November 28-30, 2024 | NE / Mid-Atlantic Winter Storm

[Penn State]

According to the New York Times, the term “Black Friday” came about in Philadelphia during the 1960s. Crowds would gather on the Friday between Thanksgiving on Thursday and the Army-Navy football game on Saturday. Retailers looked to capitalize on holiday shoppers, while law enforcement and other essential workers endured a day of misery. Eventually, retailers adopted the term, symbolizing their business finances going from “red” to “black”. 

Well.. If the 12z ECMWF and GFS are accurate.. This will be no “black” Friday in the Northeast and Mid-Atlantic; for the region will be covered in a blanket of white! 

Of course, there are no guarantees. This set of solutions is in its infancy, and additional support will be needed over the coming days to gain confidence in a potential winter storm. Ensemble forecasts of both the GEFS and EPS show the potential for unsettled weather in the Eastern U.S. This is evident in both the 500 MB anomalies and in MSLP members. The members seem to indicate the potential for a Miller B set-up, with a low that surges into the Ohio Valley, then transfers to the Atlantic Coast. Time will tell! 

Teleconnections are sending some mixed signals at this range.. but weather gonna’ weather. The AO and NAO look to be neutral / negative, and then PNA looks to be neutral / positive around the end of the month.. all of which are marginally favorable. The MJO recently traversed phases 7,8, and 1, residing in phase 2.. which is at the tail end of favorability. Even the Bering Sea Rule (BSR) is in play with a storm being identified in the North Pacific on November 9th, about 20 days prior to this potential winter storm, falling within the 17-21 day window for the rule. 

There’s even a bit of historical context on the CPC’s 8-14 day analog centering on November 29th. One of the analogs was mid-December 2009, which was just prior to a major winter storm impacting the Mid-Atlantic and Northeast on the 19th and 20th. 1-2 feet of snow fell over parts of the Shenandoah Valley. Additional research can be  found at this link. 

So.. It looks like there’s quite a bit to discuss over the coming days! This timeframe looks primed to produce a significant event, with ample cold-air injection and blocking. Let’s keep our fingers crossed 🤞 for an event that satisfies the winter weather appetites of those across all regions! 

Happy Tracking 🤓

 

Model Guidance | Winter Storm Origin (Hour 216) 

12z ECMWF 

Ensemble Forecasts | 500 MB Height Anomaly (Hour 216) & MSLP Members (Hours 180-252) 

12z EPS

12z GEFS 

 

Spoiler

Operational Model Forecasts | Surface, 500 MB Vorticity, & Snowfall (Hours 180-252) 

12z ECMWF

12z GFS 

Teleconnections 

MJO Forecast

AO Forecast

NAO Forecast 

PNA Forecast 

North Pacific | Bering Sea Rule (BSR) 

Historical Context 

CPC 8-14 Day Analog 

Surface Map | December 19th, 2009 

 

 

Edited November 28 by Penn State

[RobB]

12 minutes ago, Penn State said:

Well.. I suppose this needs some discussion. 12z GFS initiated, and the 12z Euro provided support. Full write-up to come later! 

Happy Tracking 🤓

Good luck.  I started similar thread for the MW/OV region.

[Poco]

bringing this over from the general Nov disco 

east Asia has very strong Mongolian ridge a steep energized mid continental trough and more energy off the coast along with a surface lp.  Very good organic ingredients for some type of coastal in the recurring rossby wave train. 
 

from a zoomed out look on the 12z euro 

I see a blocked and buckled downstream flow with a positively oriented mid continental ridge extending up all the way into Baffin Bay which results in a negatively oriented closing trough over the east coast.  
 

being that it’s an operational model under d10 with  an Organic forecasting signal with it, it appears to be a pretty large potential.  After the 12z operational runs today I expect WPC to be mentioning this on their next LRD

seeing a clearer signal on probalistic modeling (ensembles) would be the next big step towards solidifying this potential.  Look for ensemble support over the next couple days 

Edited November 20 by Poco

[Poco]

just for fun 12z euro reflectivity, certainly has the “look” to it 

[clm]

Its going to take a strong push from the north to get the temps down over Long Island to give us snow.  Been way too warm here this fall

 

 

[Undertakerson2.0]

Pac Traff-Jam - ULL has first word

Uncle Grabby or Open Wave

Upstream there be clues - half baked Alaska

First things first, as always

 

 

[AceGikmo]

I'm encouraged that all models seem to be pretty consistent with the injection of cold air in wake of the early week system (even CMC has the cold, just without any energy timing up to attack it). Will be interesting to monitor how rapidly that decays depending on the ULL blocking evolution.

