THURS 1/5/23 EVENING UPDATE on JAN 13–14 **POSSIBLE** EAST COAST SNOWSTORM

DT Wxrisk
6 min readJan 6, 2023

My goal here is to use and choose my words carefully so I can convey precise meaning as well as variables and uncertainty about JAN 13- 14

So let’s begin.

It is always important when you are doing extended forecasting of major events to begin from a premise of skepticism. By that I mean you build a case where the event could happen but also look for reasons why it WILL NOT happen — — WHAT COULD GO WRONG “? — in other words, with January 13–14 what could go wrong with the big winter storm possibility that is showing up on the European and Ukmet models ?

Not only does this prospective or Method keep your enthusiasm in check but it also allows you to anticipate future model developments because you are not caught by surprise if something changes. By anticipating failure and problems with the various weather models you are never caught flat-footed or surprised.

“ITS STILL A WEEK AWAY”

Ok here is a bit of advice for you …when and IF you read, hear.. or see or hear somebody say this to you. That person is a MORON. Let me explain.

The purpose of issuing weather forecasts is NOT to make the meteorologist look good by waiting until the last second when the significant weather events is already upon you. It is to convey information to people, businesses, and organizations that need the information in a timely manner so they can alter their plans accordingly..

As you will see on the maps below IF the current data on this Thursday evening is correct then it will be snowing moderately by Friday morning 13 January 7 am across most of Virginia, western and central North Carolina, as well as eastern Tennessee and southeast portions of West Virginia. And there could be significant ice as far south as Greenville Spartanburg SC and northeast Georgia.

This means that the forecast has to go out by Wednesday afternoon or evening NOT Friday morning JAN 13 when the event is already underway!!!! Any dumb stupid ass dork can look out the damn window and tell you what’s going on Friday morning.

I am sure this is going to come up several times between now and next Wednesday. If you recall the early forecast regarding the December 22–23 Midwest blizzard — — it was initially being portrayed as an East Coast Winter storm by the GFS models. The other models such as the Ukmet , the European, the Canadian, the Icon/ German, all showed a MIDWEST winter storm of severe intensity followed by the Arctic outbreak.

With regard to January 13–14 the fact that the last 6 run of the GFS model is not showing ANY kind of winter storm January 13–14 for the East Coast. The point here is that beyond 84 hours, the GFS continues to have problems forecasting the winter storms on the East Coast with any degree of accuracy or skill when compared to the European and Ukmet models. Now some may not agree with my assertion but I have been doing this a Looooong fooking time. In other words the fact that the GFS model does not have any hint of a winter storm on January 13–14 — as of this Thursday evening or Friday morning — has no bearing on anything from MY perspective.

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Obviously, a big concern given how mild it has been has to do with temperatures both at the surface and at the mid-levels of the atmosphere and whether or not it will be cold enough to support snow on January 13–14 in the Middle Atlantic. the eastern portions of the Tennessee Valley. and into Southern New England. Based upon the data — which is all I can look at right now — the answer is clearly yes. This image shows 850 mb temperatures as of 7 am. Friday morning. The values are in Centigrade and I have drawn in a thick BLACK line to show the R/S Line. As you can see the R/S line is running very close to Hampton Roads and just to the east of Raleigh-Durham. This means that ALL the precipitation to the NW…N and NE of the BLACK is SNOW on Friday morning January 13th.

These next three Maps show how the system is likely to develop based upon that European ensemble.

The European ensemble (EPS) consist of 50 different individual runs of the European model all based upon slightly different initial conditions that are run out to 15 days. You take all the members and you come up with a mean or a most likely solution. The PURPLE line represents the rain snow line at Friday 2 pm, Saturday 1 am, and Saturday 1 pm. If you look at these maps and take them verbatim then Hampton Roads and eastern North Carolina will see a rain that will end of snow as the LOW pressure area moves away from the coast. But areas such as Richmond Lynchburg Charlottesville washington-baltimore Philadelphia New Jersey could see a lot of snow.

This next image shows the total precipitation JAN 12–15 based on the Thursday afternoon JAN 15 European ensemble.

As you can see, there is a large area of precipitation amounts ranging from 0.5 to 1.25 inches across much of the Mid-Atlantic and into southeast New England. Based upon the current data — Everything north of the BLACK line is a LOT of snow with ratios of 10 to 1 or higher.

WHAT COULD GO WRONG?

There are a lot of things that can go wrong. One of them is the La Nina event itself.

If you have been paying attention to the weather maps or news stories at all, then you know that California Oregon Washington British Columbia the Rockies have been getting battered by big storms coming in from the Pacific Ocean. In fact that is why the last 7 days have been so mild across the eastern half of the country. All the arctic air is north of the US / Canada border and we have Pacific mild air dominating the country.

In order to get this big East Coast winter storm to take place in January 13–14 there HAS to be a strong Ridge in the jet stream in the general vicinity of the Rockies extending into southwestern Canada.

Right now the European and British models are showing this — a strong Ridge in the jet stream over the Rockies.

However, one of the reasons why Big East Coast snowstorms are not common occurrences with moderate or strong La Nina during the winter season is that the Pacific jet simply will not allow the atmosphere to set up in the right parameters to produce a big East coast major snowstorm.

With this upcoming event it looks like the La Nina is weakening which means that Ridge over the Rockies might last long enough so there is a big East Coast winter storm on January 13–14. But it is also quite possible that the La Nina, which is still powerful, will keep the Pacific jet stream very strong and could blast the Ridge over the Rockies apart. If the ridge Over the Rockies in the jet stream does not develop there is no East Coast winter snowstorm on January 13th of 14.

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DT Wxrisk

Meteorologist ... Atheist.. Dyslexic ..Baseball.. Fat tail distributions ..Good Judgement Projection… Black Swans/ Taleb …Choas / non Linear Dynamics… ENTP