SnowGoose69

The 18Z GEFS for the first time from like 360-384 shows signs of a +PNA trying to develop but I'd bet its close to the 12th-15th before any chance of it

I have not followed it beyond 48-60 with storms so far. I do know its had a bias of being too warm aloft, so basically the reverse of what the HRRR bias is

I’d give them a decent shot now but we got a ways to go. This system will probably have two maxes. The area that gets hit from the initial warm advection and clipper and then from the developing surface low offshore. Someone in between will get the shaft. Right now the prime shaft zones may be places like central MA down through CT and central to eastern LI. It’s a case where Morristown could see more snow than New Haven

I've not seen us get snow this far south with a clipper that far north that I remember. But its sort of a case of perfect timing here where it comes in after a fairly cold airmass is on its way out so you get overrunning snows. Its somewhat similar to 12/27/84 though that was more just a mid or upper level wave inducing overrunning snows than it was a clipper/warm front feature. It shows you how snow is often more luck than anything else and how in -PNA patterns it is easier for us to get lucky than +PNA ones where its more often boom or bust nowadays.

RRFS congrats NYC lol. Would not trust it at this range though

RRFS is ridiculously south. Probably can toss that. I have not looked at it much past 48 but it seems less wacky and ugly overall than the NAM does beyond that period most of the time so I guess good news there as far as improvement with the new model

The NAM appears to have NAM'd. ICON/RGEM are about what I'd expect. I think the Euro is a tad too far south with this right now.

The only thing great at the moment is the WPO maybe heading back into king territory again where it can overwhelm everything else. Otherwise the other indices do not look particularly great. That said, I do not see any shutout pattern developing either, it would still be one with chances for snow.

Yeah would not worry about that with how consistent most other models were at 00 and 06z. Looks like it just organizes everything late.

It should be cold enough easily, just need a decent shift south still to keep it all snow otherwise its quick inch to dry slot or light rain

The airmass believe it or not is better than it was with the last event. At least to start. Its 32/13 on the NAM at 12Z. The bigger risk with this is it just is largely too far north in the end.

Europe has not been cold in seemingly forever in winter. Thats the pattern that really gets them cold, though they did well in 09-10 and 10-11 (early) with a W based -NAO, overall the e based one is better though.

Yeah this just is not a cold pattern for the west at all really. The Bering Sea ridge and subsequent trof are too far west. Its a fine line for them, a 700 mile shift east would produce December 1990 results for them but as of now too much Pac air is getting into that trof so they're just not cold and won't be any time soon

00 and 97 I think also went pretty strong +PNA I think but can’t recall if they were negative in December or not. I want to say they were not

It’s going to be a battle in January I think of which one gives in first. If it’s the NAO winter is probably done for if we assume we get the February most expect we do based on the IOD/ENSO. If it’s the PNA maybe we can get a crazy 2-3 weeks. I’d still lean towards February probably being bad but in La Niña to El Niño transition years we’ve seen March sometimes be good

Thats like a -7 NAO on the GFS at 300. I'm sure the GEFS will look different.

Chances are those will be wrong. The evolution looks more like an El Nino than anything else as late January looks like the transition you'd often see begin to happen in that type of winter. I highly doubt we have a cold +PNA February

They seem to think we're in an El Nino

As long as Canada stays cold this flips quickly if the PNA goes positive if the other indices largely remain where they are. If somehow though we get a week or 2 of a GOA vortex we're probably done til 1/20 at least. No signs of that though

It shows you how a 500 mile difference in feature placement changes everything. The first 2 weeks of December 2010 you can take all those features and shift them 500 miles west and that was basically the pattern. We did not get any big or notable snows though but we were very cold.

We probably need some heavy changes if we're gonna get that 12th straight La Nina +PNA Jan after a -PNA Dec. I don't see a -2.5 on 12/31 flipping to positive before 1/10 or 1/15. Does not mean we won't see cold and snow though if the AO/NAO are negative

That looks like a lock. Unfortunately if the PNA is still -2 to -3 that won't work, even getting it to 0 is ideal

Well hopefully the GEFS idea of the SER linking with the NAO block does not happen because by the end of the run we have a decent -NAO

They got 2.8 last year and it did not turn out well

JFK broke the record from 12/14/2003 by 0.1