It's coming 1/31-2/1

[Brian5671]

3 minutes ago, NJwx85 said:

Yeah but you would think there would be a more expansive precip shield on the NW side. I know its occluding but it does deepen from 982 to 966 in 12 hours while just South of the area.

Yeah agreed.   Looked like a weird double low at first too-might be some convective feedback?

[MJO812]

Congrats southern Mid Alantic and Coastal SNE on the gfs.

[RU848789]

1 hour ago, donsutherland1 said:

There remains potential for snowfall on Sunday in the New York City area with an even higher probability of snowfall across eastern Long Island. What's fairly certain is that a storm will develop somewhere along the Southeast coast and possibly become quite deep. What's uncertain and subject to synoptic details (the placement of vorticity maxima, 500 mb low, etc.) that the guidance can't reliably resolve at the current lead time is the exact location where the storm will develop and its ultimate track. By Thursday, the guidance should be moving into a more skillful lead time.

As a result, there are varying solutions. Several models now take the storm out to sea with no impact on the New York City area. Others graze the region, possibly with several inches of snow. The 18z NBM even brings close to 0.50" QPF to New York City. This large spread reflects the degree of uncertainty that still exists. 

Although it looks less likely that this will be a blockbuster storm, writing the event off completely goes beyond what can reasonably be supported by the models and their ensembles. 

Here's the latest WPC probabilistic assessment of a moderate impact:

 

Don - as you know, the NBM is time lagged and in the last 24 hours there were some bigger runs of models that show little to no snow now, like the Euro/AIFS.  I don't know how far back they go, though, but it sure looks like a blend of all the models most look at wouldn't be showing more than an inch or two for 95 vs. 6" in the NBM.  I recall last week the NBM was consistently showing 12-18" for our whole region through 48 hours before the storm (when most models were showing less and decreasing), which informed the NWS-Philly's 12-18" forecasts at that point - but then the NBM dropped a decent amount over the next few runs, such that the NWS stepped down several times from 12-18" to the 7-11" amounts they had for most right before the storm.  It's hard for me to imagine, right now what is causing the NBM to currently be so high. I'm not saying the models can't shift back in such a highly volatile setup, though, especially as we saw a shift north of about 150-200 miles from about Day 5 to Day 3 last week (and it kept going north). 

[North and West]

"I would take it - probably best 7” I ever had"

.

[NEG NAO]

7 minutes ago, NJwx85 said:

The kicker was weaker this run.

and the kicker hasn't even been properly sampled  that energy is still out in the pacific and the energy that will generate the trough in the southeast is still way up in Canada not properly sampled yet - so the storm right now is modeled to be right on our doorstep so expect changes as we get closer

[donsutherland1]

1 minute ago, RU848789 said:

Don - as you know, the NBM is time lagged and in the last 24 hours there were some bigger runs of models that show little to no snow now, like the Euro/AIFS.  I don't know how far back they go, though, but it sure looks like a blend of all the models most look at wouldn't be showing more than an inch or two for 95 vs. 6" in the NBM.  I recall last week the NBM was consistently showing 12-18" for our whole region through 48 hours before the storm (when most models were showing less and decreasing), which informed the NWS-Philly's 12-18" forecasts at that point - but then the NBM dropped a decent amount over the next few runs, such that the NWS stepped down several times from 12-18" to the 7-11" amounts they had for most right before the storm.  It's hard for me to imagine, right now what is causing the NBM to currently be so high. I'm not saying the models can't shift back in such a highly volatile setup, though, especially as we saw a shift north of about 150-200 miles from about Day 5 to Day 3 last week (and it kept going north). 

Yes, I'm aware that it's time lagged. Nevertheless, its 18z data was probably reflecting the 12z suite or perhaps slightly later. At this timeframe, the details don't matter too much. I just wanted to illustrate that there are alternatives to a clean miss. I suspect that a solution that grazes the coast might currently be the most likely scenario. That would allow for a light snowfall from Philadelphia to NYC and moderate maybe larger amounts across parts of eastern Long Island into southeastern New England. The Cape could do quite well. Having said that, it's not uncommon for model tracks to vary by 50 to sometimes 150 miles over a four-day lead time. I suspect that by late tomorrow or Thursday, we should start to be able to pin down the details with some degree of confidence. 

