E PA/NJ/DE Winter 2025-26 Obs/Discussion

[MickeyTim6533]

38 minutes ago, PhilsFanDrew said:

No we aren't.  The piece of energy that is responsible for this storm signal hasn't even made landfall in the US so models are basically guessing at this point until it can sample it.  

ocmd buried

[MickeyTim6533]

just not enough negative tilt yet

[Duca892]

So this run it just gets up to a certain spot and then just heads on out 

[Newman]

Verbatim, the storm occludes too far SE for the majority of SE PA. Again, if we get similar evolution but the shortwave doesn't dig as far south, this occludes right at our latitude and we get those massive totals that are currently depicted over Richmond. Need to see the Euro at least trend towards this,

[ChescoWx]

[mattinpa]

Just now, Duca892 said:

So this run it just gets up to a certain spot and then just heads on out 

At least it is definitely in the right direction. Today is a big day for seeing any trends. 

[ChescoWx]

2 feet up to AC on that run....several inches of snow back as far as Chesco

[Duca892]

It just looks weird I was getting HYPED seeing it. The Low literally just stalls. Heads due East, then South East, and then North East lmfao. 

[zenmsav6810]

 @Ralph Wiggum and the models have had this signal sniffed out for weeks. Someplace is getting a storm even if it is OTS. 

[JTA66]

A long way to go. Maybe it ends up being a whiff. But this is where I want the GFS at this stage.

[MickeyTim6533]

positive tilt on CMC, no go 

[The Iceman]

Man, there is nothing more that I want to do than watch models roll in all day, unfortunately it's my busiest week of the year with W-2's due out, and we're a day behind due to the snow. From the brief look at the ICON, GFS, and CMC, positive trend at 12z. Glancing blows but we are a longggggggggg way away from anything set in stone. 

[Mikeymac5306]

Baby steps.  

[coastal front]

CMC stills get close to a foot on the coast. We don’t want this to wrap up and occlude to far south so staying positive tilt a little longer could help those farther north.


.

[Chadzachadam]

13/30 GFS ensemble members were a big hit for SEPA. think this is kind of an all or nothing deal with the complex dynamics, although it is possible we could pick up a couple fluffy inches in some of the OTS scenarios. 

random question but any chance we get dry enough for some of the existing snowpack to sublimate this week? 

[MickeyTim6533]

EURO just said no go

[MickeyTim6533]

12 minutes ago, mahantango#1 said:

JB said this morning he's not giving up yet on the storm.

 

[Birds~69]

Patch knows I'm a weenie. Sends me stuff all the time like a little kid and candy.

NWS realizing there's some potential...  

[Lucy Pull]

1 hour ago, The Iceman said:

Man, there is nothing more that I want to do than watch models roll in all day, unfortunately it's my busiest week of the year with W-2's due out, and we're a day behind due to the snow. From the brief look at the ICON, GFS, and CMC, positive trend at 12z. Glancing blows but we are a longggggggggg way away from anything set in stone. 

Agree, delicate setup.

Would like to see the ULL not dig as far south and trend negative a bit sooner. 
 

Climatologically speaking a storm of that magnitude as portrayed by the GFS in the South is extremely unlikely. Although anomalous setups can produce anomalous results.

 

[Newman]

Top 3 CIPS analogs this afternoon based on the 12z GFS:

1. Jan 2016

2. BDB 2010

3. Jan 1996

There's my weenie contribution for the day, because yes we have time to draw this back NW but the Euro remaining put doesn't inspire confidence.

[Duca892]

Are there any other time periods that are of interest coming up? 

[The Iceman]

Just now, Newman said:

Top 3 CIPS analogs this afternoon based on the 12z GFS:

1. Jan 2016

2. BDB 2010

3. Jan 1996

There's my weenie contribution for the day, because yes we have time to draw this back NW but the Euro remaining put doesn't inspire confidence.

FYI that was a positive bun  what are the key differences between the GFS and EURO, because it doesn't look far off at all at 500 MB. 

[Newman]

4 minutes ago, The Iceman said:

FYI that was a positive bun  what are the key differences between the GFS and EURO, because it doesn't look far off at all at 500 MB. 

Ridge out west is a bit more amplified on the GFS, better wave separation between our 50/50 and NS shortwave cutting off, and the decaying NAO block is a bit more stout on the GFS forcing the wave more meridional -> pinches off sooner. You're right though, things don't look too dissimilar broadly but it's such a nuanced setup.

Looking ahead, you want to see the GFS continue these trends and/or hold them. And need the Euro to adopt greater wave separation with our stretched out TPV. We want subtle ridging to build into New England where the Euro right now has the vorticity ribbon draped and keeping heights too low.

[Birds~69]

1 hour ago, Birds~69 said:

Patch knows I'm a weenie. Sends me stuff all the time like a little kid and candy.

