GIVE IT TIME FOLKS

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?

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?

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

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

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

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

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

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

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

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

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

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

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