked it this analog as well.

This link is the CPC enso 3.4 values going back to 1950.
http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ensoyears.shtml

Take a look at the year 1957. Just like to Jan 2006 Jan 1957 started out with a weak La Nina... and the El Niño 3.4 that year reached values of 1.5 and 1.6 in DEC 1957 and JAN and FEB 1958.

The match also exists in the MEI values of late 1957 into 1958... where the MEI values held right around +1.0 to +1.14... and this again seems to be similar to what we are saying with the current MEI values

http://www.cdc.noaa.gov/people/klaus.wolter/MEI/table.html

Moreover if you take a look at the QBO values of 1957... into 1958 you'll see something quite remarkable. Note that during the OCT and NOV 1957 the positive QBO values stayed around +10... which is of course is very similar to what we have here in late 2006

http://www.cdc.noaa.gov/Correlation/qbo.data
Note that in early 1958 the QBO did drop to values of +5.35 and Lower.

These very striking matches between what we are saying here in late 2006 and 1957 --58 is current unusual with regard to analogs. We really don't see analog matching like that very often in all three categories. A don't know what it means and this is certainly not in guarantee but I think it'll early at take a panic button and the rise or a near perfect analog of 1957 - 58 which featured a very mild December in 1957 -- really has to be noticed.

OK so DEC 1-8 Cold... DEC 9-15 Mild --What about DEC 15-30?

2006-12-03T16:11:00.000-05:00

The weak area of Low pressure which is developing on the coast of SC / NC is going to develop into a significant Low but well out to see it... which means all that speculation and hype regarding this potential system is going to be unfulfilled. As I mentioned last Friday I was not impressed by this system for number different reasons but the primary ones were that the Upper air patterns over eastern Canada and Greenland are simply not conducive in any way shape or form for the system to develop close enough to the coast so that the precipitation shield to reach the metropolitan areas of the Northeast. Moreover we also have a problem with the Low-level temperatures being simply too warm even if the precipitation were to reach the coast.

As the number of weenies continue to multiply like dust or fungus so will the hype ... which will continue to grow at an exponential rate IF any serious event threatens the Northehast CONUS this winter.

My suspicions and skepticism regarding those few Friday runs of the NAM/ WRF that show the system developing closer to the coast have turned out to be correct. To be sure they were a couple of runs which were trying to show some consistency on Friday so yes I was a little concerned Friday afternoon /evening. But once again the tried-and-true rules have turned out to be correct... that for any sort of significant winter weather threat on the East Coast certain features havr to be in place at 850 500 and 200 MB. And none of these features were place with this system as it approaches the coast. In addition... last Thursday and Friday some these models are showing the actual shortwave developing a negative tilt this evening as it neared the coast but now even that's gone.

There is going to be one more large cold HIGH which comes down Wednesday from Central Canada and reinforces the current Cold air mass. .. if anything for East Coast this one is going to be a more impressive and deeper with the cold because this time around before the front passes... temperatures in the eastern third of the CONUS are not going to be in the 60s and 70s.
By December 8 -- 9 the +PNA pattern ( ridge on west coast of North America trough in the East) begins to break down as several systems from the eastern Pacific slam into the Ridge and rip it apart. There is little doubt that the second week of the December -- say from DEC 9-15 is going to feature milder than normal temperatures across much of the CONUS. The question is how mild? Certainly I see nothing to indicate temperatures as warm as what we saw in November (relative to normal) or the record warm temperatures we saw in January of 2006.

I see the pattern that features a mild Pacific flow but also no strong southeast Ridges. Indeed a pattern last January featured a strong Ridge centered over the Plains states and into the Mississippi valley ... this time around we are seeing according to some of the ensembles several strong systems coming in from the Pacific and re-developing over the Plains and/or Midwest as significant Low pressure areas. To be sure this is not a cold pattern any way shape or form of but the other hand.... with number of systems moving into the Plains and Midwest itsy does not look like the near record warmth we saw in November 2006 and / or January 2006. For the East coast it is Mild pattern and the Midwest wet and mild.

The real issue is going to be what happens after December 15. Do we moved back to another cold pattern or does the mild pattern set up all the way to Christmas / New Years? And this an important question especially IF you are trading this ENERGY wise.

This is the LAST run of the 1 month CAS or soil moisture model... run DEC 2 for the MONTH of DEC 2006. Since eaely NOV ( this climate model is rin once every 2 days !!!) this model for DEC 2006 has showed a clear trend for colder than Normal temps East of the Mississippi river.
http://www.cpc.ncep.noaa.gov/soilmst/img/cas_pt_mon.lead1.gif

Underlying all of this is the complicating psychological factor of this last 2 seasonal CONSENSUS forecasts . It is vital to keep in mind that the seasonal forecast for Hurricane season of 2006 from the consensus point a view sucked as was the Winter forecast in the consensus point a 2005-06. Thus if any portion of the forecast for a mild winter of 2006-07 gets into the "trouble" this could cause a very strong and quick reaction within the energy markets.

If you're going with the consensus and you think Winter2006-07 is a going to be a Mild one obviously what you want is see is NOT a repeat of the first week of the December.... and thus a mild interval from say DEC 9-10 to DEC 27 or so would be great.

If on the other hand you are going against the consensus because that's where the money can be made this year.... since everyone and their Mom believes is going to be a mild winter for most of the US... even a seasonally cold period of DEC 15-30 would have a big impact. This would mean that the month of DEC 2006 featured one week of above normal temperatures (DEC 9-16) versus 3 weeks of seasonal cold.

And IF (this is a BIG IF) the second half the December were to turn even seasonally cold this would be a major defeat for those gambling on a MILD winter and could prove to be very unsettling. It would spark fears that the Consensus Forecast for yet another season could be deep deep trouble.