NWS realizing there's some potential...  

Now Accu Weather's quick long range take.

Means nothing but I just like looking at it. That would be two Sundays in a row with some substantial cold sandwiched in-between...

20F

[Albedoman]

38 minutes ago, Newman said:

Top 3 CIPS analogs this afternoon based on the 12z GFS:

1. Jan 2016

2. BDB 2010

3. Jan 1996

There's my weenie contribution for the day, because yes we have time to draw this back NW but the Euro remaining put doesn't inspire confidence.

Jan 2016  is the best comparison   96 was a differnent animal as it dug in more with the trough and sucked up the GOA moisture too

[JTA66]

Getting some stray flurries, 20F.

[Duca892]

Jan 2016 I can't remember if anything was showing a hit prior like it is not right now. All I remember is the NAM locked in on our area getting destroyed and slowly but surely everything else trended towards it. 

[The Iceman]

New WPC discussion is a fantastic read

Quote

...Confidence In Impactful Snowfall Increasing For the Southern Appalachians and Southern Mid-Atlantic... To say there remains a large amount of model spread in the potential winter storm beyond Day 3 would be an understatement. In the past 24 hours, ensemble guidance have flipped camps to where the GEFS are the snowier members, CMCE are more in the middle, and the EC-EPS are trending less snowy. It is worth noting that AI ensemble membership are not as snowy as the GEFS, but show a little more snow than the EC-EPS, making this an interesting test in how the AI ensemble membership performs. Regarding the setup-- WPC Cluster Analysis shows this potential winter storm comes down to several factors: 1) strength of the emerging Great Lakes shortwave trough. 2) speed of the shortwave trough. 3) tilt/amplitude of the shortwave trough as it tracks east. 4) Confluence strength near Nova Scotia. They all work together in an intricate dance that makes for difficulties in modeling. A stronger/slower shortwave can buy time for confluence over New England and Nova Scotia to weaken, giving the shortwave more time to amplify, and allow for closer storm tracks to the coast that bring heavy snow as far west as the I-95 corridor (some GEFS members and some CMCE members). Where the shortwave is stronger but progressive, heavier snowfall occurs but largely closer to the coast and as far west as the NC Piedmont (CMCE members, UK ensembles, split EC/GEFS members). If the shortwave trough is more progressive and cannot separate itself from the larger TPV to the east there is less amplification, it results in a flatter and more positively/tilted shortwave trough, and thus the storm remains largely out at sea (EPS, EC-AIFS ensembles, some GEFS/CMCE members). It is worth noting that, while the EC-AIFS has largely performed well inside of 5 days much of the winter season, the EC-AIFS and ECMWF did suppress the track of the most recent winter storm too much ~4-5 days out before correcting northward inside of 72 hours out. This setup is highly timing dependent; from the primary shortwave trough currently east of Hudson Bay, to the interaction/spacing of the 500mb cyclonic gyres in southeast Canada and south of Iceland that promote the confluence ahead of the potential storm, to the incoming Pacific shortwaves that track into western Canada and adjust the strength/position of the western North America ridge. There remain a host of embedded shortwaves that will work together to create a complex storm evolution off the East Coast. Whatever the current model solutions show beyond 72 hours out is unlikely to be the final product. Expect additional model changes in the coming days. If there is one thing that has increased in confidence in the past 24 hours, it is the opportunity for coastal flooding and beach erosion along the Mid-Atlantic coast. Please refer to our "What We know, What We Don't Know" social media post for additional information. The one thing they do agree on is this upper trough tracks through the OH Valley Friday afternoon with sufficient PVA and 850-500mb mean layer moisture to support snow from central KY to the southern Appalachians through Friday evening. WPC probabilities do show increasing chances for at least minor accumulations >2" over KY and northeast TN, while there are low-chances (10-30%) for snowfall totals >4" through early Saturday morning in the TN/NC Smokeys and Blue Ridge of NC. Residents and those traveling to the Carolinas on north up the East Coast will want to continue following the forecasts from WPC and your local NWS WFO for the latest regarding this potential winter storm. The probability for significant icing is less than 10 percent.

 

[Lucy Pull]

4 minutes ago, Duca892 said:

Jan 2016 I can't remember if anything was showing a hit prior like it is not right now. All I remember is the NAM locked in on our area getting destroyed and slowly but surely everything else trended towards it. 

Funnily enough based off some old screenshots it looks like the euro was showing a substantial hit around 168 hours. Same with GFS around 120 hours out.

i remember them trending south and then NAM at 84hrs was the first to show a major hit north of the Mason Dixon again. 

Some screenshots leading up to event -

 

 

 

[Birds~69]

19 minutes ago, JTA66 said:

Getting some stray flurries, 20F.

Same...