JAN 25-26-27 INLAND HEAVY SNOWSTORM…
1600 EST JAN 25
click on image to see full map…. NE map out at 1pm
0845 AM EST JAN 24
Finally last night the wretchedly bad an awful weather model which is called the GFS got a clue. Where as Sunday afternoon of the model had no significant precipitation – over 0.25″ — in DCA PHL BWI NYC CT or BOS,… the 0z and 6z now does.
Whereas Sunday afternoon the 12z GFS model had the Low for Wednesday morning 100+ miles se of Cape Hatteras… the 00z GFS ( and 6z ) now have the Low further to the north by 200 miles.
Whereas yesterday the12Z and 18z GFS model showed the cold air holding and that most the precipitation in the northeast would be light it also fall as snow… the 0z and 6z now drives the the 850 low deep into coastal areas of the Middle Atlantic states and force the rain snow line well to the North and West of the big cities of I95.
This is why most of the forecasts and forecasters for Western Virginia have not had any snow in the Shenandoah Valley region for late Tuesday and Wednesday. The ass worshipping of this terrible Model has really gotta stop.
It needs to be pointed out that even though the 0z GFS and 6z GFS finally has a clue of the correct solution … the correct solution has been shown consistently every day on every run of the European British any Canadian weather models models. And yet for the most part meteorologists up and down the East coast have stayed heavily focused on the GFS and have ignored the these models showing the inland track of this coastal Low.
It is beyond absurd that a professional meteorologist could ignore all the consistent data from these global models over the last four days but then become fixated or latched onto with the latest run of the 18Z NAM AT 72 HRS hrs is showing… or the latest run of the 18z GFS.
click on images for FULL size
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2330 EST JAN 22
CLICK ON IMAGE TO SEE FULL SZIE
1830 EST JAN 21
In the previous post I stated quite strongly that ….because of the upper patterns are NOT favorable for an East coast snowstorm …even though the model data on Wednesday strongly supported the significant snow event for North Carolina and Virginia January 24 – 25… I was remaining very skeptical. Clearly the data today the supports that skepticism.
Now If you are into snowstorms in the Northeast US… from VA to Maine ….and you do not have this book then you probablye are missing out on a lot of useful information which can “feed” your snow addiction.
http://www.amazon.com/Northeast-Snowstorms-1-2-Set/dp/1878220640 Now as impressive as that 2 volume book is keep in mind that that this is third version or upgrade of the book . The original version was a detailed 2 volume monograph which came in 1987…. and I have copy as well.
What even is more impressive about this 3rd edition of the book is that there is a whole section on “near miss snowstorms” and this is important because if you don’t study them as much as I do … then you will not see or detect the subtle differences in the atmosphere large scale patterns.
Now keep in mind what we are talking about here are big East coast snowstorms. We are NOT talking about moderate events or overrunning snows. We are talking about a specific type of winter storm– the nor’easter. We are talking about the DEC 25-26 2010 FEB 5-6 2010…. FEB 8-8 2010… DEC 30 2000…. JAN 5-7 1996 JAN 25 2000 just to name a few so you get an idea of what we Are talking about.
In every instance….. Without exception… There are certain features in the upper levels of the atmosphere over North America that exist when we have had these big NE snow storms develop the way they did. Think about that for second. Do you realize how rare that it is in the weather business to say in every instance without exception?
As I stated several times both here and over the facebook page… if you have recently discovered WXRISK.COM and DT….. you may have the impression that I have this “PRO snow “ bias . You may to hold the view that I have a tendency to exaggerate or hype snowstorms in VA NC MD DE. The problem is that such an impression only comes about because you have recently discovered this website . You may not have been around earlier in the decade. Back then I consistently downplayed the potential for significant snow events several days out… and I had developed a reputation of being “ANTI SNOW”.
No seriously. The point is that I had been doing this now for 10 plus years and if you were not around before 2009 then your impression is somewhat distorted.
What I try and do is walk a fine line between being skeptical and cynical. For most of the last 10 years the snow drought over central Virginia has given many of us reason to be skeptical about forecasting any sort of major snow .
Last winter when I nailed the two big early snow storms with perfect forecast five and six days out … I can tell you for a fact that ALL the other meteorologists in central and aouthern Virginia saw the exact same data that I did. But it had been so long since we have seen in a major snow in central VA… It is only natural to become skeptical and a little cynical.
To be cynical is to deny the data even when it is staring you right in front of your face. But it also has to work both ways.
If you recognize and understand the patterns which bring about east coast snowstorms and you also recognize that if you don’t have those features and place it really does not matter what the model is showing you are not gonna get the big snowstorm.
In the 33 the snowstorm case studies in the KU book… now 36 cases and growing… 31 of the 33 all featured the cold arctic HIGH being located no further to the east than 75° W longitude in the 24 hours leading up to the beginning of the storm on the East coast.
In this upcoming event the arctic cold High pressure area is already at 75 degrees W longitude when the storm begins to develop on the East coast. Now if had some sort of large system over southeastern Canada ….that would slow the movement of the the large cold High over Maine and southern Quebec Canada… and keep the cold air in place . But that isn’t the case and as a result… this High is going to slide east and move off the coast.
But there is far more concerns to the “all snow” idea than just that problem. If you recall the Model data earlier in the week… it looked like this was going to be a January 24 25 event. Clearly that is not correct as the data this afternoon and early this morning shows this will be mostly a January 25 – 26 event. This delay it also hurts the cold air supply over the Northeast US and allows cold High to slide further to the East and in turn allows for the coastal Low to come inland.