12Z NAM fantasy; No thanks I wont Bite ; Review of my Midwest snowstorm forecast 11/29

2006-12-01T15:16:00.000-05:00

Taking a look at the Midwest Big snowstorm... my prediction made Wed afternoon 243 pm EST.... "12z WED models support the Big Midwest Low/ snow WHAT ABOIUT 1ST SECS 12/4-5???" .... said this

6'' seem likely could be more ( up to 12 inches) but for one its warm now and transitioning to cold and the ground will be wet.... Big winners QUINCY ILL along with GALESBURG ILL JACKSONSVILLE ILL PEORIA ILL into DeKALB JOILET and maybe Chicago

I do aplogize to my Midwest fans who wnated to see my snowstorms maps broken out for this event. if I had the time I would of m,ap some maps in the 3 tier systems that I have nbeen usiong since 1999...2000.... 1st guess 1st call Last call

Well be 12z FRI NAM has an interesting solution for Monday recording the possible development of a coastal low over eastern NC and of course seeing this development causes a reaction by some within the meteorological community.

While it is true that the 12z NAM develops this wave of Low-pressure significantly closer to the coast so that it actually produces precipitation from eastern Virginia up into New York City coastal New Jersey Long Island and southern New England on Monday... there are some serious problems with this scenario and these problems are more than sufficient to cause me to look at the fantasy of 12 z NAM solution as well just that... a fantasy.

To be sure this trough is neutrally tilted by the time and reaches the Mississippi River and appears to develop or take on a slightly native tilt by Monday morning as it moves through the Tennessee Valley and the Appalachians. This shift in the trough axis from neutral along the Mississippi River to negatively tilted but time it reaches the Tennessee and the Appalachian Mountains IS ideal for coastal development.

The problem here is that s/w which appears to be fairly strong and swings through the Midwest on Sunday has no reason to slow down. There is no upstream blocking features such as a - NAO or 50/50 Low. Keep in mind as you look at this map you can see a strong Jet streak that is up stream which is associated with this Midwest trough as it reaches the Mississippi river
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/nam/12/fp1_060.shtml

An addition the NAM/ WRF past 60 of hours is notoriously are unreliable... and any solution that the model is producing past 60 hours must be compared to other more liable models especially in the early stages of the medium-range. In this way one can do a check to see if the NAM/ WRF 66 to 84 hours solution is not bogus.

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/nam/12/fp1_072.shtml

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/nam/12/fp1_078.shtml

And of course when we do that we find that there is no other model development which supports the operational 12z NAM. Sure the 12z GFS is a little closer to the coast and shows a bit more development but again this is because we are within the 72-hour time frame . Given how fast the system is moving and how there is no reason for to slow down I cannot find any stenotic lesions as to why he 12z NAM would have such heavy VVs over the coastal Plains of the Northeast-- from eastern VA to southern NJ to NYC the southeastern New England.
And lastly if arguendo the 12z Friday NAM solution is liable then there is the problem of Low level temperatures of which does not support all snow or barely supports a mixed event .
As for the next event December 8 -- 9 there is not much hope left this one either.
As for how long the warm interval is going to last... who knows? One thing that I do now is that the temperatures will not be as warm as what we saw in NOV. The operational European Canadian and GFS as well as those ensembles all show a seasonally mild pattern with a flat Ridge over the Southwest states and good Pacific jet slamming into northern California north to Br Columbia... and some sort weak shallow troughing over the Great Lakes and New England. Again this is a mild pattern with a lot of Pacific air but not the record or near record warmth we have seen for NOV 2006.

Interestingly the 12z GFS for DEC 17--- 372 hrs is fairly cold with some sort a significant trough developing over the central and eastern US and several other members showing a+ PNA redeveloping.
http://www.meteo.psu.edu/~gadomski/ENSHGT_12z/f372.gif

c000 p001 p002 p003 p004 p0005 p008 p009 p010

" DEFLECTORS just snapped on Kep' tin..." as 12z GFS jumps in bed with 0z ECMWF

2006-11-30T11:56:00.000-05:00

Well the move is now done and over with... but it's not been a loss of just the last three days. The actual time spent in searching for new place and all the other things that one must do when making a major relocation like this... is a lot mo than three days . I ended up losing a lot of free time for the month November. This is free time which I planned to use to for some special projects including a complete revamping of the snowstorm checklist. Now that things to settle down little bit I will have to bust some serious fanny to get the checklist up ands running with a snow event possibly looming on the East Coast with the first significant to storm December 7 -- 8.

The first image I'm presenting is an approximate representation of the 204 hour 0z ECMWF. I made this this map from my copy of the 204 hr with my Microsoft image composer. As you can see them all clearly shows very strong shortwave move into the Tennessee Valley and significant call their damning. Note that the 1044 arctic HIGH we see in the western portions of the Upper Plains at day 6-7 ... has extended a "neck" into the Great Lakes & New England as this system approaches the East Coast. The signature is very clear for CAD.
http://www.wxrisk.com/MODELFOLDERS/today/bgh1.jpg

These next two maps are from the 12z Thursday GFS. This image shows the 500 MB shortwave move into the Tennessee Valley and then across the middle Atlantic states at 180... 192... and 204 hrs. Note that the shortwave is positively tilted but does turn to Neutral tilt at the coast and that the Vort Max travels in a due West East direction across the state of Virginia. It does not turn to the northeast and of course neither does the 850 low or the surface Low. The reason for this is that the midday GFS sees another system upstream which is acting as a Kicker forcing this system to slide East off the coast.
http://www.wxrisk.com/MODELFOLDERS/today/COMP.jpg

Next image is the 850 Low track with the RED dot the approximate position of 850 low. And as you can see this is a great track for Northern Virginia Maryland Southern Pennsylvania New Jersey and perhaps as far north as New York City and Southern Long Island but that's assuming that it stays cold at all levels of atmosphere. Again note how the model does not turn the system up the coast but essentially tracks it off in a due easterly direction.
http://www.wxrisk.com/MODELFOLDERS/today/COMP1.jpg

Now I'm not saying that the midday Thursday GFS is correct that simply with the model showing.

