Momentum building for possible storm on JAN 16th?

If you have been following along in the long range thread, you would have read some of us - mostly myself and Ray - downplaying a possible coastal storm for Sunday into Monday next week. Because of an ocean storm over the Atlantic and the timing of other upper pieces of energy, we felt the Sunday-Monday storm will stay to our south and impact mostly the Mid-Atlantic.

However, over the last 24 hours I have outlined reasons how this storm can still hit us, and hit us hard. It has to do with seeing favorable trends aloft that have to do with wave spacing and stronger Atlantic blocking (-NAO). Now, we are seeing models coming around to the idea of a storm that does not stay to our south, but in fact track north and potentially drop Godzilla-type snowfall amounts over our area. The trends over the last 48 hours have dramatically seen east coast heights rise exponentially Saturday into Sunday as evidenced below.



The red shade over the Northeast is indicative of heights trending positive while heights in the SE are trending negative, which is the storm system of interest. Let's look at the same map but for all of North America.



If we focus our eyes much further north, you will see trends over the last 48 hours show positive heights over Greenland (-NAO) and lower heights just south of there which was the Atlantic storm (I've been calling it a Nor'easter). This Nor'easter is now positioned much further north and is acting as our 50/50 Low within the 500mb evolution for a possible storm 16th-17th.  

Check out where today's 12z GFS puts the H5 upper level low valid for Monday morning. Coming right up the coast.



This is where yesterday's 12z GFS valid for the same time frame had it. Meandering aimlessly out to sea.



So, the changes we're seeing aloft are having a big impact on what's going on at the surface. What once looked like a 'southern slider' now could be a Godzilla-like storm. We are still a long way from knowing the final outcome. Models can easily trend back to their initial idea of a southern slider. Models could also be weakening the Atlantic storm/Nor'easter TOO much, that it in fact causes blocking to our north to be too weak, so that opens a path for the storm system to track west of us which would mean heavy rain for the coast and heavy snow N&W of NYC. Or, the third possible scenario is a track just off the coast near the benchmark.

We have 3 possible scenarios. This is where I'm placing probability right now:

1) Southern Slider - 40%
2) Inland Runner - 30%
3) 40/70 Benchmark - 30%

So let's see what these trends look like over the next 3 days. Also, for those who want an educational watch I am also linking Ray's video from yesterday which explains his thoughts on this possible storm.

https://drive.google.com/file/d/1FPOUBlBym2N23_O71NDpoZ0zzf2Y_kQB/view?usp=sharing

Grazie amici

The ensembles - which had been keeping this storm well to our south and east - are now coming in with what looks like a hit for our area.

Here's a look at all of the members of the GEFS. Lots of coastal storms, but also some tracks that would cause warming at the mid/upper levels along the coast. These types of details shouldnt even be looked at anyway. Biggest thing is trends trends trends

Frank_Wx wrote:The ensembles - which had been keeping this storm well to our south and east - are now coming in with what looks like a hit for our area.

This does not tell the whole story. AT ALL. Take a look at the actual spread of low-level centers. It’s a bimodal distribution, with a HARD west lean in Op’s camp being skewed by fewer eastern outliers. Massive shift from previous runs.

Great minds think alike haha

With such dramatic changes at H5, one would think the EURO has no choice but to follow suit westward.

Major changes on GEFS!

Personally, I think is an over-correction, and that the central Mid-Atlantic is still the sweet spot, as we’ve discussed, but this remains a viable option and certainly has me concerned that I may have reversed course from my longstanding feelings on this period too soon lol

UKIE!!!!!!!

nutleyblizzard wrote:With such dramatic changes at H5, one would think the EURO has no choice but to follow suit westward.

Not necessarily. The EURO suite usually does not make such drastic changes in one run, as Scott has previously pointed out. It’ll change incrementally across several cycles, IF it does. We’ve seen many times when the GFS separates itself from the EURO and the two camps battle it out until the end. The most recent example of this being last week when the EURO suite remained offshore until the event was within about a day, then it caved to the GFS suite. This time it could go the other way, as we’ve also seen the GFS suite be too aggressive with coastal storms a few times this season.

The best way to assess which is more likely to be correct is to “simply” figure out what changes make the most sense within the context of the larger synoptic pattern. I think a northward shift from snow in the Deep South makes perfect sense, and id why I targeted the Central Mid-Atlantic as the bullseye here, but I don’t think that the end result will be further north than that (at least based on my most recent analysis). However, as we are currently seeing, a further north correction is still very much possible.

Canadian ensembles.

heehaw453 wrote:Canadian ensembles.

This is really starting to get interesting.

I think the EURO is about to join the party lol

“OHHHHHHHHH HERE SHE COMES”

May I say it?? I think I will: MADONNEEEEEEEE

977 over KACY lol

Madonne is right…EURO is a beast

Central/NEPA - Central NY special verbatim. But again, I think this is all an overcorrection. At least for now. The important part is that there is a clear trend now to at least have a highly amplified storm in the region. Details to be determined.

If it phases with that trailing shortwave will that hold the storm back and make it run up through PA?

974mb over the NY Bight lol

It made worth asking even though it was mentioned before, should we not be concerned about most of the area showing rain but rather more excited at the idea of a major system heading our way?

The million dollar question is: does this ultimately take the goldilocks benchmark track so we can all benefit

And now all the players are on board. Except we're now to far west. Who would have thought in 24 hours the changes would be that drastic on the models.

A long, long way to go with this one. Lot's of scenarios here.