[NEG NAO]

4 minutes ago, donsutherland1 said:

Yes, I'm aware that it's time lagged. Nevertheless, its 18z data was probably reflecting the 12z suite or perhaps slightly later. At this timeframe, the details don't matter too much. I just wanted to illustrate that there are alternatives to a clean miss. I suspect that a solution that grazes the coast might currently be the most likely scenario. That would allow for a light snowfall from Philadelphia to NYC and moderate maybe larger amounts across parts of eastern Long Island into southeastern New England. The Cape could do quite well. Having said that, it's not uncommon for model tracks to vary by 50 to sometimes 150 miles over a four-day lead time. I suspect that by late tomorrow or Thursday, we should start to be able to pin down the details with some degree of confidence. 

BIG difference in accumulations from 50 to 150 miles if that is westward - doesn't make sense that there will be a hard right turn at Hatteras

[NJwx85]

18z ICON says congrats Bermuda.

[nycsnow]

Just now, NJwx85 said:

18z ICON says congrats Bermuda.

It’s ensemble was completely dif and significantly west 

[David-LI]

Mandatory “This is exactly where we want the models to be this far out” daily comment.

[Stormlover74]

2 minutes ago, David-LI said:

Mandatory “This is exactly where we want the models to be this far out” daily comment.

It is unusual having the gfs the furthest nw

[Brian5671]

1 minute ago, Stormlover74 said:

It is unusual having the gfs the furthest nw

Let's hope we see Euro/AI move west now

[Franklin0529]

Gefs is more nw then 12z. 

[NEG NAO]

10 minutes ago, NJwx85 said:

18z ICON says congrats Bermuda.

the ICON is a second string model at best - especially the OP version

[nycsnow]

Gefs n/w 

[NEG NAO]

1 minute ago, nycsnow said:

Gefs n/w 

surprised its only 991 was stronger earlier  ?? or was that other models ?

[Nibor]

2 minutes ago, Franklin0529 said:

Gefs is more nw then 12z. 

It’s had several runs moving further north west now. Complete opposite of the EPS. 

[TJW014]

Quote from user FXWX on the New England sub...

"Growing up during the age of Miller A's, I will say this...  Some of the biggest busts I've witnessed and studied were intense Miller A storms.  Error / bust potential is often much less when dealing with Miller B events.  Given the historic look of the absurdly digging 500 mb trough, I would be very wary of this escaping too far east?

While history making events are always possible, that 500 mb evolution is beyond extreme!  If it develops as modeled, then it's one for the record books.  I think it would be wise to assume its (500 mb) intensity is not going to be as intense as modeled. 

Lots to consider; where will the primary form, does it jump / reform well to the east, or does it get tugged westward, stall, loop, ???

Thumb through the Kocin book(s) and you will find examples of Miller A's that were expected to graze southeastern SNE, and to everyone's surprise, ended up throwing heavy snow back into eastern NY?  Not saying this one will, but the evolution of the 500 mb level tells me this is not a simple escape east situation.

I think a more western track evolves on modeling tomorrow."

[MJO812]

5 minutes ago, nycsnow said:

Gefs n/w 

Several inches for us 

[EasternLI]

Yeah, this works for now.

[Franklin0529]

 

[MJO812]

Jeez

[WestBabylonWeather]

Nice trends. But correct me if I’m wrong. In this particular range we want EPS on our side not the GEFS

[Franklin0529]

I got a feeling euro gonna show a move west. Rgem looks identical to the GFS @84

[SACRUS]

4 minutes ago, Nibor said:

It’s had several runs moving further north west now. Complete opposite of the EPS. 

 

It is odd and usually you'd argue it'll come north at some point but it being an almost complete outlier, the 12Z GFS was similar, makes you wonder.

 

[nycsnow]

GEFS is almost 1 inch QPF

[nycsnow]

3 minutes ago, WestBabylonWeather said:

Nice trends. But correct me if I’m wrong. In this particular range we want EPS on our side not the GEFS

Pretty sure Gefs sniffed the n/w trend first last week I could be wrong though 

[Tatamy]

Icon EPS mean 18z

[Brian5671]

1 minute ago, nycsnow said:

Pretty sure Gefs sniffed the n/w trend first last week I could be wrong though 

No-euro and euro AI led on that one

[Tatamy]

18z GEFS mean