That being said there are some things to talk about. First the arctic HIGH that comes down from western Canada into the Plains and Midwest is an impressive 10044 MB HIGH The climo of significant or major East Coast snowstorms is such that large arctic High pressure systems such as the one we are going to see tend to favor East Coast Low-pressure development. Second the reason why we do not keep cold air in place is because of the unfavorable pattern we have 500 mb over eastern Canada and Greenland. This is a textbook case for all you out there to understand why the upper air patterns over North America are so vital keeping a ALL snow event the Northeast corner. In this case we don't have the features that we want to see typically look with all snow event. According to the model and again this is just the best early guess ... there is no 50/ 50 low over or near Newfoundland Canada. There is no high Lat blocking over Northeastern Canada or Greenland.

Because of this lack unfavorable upper-level pattern over eastern Canada and Greenland to large arctic High and its neck that extends into England breaks down as the secondary Low develops on the Northeast coast of North Carolina. This allows a southeast wind to develop until the coastal Low finally kicks and thus the changeover to rain along the I-95 Corridor from Richmond all the way to NYC.

Now all this means is that the odds are not favorable for an all snow event for the I-95 big cities but it's quite possible that is this set up that the big cities could see significant snow before changes over and given the fact as early December one should not look a gifted worsen the mouth.

update coming at 11am Yes D8-9 0z Euro shows MECS THEN pattern collapses

2006-11-30T09:50:00.000-05:00

Hello from N ashburn VA... just 4 .25 miles from Lessburg airport ... yes folks I have seen the op 0z Thurs ecmwf and its MECL-- miller B ( major east coast low) which for some could be a snowstorm especially over interior N Mid Atlantic and New England... whatbis very impressive is the 1044 MB high that Necks east of the Great lakes and gives off clear CCAD signature ..

more later getting caught up with paying clients... i saw yesterday that one of my competitors in Happy Valley PA... wich was pushign the New Orelans Nantucket track from 11/26 FINALLY gave up on the siliness ... of course to over compensate for this busted frorecast and wish coast he then went extreme the OTHER way... calling the Midwest Low now developing over ARK will be one of the biggest if not the biggest pre xmas Midwest snowstorms ever..

NOT....

southside chicagao will see best snow as well as SW chicago over towards La Salle and Quincy and St Louis... wet ground and warm temps do not make for HUGE massive snowstorm totals.... i saw one weenie over at eastern issue a professional map calling for a stripe of like 10-20 inches for Chicago... Come on folks Get a fooking clue

after the dec 8 -9 event the +Pna will breakdown.... for a while.

12z WED models support the Big Midwest Low/ snow WHAT ABOIUT 1ST SECS 12/4-5???

2006-11-29T11:43:00.000-05:00

busy moving in today...but 12z NAM and GFS bomb STL MO western ILL and ORD with good heavy snows.... and makes me look good

6'' seem likely could be more ( up to 12 inches) but for one its warm now and transitioning to cold and the ground will be wet.... Big winners QUINCY ILL along with GALESBURG ILL JACKSONSVILLE ILL PEORIA ILL into DeKALB JOILET and maybe Chicago

12z GFS show arctic blast #2 much like the 0Z ecmwf did at DEC 6-7
NOTE THE 1044 HIGH

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/images/gfs_slp_096l.gif

THE 12Z AT 120 hrs shows wave development off NC coast... model might be too flat so it could be closet and does bare watching

lastly yes thanks for all the great comments about this blog.... as to the question why couldnt I be like this at eastern?

two reasons one I am not trolled here.... so I dont have anything to respond TO.... and second maybe the question should be why couldnt eastern be more lke this blog with respect to me?

6z GFS is CRAP; Its a true Midwest Chicago snowstorm + PNA looks to hold

2006-11-28T08:14:00.000-05:00

not much time today.... first off the 00z ECMWF and GFS are in GREAT agreement on signfificant Midwest snowstorm coming with central and Northern ILL into estern MI seeing 6 or more inches of snow this weekend but the 6z GFS takes it all away.

lets be clear before some of you east coast or bust assholes cackle with villaneous glee -- the 6z GFS is bullshit and anyine with a brain can see it. The GFS says there is NO huge ridge over SE`coast. The 6z GFS model says in 60 hrs that ridge will be gone....

so I am going to hit 70 today and wed b/c of what then? The Klingons firing theot warp engines? The one thing we do KNOW about the next 3-4 days is that the SE ridge is strong and a fghter which means the s/w over TX / eastern OK and or the western Delta will be forced to travel NE along the and over the Ridge as the ridge slowly slies east.

This is a TEXT book case of why a NEGATIVE NAO is sooooooo important in he set up for a SECS/ HECS / MECS

look at the over whelming data

84 hr 500 MB 0z GFS
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/00/images/gfs_500_084s.gif
72-96 hrs 0z ukmet
http://meteocentre.com/models/ukmet_amer_00/ukmet_00_panel.gif

72-96 hr ecmwf
http://meteocentre.com/models/ecmwf_amer_00/cep00_9panel.gif

and the ENSEMBLES at 84 hrs almost every one of them have intense closed 500 Low over far eastern MO or downstate ILL or IND.... pay attention to C000 P001 P002 P003 P005 P006 P007 P008 AND P10

versus this BS....

84 hr 500 mb 6z GFS
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/06/images/gfs_500_084s.gif

ITS NOT EVEN CLOSE ... The 6z GFS is a Bogus run....

lastly remeeber all those pronouncement ( i was readings some of the older posts ver the weel at eastern) on how this cold blast in early DEC is NOT going to last and the Pacific Jet would break through and how dec would be mild?

they dont look too good right do they?

If you get the eastern Pacifc and Pac NW wrong you got NOTHING!!!...

2006-11-27T16:08:00.000-05:00

I cannot spend as much time posting on the medium and long-range forecasts as I wish to as the next two- three days because I am in transit and moving the up to Northern Virginia. So the posts will kinda be a short side of... but I still should be able to cover all the major points.

