stadiumwave

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:

Another look. I'm sharing because this is so cool looking! Watch it eat!

Rock & roll! Happy new year!

Good old "MJO confusion" model run to run variability I think.

But at that point it's already weak & decoupled from the troposphere and it really doesn't matter. Opens the door for increase HL blocking. Also that is classic precursor to a full-blown SSW which is defined by a reversing of the winds. Smart money is it's going to occur.

GEFS 10mb Anomaly GEFS control 10mb anomaly

Organic methods still looking good for cold that 2nd week.

With a month long +PNA. So, who cares

CFS continues to show NAO & AO drop around & after Christmas.

East Asia has a lot of troughiness being modeled Dec 16-29. Per East Asia Rule, correlates to east U.S. 6-10 days later. Somewhere around Christmas through 1st week of new year. The 0z GFS & GEFS changed drastically for Christmas Eve. Trend This does not appear to be a cold outbreak but some seasonal & perhaps tad below normal when systems swing through. Would support some possible snow potential somewhere during that period . EDIT: I could've swore I saw DEC 24 on the analog map, ha. My point was irrelevant except for the Christmas period.

JMA updated...great JAN & FEB JAN FEB