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Model scoring and verification has decreased since early December. So uncertainty in this pattern is higher than normal.

Do you feel the GFS suppresses coastal low pressure incorrectly as a bias? Earlier in the month it had this storm further out in the Atlantic only to correct West. Also I read that the warm pool in the NW Atlantic may be playing a role by enticing the block to connect to this area by the way of a ridge and hence cause the coastal to be more of a inland runner or coastal hugger. This warm pool has been a persistent feature and was even focused on during the summer as part of a study on marine heat waves where certain ocean SST anomalies are significantly above normal. So we have anomalous - AO but also anomalously warm sea surface temps in the NW Atlantic. I imagine possibly competing forces for our area. Maybe this feature becomes less of a concern next month.

Couple interesting - AO records broken for the first half of December. Posted this evening from Don Sutherland: The preliminary Arctic Oscillation (AO) was -3.216 today. December 1-15 has experienced the strongest AO block on record for the first half of December. The AO averaged a preliminary -2.908 (old record: -2.138, 1985) with 8 days at or below -3.000 (old record: 6 days, 1966).

Drifting snow with arctic cold AFTER the storm would bring back memories of old time winters.

I like

Hour 189 WOW

Major cyclone going to happen this run. Really digging

EPS also likes the idea of the system on the 26 th. GFS and EPS both like that time period.

This is from a lack of phasing, imagine the possibilities if things work out timing-wise.

Another one for the low lands, or at least it appears that way currently. I recall a Nina snow event in the early 2000's and it was brutal after the snow. These twin snowstorms could cause significant disruptions in travel if they occur. Whatever falls will be around for a while, no doubt very cold with dangerous wind chills.

I remember that well. Philly with 14 inches I believe, then a sharp cut off to the West going from significant to nothing in a matter of miles. Snow basically moving due North with a super sharp West wall cut off. So depressing. Second to that was the Pamela Anderson bust, as DT called it. March 6 th I forget the year maybe 2001 ? Calls from Accu weather, Paul Kocin and others for 16 to 22 inches of snow. As we all know, a total bust with only trace amounts. Hopefully this time we score.

1 2 punch

Jeez, another @CAPE Dewey beach blizzard

Wow ! big changes for the better. Vort really digging

Amazing how quickly the + PNA forecast came about. Today it appears even more positive for next week versus yesterday. HM feels the + PNA signal is real. I believe we want a more significant+ PNA next week to drive our disturbance South. The snowier and more favorable EPS clusters have a more pronounced+ PNA.

Nice comparison. Next week we follow the same general idea. Deeply negative - AO peaks shortly, maybe -4.25, then moves slowly back towards neutral next week.

HM is onboard

Things looking good moving into Jan. PV still under pressure even though it may temporarily get a little stronger. Scandi High and good support for a + PNA. Also looks active. Exciting possibilities next week and later in the month. EPS had some really deep members at this range for the 23 rd. Could be a rather intense cyclone along with very high winds.

The outcome for the system on the 23 rd might be similiar to what is going to happen tomorrow into Friday. Dr No probably has the right idea as @CAPE reviewed the differences between GEFS and the EPS regarding the system on the 23 rd. Difficult to think we fail moving forward with a - 4.0 AO and block north of Alaska There is generally a lag from 5 to 10 days after these indices peak negative, but I am not seeing a significant snowfall mean acrosss our area at this time.

Still very much like the period from 12/20 to 1/10.

Tomer Burg feels the period near December 23 rd will have downstream cyclogensis, but feels currently the data favors inland locations. He did stress though this is based on the "current" data.

Snow should be nearby. The real window for significant snowfall in our region might be right after this time period. Of course, I gladly take a SECS prior to Christmas. To have that airmass over snow covered ground would be epic ! The depiction of snowfall from the GEFS is interesting, thought there be more of a Tenn. Valley component.

GEFS trends continue to get colder and the extreme departures are moving East.

Another reinforcing drop in the - AO towards day 7 through 9.

@bluewave since we are getting deeper into December would that association, with the - 4 AO and the block North of Alaska, work for areas near Baltimore and Wilmington, DE. regarding snowfall ? Thanks