One of things that you will notice in this web site and on this blog is that I try not to favor anyone particular region of the country. I do this for number reasons but one of the fundamental principles that I was taught early on as an undergrad was that If you cannot forecasts the Pacific Northwest & western Canada correctly thing you've got nothing. You got Bupkis... and any medium-range forecasts that you make in going to up in the crapper.

A classic example of this is the current pattern change which is going to occur this week across the Conus. Back on November 15 --16 when I started banging the drum about this probability of some sort of pattern change and then later on a significant pattern change ... I THINK I was the only doing so at THAT time ( but I might be wrong about that) . I do know that my early call of this possibility was greeted by a great deal skepticism in the usual weather forums. The reason I think this is not because it's DT.... since I had a reputation for NOT jump the gun and NOT gong for the hype... until I feel there is considerable amount of evidence... but because a lot of forecasters had misread what was going on Eastern Pacific.

This is a repeat in some ways of what went on Last winter. I am sure I don't have to remind you that the consensus forecast from a lot of well-known private forecast services was for a cold and stormy winter 2005-06 over the eastern US. There is very low emphasis outside of my self from any other forecaster that I know about the power of the Pacific Jet last winter enhanced by a persistently Postive EPO and the very neg QBO. IMO this is why most of the winter forecasts for a cold and /or stormy eastern US busted so badly.

This time around they seem to be this general except in said the Pacific Janet El Nino enahnced was gone keep on firing right to most of December and not really let up until either the middle portion of December or perhaps until after the holidays. Well if that is your assumption then you may be about to lose the game so let me buzz you out ... and say thanks for playing Johnny can you tell us what he's won as a consolation prize!?.....

The 0z and 12z data are very strong both the operational and the ensembles in showing that the +PNA is going to last through the first week of December may be to December 10-11... then after that who knows?? . Perhaps you don't know but let me remind you that the important SSTA in ENSO region 3.4 did NOT rise today...it held at +1.3c. If the El Nino is moving towards a moderate ENSO event if only for a few weeks... the idea that we can now turn cold across North America especially east to the Rockies for a 7-10 day period is VERY significant.

If we take a closer look at some of the details here... there is little doubt my mind now that the significant Low which develops over the Eastern US on December 1-- an event which I started talking about back on November 16-- is going to be a Midwest snowstorm. In particular the 12z GFS UKMET and ECMWF all show this wave developing from the Delta tracking NE towards southeast Ohio and perhaps up near Erie PA or western York state... although the midday European takes it will further west... very close to Detroit. Given again the Autumn pattern -- see my winter forecast -- that has already seen 4 or 5 significant Midwest Lows this sort of track really should NOT be a point of controversy.

Of course the usual sources of hype are trying to insist that somehow this pattern COULD possibly shift this Low towards East Coast blah blah blah. But don't you fall for that BS. In this ... moving from an extremely warm pattrern with the huge Ridge in the southeast towards a +PNA and + NAO... well you can say with a great deal of confidence that this is not an East coast track or even a inland East Coast threat.

Both 12z runs of the operational European and GFS at midday are very impressive with the 2nd Arctic air mass which comes down from western Canada into the Plains & Midwest... and to lessor degree into the East Coast.

Let me emphasize again one other point... which is a really important one not only for those who are trying to practice and learn synoptic meteorology but also those who are trying to trade energy markets. As I stated in the Winter forecast... In a week to moderate El Niño pattern the GFS in particular has a heavy bias to constantly breaking down any sort of cold pattern in the 11-15 day and the developing some sort trough on the West Coast. Sometimes this is going to be the correct way to go but a lot of times the operational GFS is going to be the outlier even against its own ensembles. This is going to result in a lot of folks killing the cold pattern prematurely and going to blow torch for the Week 2 forecast. ......"Oh sure it's going to cold for a few days but next week...man Look at that blowtorch... "

folks who make that sort of flippant and shallow remark really don't have a clue what the hell they are talking about.

The case in point is this current cold shot coming up in the 6-10 day. If you recall the 6-10 day from last week as well as the 11-15 day from last week... from the various private weather services as well as CPC... NONE had cold in the Eastern US. None .... why ? Because the operational GFS screwed up the Eastern Pacific and especially many the ensembles continued to show constant Pacific flow. Then as we got closer to D10 the pattern began to look like colder and more sustain cold. This is going to be a problem all winter especially the first half of season. Let this be a lesson to you and don't forget this Model tendency and you will do all right the rest of season.

The +PNA cometh !!!!

2006-11-26T11:25:00.000-05:00

Looking at the data in the overnight hours and early this morning it appears that I have become a WEATHER GOD. OK.... OK..... I don't really mean that but what I am trying to drive home is the idea that the significant pattern change I have been banging on at the end of the month is real . I think its clear to all now that from looking at all the data that not only is this warm pattern about to come to an end but there is increasing amount of data that shows were moving into a +PNA.

To be sure when I first post to this idea back over Nov 15 - 16 it was greated with a lot of shall we say "Negative" comments and feedback at some of the weather forums where I occasionally post. Well I don't think those folks still hold the same view!!!!!... and if they do they probably should well get out of weather business and go sell some shoes.

There is of course debate as to how long the +PNA is going to last or If the +PNA is going to be a split flow... with the southern branch coming into say California and the northern branch showing the Ridging over western Canada. But again it's time to face reality... Winter is coming so enjoy this spectacular weather while you can.

the 0z Sunday GFS at 132 and 144 hrs showed one of the most impressive cold fronts I have seen a longtime. The 850 temps at 132 hrs -- the morning of 12/1-- RIC +13C DCA +12 NYC +11 BOS +10 ALB +9... yet 12 hours later RIC drops to -3c DCA-9c NYC -8c BOS -6c and ALB -9c
http://weather.unisys.com/gfsx/5e/gfsx_850_5e.html
http://weather.unisys.com/gfsx/6d/gfsx_850_6d.html

Bloody hell... now that's a cold front!!

The other issue of concern I have expressed many times here as well as some other places is that some sort will wave of Low pressure is going to develop on the front as the southern end of it comes slows down significantly DEC 1.

