stadiumwave

0z GFS, end of month PAC to Atlantic HLT blocking

Also, I would add Weeklies is based on 0z data. There were noticeable 12z changes on EPS, GEFS, GEPS. Ridge not ridge gone on GEPS & less prevalent on EPS & GEFS than it was on 0z for the 11-15 day. It will be interesting to see the early period on tomorrow's Weeklies update.

DEC 23-28 https://www.wxsphere.com/topic/729-winter-2025-2026/page/16/#findComment-129642

12z GEPS

I follow Max with severe weather but what's his track record with winter?

My 4 weeks post was simply looking at the previous years with early warming events, looking at the following weeks & in those few years this has occurred, it appeared to be around 4 weeks the troposphere was clearly being affected by the event, which I found interesting. Great post Don & much needed...as usual!

There can be immediate affects on the troposphere if the SPV & troposphere are strongly coupled which does not appear to be the case at the moment. If it gets immediately cold in early DEC it is not from the affects of the SSWE. And obviously there are no guarantees of how the SSWE later shakes out in the troposphere, we can only use analogs to guess.

Looking at all those years week by week every year was about 4 weeks on average when the full effects of the SSW were felt. Its a good bet the affects of this SSW will be late DEC at the earliest & into JAN.

High skill is like the last 3 days, lol. But hey, it is not usually that bad with the end result.

CFS Weeklies just now got on board with some cold. Has been baby stepping for several runs. NOV 27-DEC 7

I'd think so but I heard that talk last Nov as well. It should, but I am kind of hesitant.

What's crazy is just like last fall, we have been mostly +PNA since mid-Oct, and really since mid-Sept mostly +PNA. If that holds most of winter it would be unusual.

Sounds good to me! Hope that wins out!

Yea, the goods last long in DEC than 1st half. I was really loose with wording. And of course, we have to break before Christmas & have temporary blowtorch to get through Christmas, ha.

It updated again though. The update briefly shifts trough west but then the -EPO comes back with a vengeance & it stays very wintry look through entire month of JAN with trough east. That is what led to whoever posted that on X. In the original X-post Roundy gives explantation of the tool: https://x.com/PaulRoundy1/status/1987512542269218907?t=NZtDEqvG5ceU83Q9TrzQ9g&s=19