stadiumwave

I'd also like to say those who championed the -PDO (I call a hybrid -PDO) thinking it would lead to deep, constant -PNA. Well, the observations pooey that. It's been anything but the case. We've spent very little time in -PNA territory since early SEPT. With the SST's the way they are it's muting the effect of what is a strong -PDO on the index. Just keep that in mind. I think the PDO index is faulty here. The weak orientation of a further west mean trough coming up is going to be due mainly to MJO, Phase 3....not -PDO. BTW, I think it's weak PHASE 3 & organic methods show the trough swinging back & forth & certainly not constant ridging in the east. The greatest threat of stubborn ridging will be in NE from -NAO, which sometimes still works out well (2010 +anomalies in NE heights but still had some big snows).

#1 GEPS still spilts for a bit #2 EPS still splits at 50mb, 100mb, & 150mb #3 EURO at 10mb looks like it's on its way to splitting but also it's warming orientation is different than other models pushing than main lobe to North America #4 GEFS & GEPS have additional warming event after the first event starting over Asia around JAN 14, also on GFS #5 With all that said, a full SSW is not needed to get to where winter lovers would like to be. We're likely headed that way either way & whether we get a full SSW the SPV looks to keep taking hits remaining weak.

GFS OP & GEFS both advertising another warming strat warming episode beginning on the heels of this & really ramping up by mid-Jan. If so then no doubt stays weak a long while. 2nd warming may deliver the goods if it occurs.

0z Euro starts to split SPV at 10mb & 50mb on day 10 (end of run).

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