The 0z Euro show this wave developing over the TN valley and bringing a early-season snowstorm to portions of the Midwest and this is now supported by the 6z GFS. Recall the rule I mentioned in a previous posting here that whenever the 6z GFS and 0z Euro agree it is always a good sign that the 0z Euro run is correct. Of course such a wave of Low pressure would delay the Arctic front at least another 12 hours until it passes through the East Coast.
http://www.meteo.psu.edu/~gadomski/ECMWF_0z/f120.gif
http://www.meteo.psu.edu/~gadomski/ECMWF_0z/f144.gif
http://www.meteo.psu.edu/~gadomski/ECMWF_0z/f168.gif

6z GFS 500 MB
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/06/images/gfs_500_132m.gif
surface map
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/06/images/gfs_slp_132m.gif

Here is the mean pattern taken from the Penn State e-wall site for Day 8-10 at 500 MB... for the 0z operational ECMWF and the 0z GFS. Again we can see clear indications on a full power classic +PNA. Of course the 0Z GFS-- map on the right side -- is not THAT impressive because it closes off a Low at 500 MB over the southwest US but as I already stated the 6z GFS does not show this feature and is very close to the operational European..
http://www.meteo.psu.edu/~gadomski/ECMWF_0z/hgtcomp.html

In addition you can see this for yourself by taking a look at the ensembles runs of the 0z GFS. As you can see a few members to hang back a LITTLE piece of energy or bend in the Jet stream over the southwest states but NONE ( not one!!!) of the 11 members show closed off Low over the SW states. Therefore the data is overwhelming that idea of the closed 500 Low over the southwest US as depicted by the 0z GFS to be BS.
http://www.meteo.psu.edu/~gadomski/ENSHGT_0z/f240.html

We can also see that by taking a look at the 240 hr Canadian and GFS ensembles Mean maps. The map in the upper left corner shows the operational GFS and again note the closed 500 Low over the southwest. However the bottom left map which is the GFS ensembles mean at day 10 clearly shows a classic +PNA as does the 0z CMC ensembles mean ( bottom right).
http://www.meteo.psu.edu/~gadomski/NAEFSHGT_0z/f240.gif

Again let me emphasized that I am not forecasting the coldest air mass of all time or anything close to historic levels or even SIGNIFICANT cold oubreak (yet) . My point is that the pattern shifting and showing signs moving into a early December 1 run of the mill Winter pattern. To be sure there is no reason to start running specials on the god awful Weather Channel (one day I have have a post about TWC and what a wretched place that has become) just yet but in my opinion any time a Winter pattern develops in El Niño year is always a good sign since there been many El Niño Winters where thehre has never been a sustained Winter pattern that has locked in place. Of course I don't know if the new pattern is going to "lock in" or last seven days and then collapse.

A case can be made for either scenario at this point I just don't know but it's nice to see this pattern developed if you are Winter lover as opposed to what we have seen for much of NOV.

DONT LOOK AT DAY 8 WHATEVER YOU DO!!! -- LOL....

2006-11-24T11:54:00.000-05:00

Well that was a pretty good Thanksgiving and I dont telling you I thoroughly enjoyed the Noreaster... along with the usual traditional dinner. This of course is the last Thanksgiving on I am going to be spending here in Chesterfield Virginia. This house has a lot of meaning for me ... my son was born in this house... grew up through Toddler hood and now as a 9 year old and in this house I started this business and web site here in the basement which is my home office. And while the new location surely is nicer it takes a while for it becomes home... but isn't that always the case when you move?

Before I get into the actual forecasting here this morning I wanted to make a couple of brief comments. First in my little humorous blurb I made in the previous posting about having the wrong attitude with regard to altering a forecast... I may have stepped on a few toes accidentally. There are a lot of meteorologists in the private sector who have that mentality of not changing the forecast until actually busts. It is not just a NWS mentality. In fact I know a lot of forecasters in and of US who do change the forecast when it is needed especially is the short-range. Really all I was attempting to do to make the a point was taking it to the Nth degree. No offense intended.

Second... there seems to be this perception out there that regarding the debate on how warm the winter it is or is not going to be ... and that it is aimed at one particular person or perhaps just a few people. Well that really isn't so. There are a lot of private forecasters both on their own and within Energy and at the Agricultural companies which are forecasting a pretty mild winter. The forecasters over at Sempra trading and Telsa forecasting and some folks over at Citadel... are all in the warm winter boast ( just to name a few). This friendly discussion and debate is not really aimed at any one particular person. For me it is an intellectual exercise to see if the techniques and ideas which I've used over the last several winters actually has a some sort of validity or perhaps that I am just lucky and I'm really just full of Bravo Sierra.
OK let's move on to the weather. As many of you know I've been forecasting a pattern change to occur at the month into early December (since Mid NOV) as well as the potential for some sort of significant event over the eastern US. Not necessarily an East Coast event but some sort of significant low as a possibility on 11/20- 12/1. Of course it might be more likely send the second but that's the general idea.

In case you did not see the European model over the last couple of runs I am presenting the date 10 European from 0z Thurday then 12z Thurs and 00z Friday.

http://wxrisk.com/MODELFOLDERS/today/NOV24/0Znov23D10.gif

http://wxrisk.com/MODELFOLDERS/today/NOV24/12zNov23D10.gif

http://wxrisk.com/MODELFOLDERS/today/NOV24/0Znov24D10.gif

As you can see each warm the solutions are significantly different from the other... with the first map being the coldest. I am not really forecasting some sort of bitter arctic outbreak percentage or the coldest air mass in several years or anything like that. My whole argument here is that the pattern which is dominated Noth America for November... which has featured a deep Vortex over the eastern Gulf of Alaska near the British Columbia / Alaska Panhandle Coast... is going to break down and this result in a more seasonal early December pattern. Not historic cold... Not severe cold... Not exceptional cold just seasonal. Even though there is a wide variety of solutions on many of these medium-range models by date 10 which is to be expected in aweak El Nino pattern the one thing that we can see is that very few of the models or in some old members are still showing a deep for tax in the Eastern Gulf Alaska. Some depict a strong+PNA... some a weak +PNA... some with a split flow. But from what I can see very few if any are still showing the powerful Vortex on or just off the West Coast Canada by DEC 1

Of course with all the energy initially going into the Rockies & the Great Basin... the Ridge over the eastern third of US is going to strengthen dramatically and I would not be surprised if Chicago got close to 70° Tuesday afternoon. Interestingly although the Ridge over the SE states looks very strong the actual cold front does not really slow down and makes pretty steady progress day 5-6-7.