Edited November 20 by AceGikmo

[GregRups]

Should be a fun day cutting down the Christmas Tree in snow.

[Penn State]

2 hours ago, RobB said:

Good luck.  I started similar thread for the MW/OV region.

Good luck to you guys too! If this happens.. maybe it can make both regions happy. It feels like this one escalated quickly.. it’s been there, but not as well defined as the 12z showed. Hopefully the models have struck on something that will stick. 

[Penn State]

2 hours ago, AceGikmo said:

I'm encouraged that all models seem to be pretty consistent with the injection of cold air in wake of the early week system (even CMC has the cold, just without any energy timing up to attack it). Will be interesting to monitor how rapidly that decays depending on the ULL blocking evolution.

Me too. It seems like forever and a day since there’s been strong high pressures modeled to the North.. After last winter’s frustration, this is a welcome change! 

[RobB]

2 minutes ago, Penn State said:

Good luck to you guys too! If this happens.. maybe it can make both regions happy. It feels like this one escalated quickly.. it’s been there, but not as well defined as the 12z showed. Hopefully the models have struck on something that will stick. 

Hope so!

[Squepp]

4 minutes ago, Penn State said:

Good luck to you guys too! If this happens.. maybe it can make both regions happy. It feels like this one escalated quickly.. it’s been there, but not as well defined as the 12z showed. Hopefully the models have struck on something that will stick. 

Thank you for opening. I saw this earlier too. Glad to see it doubled down. Hope we all get an early win here! Good luck to all!!!!

[Penn State]

Just now, Squepp said:

Thank you for opening. I saw this earlier too. Glad to see it doubled down. Hope we all get an early win here! Good luck to all!!!!

No problem! Honestly.. I saw @RobB open one for the MW/OV.. and I was like.. well, we need one too I suppose lol 😂 It’s great to see so much conversation so early! 

[RobB]

5 minutes ago, Penn State said:

No problem! Honestly.. I saw @RobB open one for the MW/OV.. and I was like.. well, we need one too I suppose lol 😂 It’s great to see so much conversation so early! 

Let-s hope later runs don't decide to pull the ole rug..LOL

[Penn State]

[Penn State]

Need you to come back south a bit.. but that’s nice. 

[MaineJay]

I woulda hated it as a kid, but as an adult with kids, I'd take the Friday after Turkey Day snow all day long.  

School is already cancelled.

[Poco]

12z eps 

 

[MaineJay]

GFS and ECMWF hot the west cost with their energy 5-6 days from now.  ECMWF has a bowling ball look, GFS with more of an open wave, but similar path.  GFS appears to entertain the idea of some Hudson Bay energy dancing with the wave. 

  Canadian is pretty different, and kinda drops energy down from central Canada.  

  

[Penn State]

Just now, MaineJay said:

GFS and ECMWF hot the west cost with their energy 5-6 days from now.  ECMWF has a bowling ball look, GFS with more of an open wave, but similar path.  GFS appears to entertain the idea of some Hudson Bay energy dancing with the wave. 

  Canadian is pretty different, and kinda drops energy down from central Canada.  

  

I was a little worried since the Canadian 🇨🇦 didn’t show anything.. but like the general consistency of the GFS thus far. 

[Rickrd]

And its not even winter yet. …. I’ll take it. 
Let the good times roll. https://open.spotify.com/track/7hVhRCDV100Jq26NGR7adw?si=YgxXOzXrR-2ytZQkD5h2EQ

Edited November 21 by Rickrd

[Penn State]

18z GEFS looking improved.. or at least with additional clarity.. over 12z

[Poco]

26 minutes ago, Penn State said:

18z GEFS looking improved.. or at least with additional clarity.. over 12z

yea 18z 48hr z500 delta 

the height delta focused right on the coast, so gefs is moving in the right direction for a clearer signal 

[Poco]

0z gfs passes a small wave then blows up something on Dec 1-2.  All bomb like in New England.  

Edited November 21 by Poco

[Undertakerson2.0]

9 hours ago, Rickrd said:

And its not even winter yet. …. I’ll take it. 
Let the good times roll. https://open.spotify.com/track/7hVhRCDV100Jq26NGR7adw?si=YgxXOzXrR-2ytZQkD5h2EQ

I finally beat my 91 year old buddy on the golf course the other day. Bested him by 2 strokes. (he's the model of the short but straight game - makes many putts in 1). He was not on his game and I was pulling shots out my arse.  

So it can snow now and I can rest on my laurels until Spring