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->

Why be negative? Things change, you have to be able to change with it. "The MJO forecast way out in time" has done so poorly as a forecasting tool over the years.

That's a +400dm mean ridge over Alaska for a 7-day period. Not really the same as the 1 panel you posted above. We are going to get a -EPO period but it's not going to be as strong or sustain like 2013.

In the bigger picture, it's not really a big deal. It happens rarely. I think the other notable one was in August when a lot of models were warm in the long range and it ended up being cool.

I'm personally not a big fan on long range MJO forecastability. I've seen a lot of times actually over the last 10 years where patterns drastically change when the MJO is projected to go into favorable phases for X.

Come on man.. there is like 1 instance of a ridge leading to a trough in the east coast over the last year, and it's already been posted like 3 times lol. The large scale features held: -epo, +pna. I don't know why it had a big ridge when the Pacific looked like that anyway, but you know long range models hit at about 0.80 correlation accuracy. Especially when 1,000 mile wide features have a strong signal. It's predictable. 2-4 week models are much less predictable, there is a pretty big fall off after 384hr in predictability.

^That's a massive +NAO, MJO. With heights over Alaska neutralizing, we are going to go really warm there. These are large scale features that have a big impact on the east coast. Look at how the ridging in Alaska is just about gone in that 360hr map. If we don't hold that, the cold pattern is going to fall.

What is with these weird hours? 354hr? 306hr? We'll probably get a below average period after Thanksgiving into the first week of Dec as the EPO will be negative.. probably unlikely we see snow though. Then the pattern retrogrades and changes pretty quickly.

You're not going to get a below average temp pattern with that upper latitude and Pacific H5. That's a +2 +nao and developing -pna.. it's going to flux the SE ridge after unless the models are wrong about those 2 patterns. CFS MJO? I'd look more at the plots bluewave posted above.

That's at odds with the end of the EPS. You're posting a 1.5 day old model.

That's a major +NAO. The cold anomalies are from -EPO that happens days before. By the end of the run, it's neutralizing and more of a -PNA is trying to build. There is a few day lag between the evolving Pacific pattern and US Temps. It's pointing to an above average 2nd week of Dec. At 384hr you can already see the SE ridge trying to build.