Of course the overnight European model at D7-8 as well as the 0z GFS and 6z GFS are trying to develop some sort of coastal low on the front. Given the matter of cold air which is going to be pouring in rapidly behind this front and the fact that that the front might stall just after it clears the East coast the development of this coastal Low is a very interesting feature indeed.

http://wxrisk.com/MODELFOLDERS/today/NOV24/12zNov24D7.gif

http://wxrisk.com/MODELFOLDERS/today/NOV24/12zNov24D8.gif

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/00/fp0_192.shtml

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/06/fp0_192.shtml

If this was the middle of Winter there would be a lot of snow talk going around the various when the communities for next DEC 2. To be sure given the fact that the seasonal trend has supported so many coastal Low pressure areas this season it would be foolish to completely dismiss the idea of a coastal Low developing on the base of the trough December 1-2. It is early but I am not going to dismiss the idea and there is some support from the various GFS ensembles for this sort of scenario as well. The problem is of course that the cold air has be in place as soons as the front passes... it still eight days out ... and an awful lot can go wrong. It is not an ideal pattern for any sort of winter threat for the East Coast... and everything past fall in place just exactly right for something like us to occur.

By D10 you can see many of ensembles are showing some activity with respect to strong short waves of dropping through the Gulf Alaska headed towards British Columbia / Pacific Northwest there are no members that show a deep vortex STILL situated in the Gulf Alaska. None.

http://wxrisk.com/MODELFOLDERS/today/NOV24/f240.gif

http://wxrisk.com/MODELFOLDERS/today/NOV24/gz.1124.240.gif

By 288 hrs 12/6 things look a lot more interesting. C001 which is the Operational 0z GFS looks pretty benign when you compare it to some of the other members such as C000 (wow) p001 p003 p004 p008 p009 p010 and P011 (wow). This is not enough support from the various ensembles in my opinion to get "excited" about some possible event on December 6 but it is something to look at.
http://wxrisk.com/MODELFOLDERS/today/NOV24/f288.gif

WED AFTERNOON COMMENTS

2006-11-22T17:45:00.000-05:00

While the e-mail is flowing fast and furious as more and more folks realize that this blog will be updated regualrly and it gets out there into the meteorological and weather hobbyist communities.

I am in the mist of a major overhaul of the snowstorm checklist and when it is done-- I hope by around December 1-- it should be the most comprehensive and arguably enjoyable thing for snowstorm lovers in the Northeast US to go to a regular basis during the cold season months. By the time is all said and done it will stun you with its comprehensiveness and I hope its ease-of-use. It's something I have always wanted to do but never had the time but now is the business doing so well I can cut back on some are other activities and make this snowstorm checklist the thing of beauty I've always wanted it to become.

As far as the midday stuff goes obviously the midday GFS has come about with a totally different solution than what the last several runs were showing with regard to the pattern shifting next week and the development of the deep trough over the East Coast. I don't consider the this 12a GFS run to be a viable solution as it has a far too much energy in the southwest US where it develops that huge upper Low over the Great Plains and Rockies which results in that blizzard that moves into the Upper Plains. Of course with that huge trough over the Rockies the Ridge over the Midwest becomes very strong... and the cold front is delayed significantly. But the time it reaches the East Coast the trough is a shadow but what they model was showing at6z and 0z .... as a result the cold air is essentially gone.

The midday European has a similar solution but not quite as extreme... and when the trough does reach the East Coast its still has a fairly strong amplitude with it and there is still quite of cold air. In fact the operational European stalls the front in a SSW to NNE alignment from Georgia to Cape Cod day 9.5 and day 10 with a very impressive temperature gradient over the middle Atlantic states....

The GFS ensembles on this Wednesday afternoon are not supportive of the operational run and have a lot more amplitude in the eastern trough at D8-9

Interestingly by D9-10 the 2z operational European shows the Pacific jet has split up into THREE distinct branches along the West Coast in North America. I will put this map up on the Modeltracker page later. IF that is correct and I don't know that it... then the patetrn COULD hold some promise for December across the central and eastern US with regard to seeing at least normal temperatures and still quite a storminess. You see when you have the Jet split put up into 2 or 3 branches they no longer have a uniform flow and it is easier to get the northern branch to buckle or amplify while the southern branch continues to bring in these significant systems from the Pacific. I'm not forecasting such a positive winter scenario development to occur I just think the D9-10 operational European has some promise. That's all just a promise no guarantees.

ANOTHER noreaster!!! what does it Mean ??? .

2006-11-22T09:39:00.000-05:00

gobble fooking Gooble ya sick twisted freaks....

I have gotten some emails and coments about how often this Blog with be updated... Good question..once I get settled in to the new place and shift over to my early hours-- where I am up at 530 or 6am I hope to have this Blog updated every days... sometimes Twice a day if the 12z stuff is worthy. In that instance I will do so AFTER the 12z GFS CMC UKMET and Euro have all come out.

Also I will have to figure out what to do with the Modeltracker page as well now that I am running this blog.

