snowman19

I’m starting to think around 12/20 there is a relaxation of the cold. Before I get attacked, no, I’m not saying torch. Just want to make that clear because as soon as you say “relaxation” of cold, some people automatically think torch, I’m definitely not saying that but I do think there is going to be a relaxation. I also think the pattern over the next 14 days, at the very least and real likely longer than that, is going to be extremely hostile to I-95 corridor snowstorms. Clippers? Sure. Overrunning? Sure. But classic east coast snowstorms/nor’easters? Color me very skeptical

The new HRRR and RAP on Pivotal are showing 0.1 and 0.2 of snow respectively and no freezing rain in the metro overnight. HRDPS isn’t showing anything and neither is the RRFS

The EURO AI flip flops like a fish out of water. It went from showing a non stop arctic tundra this month to showing this by 12/19:

That big SOI drop/strong -SOI correlation to strengthening the STJ only works during El Niños, not La Nina’s. Unfortunately many years ago, JB spread the completely false narrative that big SOI drops, no matter what the ENSO state, result in an energized southern stream (STJ) and east coast storms and it got taken for fact and people ran with it…

Several years ago HM did a write up on this. There is a SOI correlation, but it’s during El Niños only. As I’m sure you already know, the STJ is driven by thunderstorms in the tropics and the polar jet is driven by temperature contrasts. Strong -SOI enhances Nino related thunderstorm activity in the tropics and subsequently strengthens the STJ, which is already beefed up by the standing wave El Niño convection on the equator. When there is a big drop in the SOI, the southern stream gets enhanced and the chances for east coast storm activity goes way up afterwards. This does not apply during La Nina’s. Many years ago, JB decided to incorrectly apply and hype big SOI drops to corresponding to STJ/southern stream enhancement, east coast storms and arctic outbreaks during La Nina’s and it was taken to be fact by the weenies and I guess even by some mets… @donsutherland1 Any stats on this?

Yes, that SOI correlation only works during El Niños, not during La Niña’s. Unfortunately JB spread false info about it years ago and many people (apparently even some mets) believed him

Mike is completely wrong about big SOI drops in winter corresponding to strengthening/energizing the STJ and causing big east coast snow storms and arctic outbreaks. That correlation only works during El Niños, not during La Niñas. So Mike is spreading false info just like JB does for likes, follows, attention, retweets and subscribers. He may want to actually research the SOI correlation before he goes posting nonsense about it on twitter And furthermore, he’s dead wrong about another thing, we have not been seeing classic split-flow. That is an El Niño feature where the jet splits into 2 branches off the west coast with a dominant southern stream (STJ) and a very weak polar jet. We have a very dominant northern branch and a very muted southern branch, typical of a Niña. That tweet was full of fake news and reads like a New York Post article

Maybe we should use El Niño analogs! I’m thinking 57-58, 65-66, 76-77, 77-78, 02-03, 09-10, 14-15

At this point I don’t think the question is “will December be cold?”. Very likely to average cold. I think the bigger, million dollar question will be snow. As of right now, the pattern does not look conducive at all for east coast, I-95 corridor snowstorms. I agree with your take in the post you made earlier in that regard. If December ends up colder than normal with below average snow, I think most on here would consider that a loss

If that’s correct, a cold look for sure. A coastal storm pattern, not so much (++NAO/flat PNA). Maybe fast moving, progressive clippers? EDIT: @EastonSN+ Snowfall in -WPO patterns vs -EPO patterns is a good question. @donsutherland1 is the man to ask about that

So far since November, we’ve seen -WPO (Aleutian ridge regime) driven cold. This is in contrast to the -EPO (Alaskan ridge regime) driven cold we saw last winter….. @SnowGoose69 @donsutherland1 @bluewave

That’s exactly what the GEFS is showing; an Aleutian ridge regime (-WPO) as opposed to an Alaskan ridge regime (-EPO)…..

Verbatim, it’s showing an Aleutian ridge regime (-WPO), if it goes poleward, as is being shown, it would tap cross-polar flow/arctic air into western Canada

Zip zero