ORH_wxman

There’s some decent energy rounding the base of the longwave trough after it moves east a bit so we get this brief window for a more coastal system. I think most subsequent threats beyond that are likely to be SWFEs. Previously for 12/2-12/3, the southern stream energy was hanging back in the southwest while northern stream moved over us…then, when the southern stream ejected a day or two later (say getting us by 12/5ish…which is why we were saying post-12/3 looked decent), it would push a SWFE up into the cold that was established ahead of it by the northern stream…but it’s not evolving like that now…instead, they are almost moving together so we get this threat to potentially materialize on 12/2…southern stream still lags a bit which is a good thing because it allows the baroclinic zone to set up offshore. But it’s still close enough that it can produce a coastal on some of these runs.

EPS looks pretty decent for a week out. I like seeing those gulf lows a bit offshore at this point. We know how those can trend.

Yeah could be old school pond skating by 12/15 if some of these runs are correct.

Worst cutter I’ve ever had. Even dendrite got wiped clean after having feet on the ground and his area is CAD-central. It was like a southerly mild gale all the up to Quebec City. My previous worst had been 1996. We had so much snow OTG (and dense) from the double barrel storms earlier that month and an epic 60F+ screamer wiped it all out. But 2020 was worse. It was more snow and the melt happened even faster.

Y’all can go to the December thread.

Likely a top 10% skiing December up north. Lots of early cold for snow making and plenty of natural snow chances. EPS coming in colder in that D10-12 timeframe. Trying to amplify that WPO ridging more. That’s a good sign if we can make that a theme going into this month.

Euro looking a bit like GFS for 12/2-3

Def a lot lore interesting on GFS for 12/2-12/3. Still selling that even for now…early if it happens.

Too much absolutism here. We don’t even know how things will look beyond about 12/14….weeklies actually load a bit of a western ridge leading into Xmas week. Don’t know if I buy it, but there’s plenty of ways to snow if we can keep frigid air in Canada close by which looks to be the case at least. Our glory days of December had cutters too in the 2000s…they are likely to happen.

Kind of wish the -NAO didn’t disappear on us. Guidance had been quite bullish on it for December but now it’s basically gone. Don’t need a Davis strait block but a bit of -NAO would help pin that cold a little further south. As long as we keep good cross polar flow though and that PV anomaly in SE Canada stays strong, we’ll have chances, but there’s def gonna be some risk we mix in a cutter.

Yeah let’s get the Mohawk back in the avatar and pretend it’s the late 2000s Decembers when SWFEs were a dime a dozen.

WPO/EPO cold press is really evident after about the 2nd of December. We’ll see if we can cash that in for some snow events but I’m fairly optimistic right now. I’m not full-on weenie mode like you’d see with a PNA ridge going up to Yukon Territory, but given the Niña background state and strong -PDO, this is a pretty good look for us in early December. Doesn’t mean a whole lot yet, but also I noticed the EPS mean is creeping up little by little for snowfall. It has about 3-6” across SNE now in that Dec 3-9 period. So it def has some members in there producing decent snow. I do like seeing the consistent low height max in Quebec/Labrador on that 5-day mean H5 anomaly between Dec 3-8. It’s a very good spot to hold in those arctic highs during a SWFE. We haven’t seen much of that since the glory days.

Wow, this is very impressive. Thanks for putting this together. I only had enough ambitions to do some seasonal maps and a few bigger storm maps. Doing most major storms for this long of a period is not only very impressive, but it excellent for preserving good records of storms. As the memory of those storms fade (and sadly the people who remember those pass on), we only have whatever was archived to look back on.

12z GFS def had several chances in the long range. That period after about 12/2 gets pretty interesting. There’s still risk that we end up on the warm side but I like seeing a lot of reinforcing PV shots into SE Canada…that’s ultimately what will give us the confluence and antecedent airmass we need. So the more reinforcing shots that we see on guidance, the better our chances.

We’re gonna end up like 2007 except shifted 80-100 miles north. We’ll be like NYC that December.

2008 also had a similar SE ridge (this is the setup for the prolific back to back snow events that month pre-Xmas)…the key to keeping it cold in New England is the big SE Canada vortex. If you don’t have that, you can’t hold that high/confluence long enough. Here’s prior to the 12/22/83 SWFE as well. Big massive cold dump into the plains and Rockies with decent SE ridge but we had some good antecedent cold held in by that confluence in SE Canada..little mini NAO on the ‘83 look but it’s the same idea/concept…anything to hold confluence over SE Canada. Here’s the back to back SFWE setup in December 2013 as well…look at that SE Canada region…huge -WPO/-EPO fighting that SE ridge

It’s def not a Kocin cookbook pattern at all. But sometimes our best stretches are when we have to play with fire. Ala those 2007 and 2008 type stretches with lots of battleground between SE ridge and confluence to the north. But if we’re gonna deal with classic La Niña deep -PDO and a -PNA pattern, this is one of the better ones to try and make it work…you have excellent cross polar flow showing up almost the entire run so at least we will have true arctic cold not far away.

Here’s the mid December 2007 stretch that was quite kind to the region. Esp N of pike but even that 12/13 event got your area good. 12/16 hammered pike northward. You can see that big vortex in SE Canada.

Not sure we’d need any NAO ridging with that look. That’s pretty cold. That SE Canada and Atlantic look is very reminiscent of early to mid December 2007…the WPO is more negative than ‘07 though…that’s pure cross polar there

Yeah def -PNA early on. There are some similarities to ‘07. Not exact match.

Yeah the euro was trying to get us too on that 12/3-4 system. We’ll see. Volatile solutions in this setup so I’d expect a lot of swings in guidance. We’re still in clown range anyway but these are the types of patterns you can oscillate between 60F cutters and cold SWFEs until you get inside 6 or 7 days. (In the old days it might do that until 4-5 days out)

We’ll have a torch spike on the cutter the first few days of December (whenever that thing actually cuts…still wiggle room on guidance)….but we may drop the hammer after that. Canada is frigid and we start getting that cold -WPO cross-polar press. It’s hard to stay warm with that look. I’d be surprised if we didn’t have multiple SWFE threats between 12/5-12/15. Might even be able to sneak something a touch sooner. Esp NNE.

It's funny how the objective D11 analogs right now all point to years with SWFEs in early December.....top analog is 11/29/91 (big SWFE on 12/3/91).....2007 shows up twice on the list....so do 1972, 1978 and 1983 (all 3 had early Dec SWFEs...'78 was more of a front ender cutter, but still)

Gonna be several shots at a SWFE i think in the first 10 days of Dec....pattern has that look.

Wonder when the GFS and foreign guidance is going to converge on Tday. GFS still like a full day slower with that trough. Foreign models all have the front offshore by Tday morning.