The next thing I want to talk about is this perception I see from a lot of undergrad and it exists even in some professional meteorologists that when they issue a forecast .... be it short range... medium-range or long-range or seasonal forecast... that is wrong or somehow the demeaning to change the forecast. OK lets get right ot it... That mindest is crap and if that is your perception as a meteorologist you going to fail in the PRIVATE sector. With that sort attitude / mentality you will probably in the National Weather Service... possibly as a large fat overweight govt employee with your arms sticking out of the sides at a 45° angle still working the Midnight shift at the age of 55 ...when one day your wife tells you she cant take it anymore and is leaving you for the entire Washington Redskins football team and you end up getting a heart attack!!!!

Forecasting is about getting a forecast RIGHT --- it is not about your ego. If you make the forecast and you can see itis busting change the damn thing!!! This is the way it is ( and has to be ) in the private sector and quite frankly it's this attitude that some undergrads and other professional meteorologists (even in the TV business) which cause a lot of tension between meteorologists who deal with the energy and agricultural markets and those who have this weird perception or mindset. I have demonstrated many times on my web site (and other locations) that when I think MY forecast that I originally issued is wrong... I change it. It's a tricky thing to be sure because you don't like change it too early but when it becomes obvious the fastball is about to smack in you face please get bail out... Thank you... this has been a public service annoucment from DT ( aka the Master of Disaster the Commander of Choas ...the Virginia Vigilannte)

I presume by now you have heard or read about the snow which was reported in portions of Georgia & SC yesterday and I have heard but not yet confirmed that there was the snow reported near the GA FL state line. Yesterday afternoon around 3-4 PM hear in the Richmond metro area I personally saw rain mixed with snow which was a pleasant surprise and the temperature was 41 or 42°.

I have emphasized this point several times at some of other forums where I occassionally make weather comments but I have to emphasize it one more time. This is the sixth significant and fourth major coastal LOW we have seen on the East Coast since October 1. Seasonal patterns matter. A lot... sometme the entire seasonal forecasts can be easily detected and picked up on very early and good forecasters can see it. We may be seeing this sort of thing unfold right in front of us. What's amazing about this stormy pattern for the East Coast.... is that we have had these coastal storms when the pattern has been cold in October and mild November. The point is it does NOT make a difference -- you fart too loud in this cold season you are going to get a big storm on East Coast. In case you did not know for central VA Autumn 2006 is now the Wettest Autumn ever and that is exceeding the 1999 season we had Floyd.... and I suspect that when I browse the data I will find similar sorts of records or near record set in many locations across Virginia and North Carolina and probably Maryland as well.

I suppose it's possible the seasonal pattern may break down as soon as we move into winter... I know when I was in undergrad and I was looking at the trend in the autumn of 1987 and looking forward to the Winter 87 --88 we had a lot of Noreasters in October and early November on the East Coast but when the Winter hit pattern collapsed. But I don't think that will happened as we now into late November.

Of course that being said there's no guarantee that we willl see snow as opposed to rain especially IF the pattern stays mild. Of course based on my WINTER forecast that is NOT going to happen but it's a forecast ... I mean just because I issued that seasonal forecast does NOT mean it is going to be correct.

This morning I have a lot of winds here in eastern Virginia up to 50 miles an hour .... and if you get the chance you may wish to take a look at the radar from last night...
http://www.wxrisk.com/MODELFOLDERS/today/latest.gif

also here is the latest surface map this morning.
http://www.wxrisk.com/MODELFOLDERS/today/SFC_NORTHEAST.gif

Again I wanna make a point that I made several days ago when everybody else was talking about how warm it's going to get into the Northeast .... that this coastal storm and its North winds would keep temperatures colder than what the pattern would otherwise suggest in the upper atmosphere. To be sure once this Noreaster is gone the warmth over the Plains / Mdiwest will surge eastward ... but it is delayed because of this coastal Low --- of that there is no doubt about it .

Taking look at the some of the DEC early forecasts there is quite a bit of dispute as to how December is going to appear. The NOV 1986 temps over the CONUS is almots an identical match to what we have seen here in NOV 2006...as the forecasters at EarthSat pointed out yesterday. I know there are some forecasts which call for armer than normal DEC but I don't agree. For those if you wish to consider such things here is a link to the latest December forecast from the CAS model...
http://www.cpc.ncep.noaa.gov/soilmst/img/cas_pt_mon.lead1.gif

and as you can see for next month it has a decent cold east of the Mississippi River. I mention this because last year we had a cold November and December and the CAS model from five months out consistently forecasted significant cold temperatures in December over the eastern third of the US.

Taking look the medium-range model the operational 0Z GFS at day 9 and 10 show this massive trough over the eastern third of the CONUS whoile would seem over done. But keep in mind we might be in phase 4 MJO by then shwich does suport a stroing brief amplification over the Eastern US. As a general rule when the 6z GFS and the 0z ECMWF are in close agreement especially at the 500 MB level... that leads me to have much bigger faith ( than I would otherwise) in the 6z GFS OR the 0z Euro.... but that is not the case thing this morning.

The euro hangs a lot of energy bang in the SW so the bottom of the trough beaks apart. Is the euro right or is that model showwng its characteristic bias with western US trough in digging Too much energy too far south? The euro ens says yes the op euro is hanging too much energy back in the sw at day 7-8 and 9. Still as many of you know I have been calling for a posisble significant event SOMEWHERE over the Eastern third of the of the CONUS 11/30 -12/1. I dont know IF the coastal Low that might develop b/c of the east coast trough ( as shown by the 00z and 6z GFS) is the event or not. It may just be this cold trough and blast of arcti air coming in.... and the Low may develop well off the coast.... keep in mind I first made that call last weekend -- NOV 11-12 . That being said I sort of like the way this is looking right now... But I am NOT in anyway declaring victory...

ENSO 3.4 rises Finally to +1.3 C -- winter canceled

2006-11-20T14:54:00.000-05:00

pay attention here... if I forecasted a SECS/ MECS or HECS every week for 4 or 5 straight weeks and I was wrong every week.... and then I finally ht one.. would I get any credit for forecasting ?

God almighty I hope to hell not. Yet this is exactly what we are seeing WRT the weekly ENSO region 3.4 SSTAs that came out late this morning and FINALLY reached +1.3c

Big fooking deal.