THE 0Z EURO JAN 21ST RUN:
The model had shifted the track of the entire system inland significantly because the model shows the two pieces of energy beginning to merge or phase much sooner than what it was showing earlier in the week. For this reason the model is developing the the coastal low much further inland and significantly deeper. Recall that the the early idea of this being a significant snow and ice event was based upon the coastal low being very weak…1012 to 1016 mb. As you can see the the European model early this morning develops 1005 Mb Low Located near Charleston SC which rapidly deep and some tracks over central and eastern NC eastern VA and can be found over the lower MD eastern shore by JAN 26 .
This of course was a significant change from what the data was showing earlier. Yet all the other medium range weather models – and the Canadian and the GFS — showed a significant track shift to inland early Friday morning. So it became very important to see if the ensemble data from the various models was supporting this shift inland. As you can see the European ensemble was somewhat further inland but not dramatically so.
THE 12Z FRI JAN 21 MODELS
Here is the 12z European model. The important thing to note here is that on January 25 the Low is still down over the Delta even thought the cold air is still entrenched over the NE US. But this delay is costly because 12 hours later as the Low is rapidly intensify and moving into central NC and VA the large cold arctic High is now much further to the east… So the cold air wage over the northeast us is rapidly diminishing. But in addition with the LOW…. THIS strong…. and the HIGH moving out to sea the winds are now clearly SE over VA MD DE and southern NJ. Turn it drives the warm air over the eastern NC and se VA deep into the Middle Atlantic states …. And while we have is snow rapidly changing over to heavy rain…. for all of VA and NC except for the far western portions. The Low tracks through or over NJ which would imply a significant change or mix from snow to rain over NJ NYC Long Island.
This scenario is strongly supported by the new 12z European ensemble mean which supports the major coastal Low tracking well inland. As you can see as of January 26 the Euro ensemble has the Low over Richmond and the rain snow line is north of DC into PHL and southern NJ. Again the winds over the Northeast along the coast…. EAST or SE even into CT.
Here is the 12z the Canadian model and we can see the same sort of development with the overall pattern. At day 4 JAN 25…. there are two pieces of energy which you can see as two blue lines in the Jet stream. By day 5…JAN 26 the two pieces of energy merge into one big system that develops into a negative tilt… ( NW to SE). This is a sign that meteorologists look for which show rapid intensification of surface Low pressure areas… And in this case it mains that the low pressure area is not going to develop on the coast but over Georgia. This is in strong agreement with the European models. The 12z CMC argues that eastern and/ or coastal New England would go over to rain at some point.
THE 12Z UKMET — it is very close to the European and the Canadian solution. Again we have two pieces of energy which are beginning to merge January 24 – 25. By Jan 26 we can see both blue lines are coming together and developing that made itself or tomato alignment over the Mississippi River Valley. For East coast snowstorm lovers that is simply the developing too far to the west too quickly …. and we can see the Low developing rapidly over Southern Alabama. The low moves northward up the coast so that by January 27 it is located over New England . The 12z Ukmet argues that much of coastal New England would Mix or go over to Rain for a period.
DT …WHAT THE 18Z GFS? It is all snow – or mostly snow Man!
No it isnt. The 18z GFS has the same problen that the 12z GFS has. One the Model is a piece of crap. Two …it has a serious flaw in its solution.

CANT THE LOW’s TRACK SHIFT BACK EAST?
Yes of course the weather models can and probably will shift the track of the surface Llow to the east somewhat over the next couple of days. But that really is not the point.
If that is what you are focused on…. then you are not understanding what’s going on. Weather models reflect the atmosphere . They dont have Magical Power that cause weather systems … the Lows and Highs and ridge and troughs … to move.
There IS a reason why there seems to have been this eastward bias with several of the winter storms since early December along the East coast. It was not because of magic or because the snow weenies were praying to god every 5 or 10 minutes. It was due to intense large scale blocking in the jet stream which had developed over Greenland Eastern Canada and southeastern Canada in the period from December 1 through January 10.
That was the mechanism or reason why the storms these coastal Lows were bending to the right or somewhat to the east as they came up the coast. That is now gone and because ith as faded away from the patterns over North America and the Northern Atlantic Ocean ….that tendency to shift to the right on the models as we get closer to the storm is disappearing.
Consider the last two runs of the Canadian and the European model. Those models have shifted west…. NOT east. And more importantly the Canadian and European ensemble mean maps have also shifted WAAAAAY to the West. That may be the first time we have seen that in the model trends since December 1.
SUMMARY This appears to me to be a classic I-81 SNOWSTORM IN NC and VA. IF the snow starts early enough SOME snow could fall over central VA. I reject the coastal Low track of the GFS Model becauase the GFS this far out is a piece of crap with East coast winter storms. Given is TERRIBLE track record past the 84 hour time frame with East coast winter storms …. the odds and the PATTERN strongly support the
0z EURO ….
the 0z EURO ensemble…
the 12 z Euro
the 12z Euro ensemble
the 0z Canadian
the 12z Canadian
the 0z Ukmet
and the 12z Ukmet ….solutions over the Pitiful 18z GFS.
I see DCA and BWI changing over the Rain… for some period of time. Heavy snow may fall there before the change. Frederick and Leesburg could stay all snow. This also applies to southern NJ and Philly… NYC Long Island … MAYBE coastal CT…. and southeast Mass. Again the 18z GFS JAN 21 RUN is seriously flawed and not good enough to blow my snot on.
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Great stuff! Thanks DT.
Great job explaining things D.T!
When you say it implies to NYC do u mean it could stay all snow or the part with heavy snow before the change?
Any chance of that Greenland Block coming back??????
I read your Web site for the excellent explanations you provide for your forecasts, and I appreciate the effort you put into providing those explanations. I just wish you would do something to eliminate the enormous amount of typographical and grammatical errors you publish.