psuhoffman

I see nothing on any guidance that troubles me much. In about a week we will start to get an idea if this pattern rolls into December. If so I will get more optimistic. So far so good.

Never had mine.

The gefs has actually been doing better lately. But that wasn’t really my point. I’m more excited by the repetitive trends in the pacific in the short term and the signs the PV is being best around in general then I am the fluxuations in the long range NAO.

You only look at the EPS?

RR would have too much fun with that.

Woah slow down. I’m still trying to figure out how to tie my shoes and chew solid foods!

Yea it does. I keep thinking how a lot of the primary and secondary analog years I found features early season snowfall. So given that and what we are seeing it wouldn’t shock me to see an actual threat pop up faster then some might think.

Thanks for posting this! 69/70 was one of my top analogs too. Pretty much agree with your expectations. Your presentation is excellent. It should be required reading as a crash course in pattern recognition and drivers for anyone that wants to get into this! Don’t be a stranger this winter. Love your input here.

Try the long range thread

@Bob Chill BTW...2002-3 shared a lot in common with those years after the blocking in December faded. From Jan on the NAO was positive with a weakly - AO and yet the pacific bullied the pattern very similar to those other years. I bring that up because 2002-3 is a great match wrt north pac SST, IOD sst, QBO, and Atlantic SST profile. The only flaw is enso. And some of those other years share some commonality to the pattern now also.

1960-61 Raging positive NAO. 40” at DCA. And the rare trifecta of above avg snow all 3 winter months. 8.7”, 13.6”, 18”. 1961, 1994, 2014 all had the commonality of extreme ridging in either the epo or pna domain that bullied the pattern downstream. They also all shared that the AO was neutral or slightly negative because the ridging in the pacific domain was so extreme it encroached into the AO domain. 1994 didn’t end as well wrt snow but it was only a slight adjustment on a few storms from being an epic snow year in DC. 1994 though featured the furthest west of the ridge axis on the pac side of all 3 years and so more SE ridging. 2014-15 was perhaps the true oddball. Yea 3 instances in 50 years is rare but 2014-15 is the only example of a raging positive NAO and AO all 3 months and still above average snowfall. We got super lucky with a consistent pna ridge and a PV often parked over Quebec for much of Feb and March. That extreme and rare combo overcame the most hostile high latitudes possible. There are no good comps to that in the last 50 years and we will probably not see it again.

The thing is usually storms run the temperature boundary. So it’s hard to get a ton of precip and be under a monster ridge all winter. It’s also hard to be near the boundary all winter and never end up on the right side for any of the storms. We only need a few to hit Climo. Rare years like 1998 can happen where the whole continent is void of cold so storms ride the boundary between sun tropical and cool but not cold enough air but that’s rare On the flip side it’s also hard at our latitude to be consistently so far north of the boundary all winter that we are just cold/dry for a very long stretch. Yea 1977 can happen but that’s equally rare. What’s more common in a bad pattern is that we get transient cold where we never make it that far into the cold airmass and there is no mechanism (blocking/displaced PV/ 50/50) to resist the push of warmth that will naturally come with the next “wave” in the atmosphere. Without any resistance once the flow backs ahead of the next wave the boundary races to our north and the storm cuts as it rides that boundary. Hence warm wet cold dry. But other than having fun with the running joke that’s not really a problem of “dry during the cold”. It’s a problem of the longwave pattern not being right to offer enough resistance to the WAA that’s comes with 99% of any precip event (other than that rare late bombing perfect coastal we get once every blue moon while a white elk runs by and a leprechaun does a jig on the roof). Usually we can see hints of that problem in the pattern. Any really cold pattern is likely to be a little “dryer” since storms run the boundary and if we are that cold the boundary isn’t likely close. But sooner or later a wave will come and of there is enough resistance in the flow then...boom. Give me the right longwave pattern from range and I’ll take my chances on the details once the short range comes.

Guidance hints at a split flow to me with energy crashing into the west that occasionally lowers heights there. That can work. Probably not in late November but give me that setup between about Dec 15 and March 5 and I’ll roll the dice.

Eps had no appreciable change from the last few runs.