Keep in mind folks the very same warm mongerers that backed in July an August that were speculating about a Strong El Nino... who have since backed away from that BS... have been predicting that Enso region 3.4 rsing to +1.3c for the past 6 weeks. One guy a met student a Millersville U in PA has been saying enso would rise to 1.3 every week since Mid OCT -- his posts on this can be seen over at DBM or eastern..

That fine. Forecasting mean sometimes you will be wrong. But despite the fact that every week his calls have been wrong ... when the enso 3.4 finally does reach +1.3 for 1 week... it should not be viewed as big deal

Moderate El Nino events dont bring 90 degree temps to Calif -- it rains there. Moderate El nino events do NOT prodcue droughts in the Plains.... all you have to do is look at the standard boiler plate from TWC or CPC on the winter effects of moderate and strong El Nino event to see this. Clearly we are NOT in a pattern anything clsoe to a moderate El Nino.

El Nino does NOT suddenly appear or kick in when the enso 3.4 reaches +1.3c. El Nino is a dynamical process . IF and when the Enso 3.4 rises and holds to +1.3 or say +1.5 for say 4 weeks AND we seee a classic Moderate El Nino pattern over North America THEN we will see.

The 0z Euro gaian was strong with the pattern amplification. For those follow the Phase of the MJO... in 10 days or so we will be movng into phase 4 which DOES support some amplification ... one that does NOT last mind one but we will have to see about that .

the 12z Euro and Gfs show My POSSIBLE signiicant eastern US Low -- SEUL for 11/.30 12/1. The 12z GFS is fooking whacko after day 10 and way over done but even the 12z Monday day 9 9.5 and day 10 operational European shows a classic Miller B Midwest Low jumping to the LI coast set up.

MY WINTER FORECAST 2006 -07

2006-11-19T16:21:00.000-05:00

Well it is done... I have posted my WINTER FORECAST 2006-07 ... a bit Later than usually but any FINAL winter forecast issued before NOV 1 is crap and has no basis in science. Note the key word is FINAL winter forecast...OK? AS Many of you know I am moving to far N VA after the long holiday weekend... to Ashburn VA.

Not only I have sign up with several new energy clients but the last 3 or 4 weekend have been spent looking for a new house which would of been the time I get a chance to work on the New winter forecast... and of course those paying my Fee get the forecast 1st... YOU guys get it second.

You dont like you can kiss my hairy ass.

edited this out ..........

The fact that I dont see this winter as being all that warm and snowless does not mean I am engaged in a nefarious plot to have it both ways. One would think it would be a big to be allowed to make that point but unfortunately the Mods at eastern think that any defense of myself is uncalled and should not be allowed. Go figure...

The purpose of this blog is to allow folks to read my stuff and not have to put up with any bullshit. You can ask anything and post anything you want to... rational dissident is allowed. You cross the line once I will kick you arse and ban you. I will tell you what I think... why I think it and make other obnoxious comments. There wont be any bullshit here.... wrisk has made a name in the energy and ag markets b/c I dont bullshit folks.

I tell them when I am right but more importantly I will tell them when I am WRONG ... (I dont do the accu wx pony and pony show here) and when I dont know.

Will this blog amount to anything ? Beats me.... but dont underestimate DT. Here I am 8 years after getting kicked out of NWS as a new force in the energy markets and nearing 80 million hits on my web site and I have never advertised a day in life. Money isnt everything folks but I must be doing something right

see ya later ya sick twisted freaks

increassing signs of major Pattern shift end of the month

2006-11-19T16:00:00.000-05:00

If you recall the euro from just a few days there was talk about the Upper that is going to form off the SE coast Tuesday.... retrograding back into FL then into the gulf of Mexico and perhaps developing some tropical characteristics... HPC even tlaked about that back on the 8th or 9th
well over the weekend the euro as well as all the MR models have been showing this coastal Low riding North bringing either heavy rains to some portions of the East coast OR Just offshore. Either way with the HIGH to the North the presure graident will increase and having a N wind at 20-30 MPH from SC to Cape cod is NOT going to allow the warmth over the Plains and Midwest to push past the Appalachains until Much later

Sorry heat mongers you ARE going to lose this one. Oh sure the Low will eventually move the off the Northeast cast-- the 12z Sunday Euro has it over SE New England. The other Key point about this that this Low is the 5th or 6th major to develop or affect the East coast since OCT1.

what does that mean? beats me -- although I have some ideas... but if you think this is NOT going to be a busy winter for the East coast your are either drunk or on crack.

I see the 1st major Low for the eastern third of the CONUS this winter season in or around DEC 1 and the dramatic change in the Ecmwf over this weekend is leading me to believe the day 11-15 GFS ensmebles from last friday and yesterday might be correct

The 1st image is the 0z day 10 euro which BTW does have strong ens support from the Ecmwf ens runs... Note the Massive greenland Block .... and the breakdown of the northeast Pacfic Vortex! One can clearly see the Ridge developing in the eastern Pacific as the long wave trough forms over in the central Pacific

and the 12z euro which show major amplification underway over the eastern Pacific / west coast ... but it also has has less of Massive Greenland block . Still the 500 MB heights are over Greenland are clearly rising ....

here is the 00z GFS ensembles at 276 valid DEC 1 and as you can Many of the member have some sort of moderate to strong s/w movng though the eastern third of the US
http://www.meteo.psu.edu/~gadomski/ENSHGT_00z/f276.gif

The 12z is even more pronounced at 264 hrs-- 11/20/2006
http://www.meteo.psu.edu/~gadomski/ENSHGT_12z/f276.gif

Member P02 P03 p09 and P010 are all flat but the others members ARE impressive to say the least Now all this being said Please dont ask me if this is snow or rain.... for your area. First of all I dont give a shit about YOUR area more than any one else in case you have figure that out yet and second its way too early.

I am going to shift all my focus to the vastly improve snowstorm checklist to have to ready by the end of the month. It will stun you by its comprehsniveness and as a forecastng tool.