stadiumwave

80-81, 83-84, 84-85, 87-88 were big snow years in the extreme lower OV.

CFS making its final moves for JAN prediction in its monthlies: Pulled the warm anomaly bubble a little NW. Thought this was interesting:

I know there seemed to be some concern models have been a little temperate with SPV forecast yesterday & today...but 0z GFS shows an SPV in serious trouble:

It'll be interesting to see for sure.

#opportunist Same with Arctic Sea Ice.

Simon just tweeted some differences between the 51 member medium range & 101 member extended range:

Correct! Which we've been saying since early DEC. I'm anxious to see what the EPS 101 member ensemble says. It just seems bizarre that almost 80% of members would have a u-wind reversal to 13% 36 hrs later.

GEFS, GEPS seem to be backing off as well. They all have an event just not as strong as previously. Simon Lee says the SPV has been knocked around since NOV & that even if this is not a "knock out punch" it will probably still get the job done as farcas sensible weather, or at least that's how I took it. BTW, it's a good thread.

Personally, I know he's doubling down but I do believe you've got to take it all in. I have a hunch MJO forecasts are impacting stratosphere forecasts.

Simon seems unbothered by 12z

Can you post? I only have access to Mon & Thurs updates.

Can't say for sure because I don't have GEFS members, but just looking at the mean I'm guessing it had some members back off as well. Maybe you have access?

Surprised no one posted this tweet

If a split occurs, starting on JAN 7 per 12z GFS & warmong across artcitic continuing through end of run....then a great chance of a good period of winter in a lot of CONUS (esp eastern 2/3) is a good probability in the future. Can't guarantee the correct storm track for anyone, but the cold at some point would be a given. Sorry for the giant run-on sentence, lol. My wife, who is an English teacher, would scold me, ha! EDIT: Let me add that I do NOT think models have a good handle yet on whether the SSW results in split, & if so what kind of split, & how long does warming last. Models may handle that aspect poorly until 5-7 days before.

12z GFS

GEFS has a split

Several ensembles & the control have split for the last 3-4 runs. This is the first GFS operational run that I recall splitting.

0z GFS

Click & read entire thread.

Just simply means a big winter storm is likely as well in 3 weeks. Smart money on JAN 9-13 timeframe....supported by BSR as well.

Hmmm

Eric shares Roundys composite. Roundys 100 day low pass constructed analog for the same date: