COLD then NOT cold... COLD then NOT cold

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.

1. 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.
2. 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