Stormchaserchuck1

12z GFS brough back the -EPO for early Dec Nice High pressure location.. but this is just one run

I mean if that MJO forecast verifies, it will be a weird Pacific H5 for what the MJO is. Something to watch to see if that happens: MJO amped in 7-8 and a -PNA/+AO pattern

CFS runs 4x a day, and sometimes it will have the whole US below at 12z then the whole US above at 18z. Running more helps tracking scores to improve for more data.. but 2-4 week models haven't proven much more accurate than seasonal models to this point. I personally like the 384hr map on the ensemble means, seeing what the NAO, PNA, AO patterns look like.. that is pretty accurate. There is a pretty big model drop off after Day 15. Maybe they will continue to upgrade the Euro ensembles, but they have had some big misses since coming into inception several years ago.

Remember how bad they were in 23-24? The 2-4 week period still has lot of work to do for more predictable models. There was a time in August when the weeklies had +5 around the Great Lakes and Upper Midwest for a 2-week period, and it ended up being like -5. Also, for all talk Strong Nino's get about having warm December's, you rarely hear about La Nina's and cold December's, but they do go hand-in-hand. But like I said a few days ago, when the -EPO ridge retrogrades and models want to significantly cool Alaska and NW Canada thereafter, that is a warmer pattern coming.

CPC said last Winter was the most +PNA Winter or record for a non-El Nino. Fwiw, there was a pretty -PNA period Jan 15 - Feb 10 that they were calling +PNA, but on these correlation maps what they say the index is what's used for correlations. I found it interesting that one year after most +PNA Winter's there isn't a +PNA signal the following Winter.. actually there is +NOI (+North Pacific High - the high pressure off the west coast), and that indicates more of a La Nina pattern... it was slightly predicting a la nina this winter. 1 December after last Dec +PNA... Fwiw, Jan +1 year doesn't reverse like December usually does

Dec 2021 was one of the strongest -PNA's.. what I see on models right now is a "moderate -PNA event" in early Dec. I also don't know that it sustains beyond like a week. We'll see. If it lasts into mid-December that would be a little different from what we have seen this year (where -PNA's last 7-10 days then go away).

I'm not going to bet you money, maybe another time, but I will bump this on Dec 14. I don't think you're going to get that snow.

I see +NAO/-PNA

You don't do well in ++NAO/-PNA either We may have to wait until the 2nd half of December for snowfall.

2m temps are probably too low given the Aleutian High pressure and neutral H5 over Alaska Dec 5->

I always have hard time realizing that people are illogical. It like really evokes some nasty stuff when warm forecasts are mentioned, for what I would say is a majority.

Actually the 12z GEFS looks completely different from the 0z EPS over the N. Pacific. It actually has a trough in the gulf of alaska where the EPS has a ridge. EPS has been doing better so far, but it's an interesting split. I would guess the 2 models are handling the MJO differently?

There is a lag

Alaska is a big spot. Neutral or negative H5 is going to give you a warmer pattern pretty far north. If the ridge stays over Alaska (probably unlikely) the northern areas will be cold. I'm mostly talking about Dec 6-7->