2025-2026 ENSO

[donsutherland1]

So far, things have gone pretty much as expected in December. The December 1-10 idea is verifying.

The big question concerning late December is whether the WPO- will weaken allowing unfavorable teleconnections to reshape the pattern. That is a possibility, but isn't certain. Other possibilities also exist. 

[MJO812]

The 12z model runs are once again trending away from a warmup in the long range.  Consistent theme.

[leo2000]

They are too you can see the EPO ridge in Alaska high heights where before there was low heights. This could a trend GEFS 12z shows this. 

[bluewave]

4 hours ago, stadiumwave said:

Some of the AI models are radically different on Day 10. It will be interesting to see which is modeled better.

Models usually don’t get exact timing for the relaxation of a pattern which has persisted for several weeks.

This is why I have been using the general recent climatology in December. Every year since 2011 from Philly to NYC there was at least 1 day reaching 55 or greater from the 17th to the 25th.

That period is still 9-17 days out which is beyond the reliable model skill. It doesn’t mean every day or even most days were this warm since 2011. Some years it was only a 1 day warm up with other years more than a day reaching these temperatures.

But the general December patterns over the years which have had a cold December 1-16th had moderated in the departures from the 17th through the 31st. The degree of this moderation has also been variable. 

 

[stadiumwave]

From Paul Roundy:

"Base state supports Bering Strait and Greenland blocking, with troughing in the eastern US. A fast component of the MJO signal moves through Indian basin to Maritime Continent 15-30 Dec offsetting the cold eastern US signal and potentially forcing a period of warm anomalies in the eastern US."

 

[bluewave]

3 hours ago, donsutherland1 said:

So far, things have gone pretty much as expected in December. The December 1-10 idea is verifying.

The big question concerning late December is whether the WPO- will weaken allowing unfavorable teleconnections to reshape the pattern. That is a possibility, but isn't certain. Other possibilities also exist. 

I suspect that the issues the models have been having long range are related to the much faster Northern Stream of the Pacifc Jet which continues. It’s not typical to get a strong -WPO +EPO couplet  at the the same time in December. So the shortwaves in the fast Pacific flow are lowering heights over Eastern Alaska while the -WPO ridge stands firm.

At least into mid December the +EPO and stronger Pacific are trying to have the ridge roll out into the Plains while the -WPO would have the ridge axis more in the West. So a tug of war between two competing influences that we normally don’t see at the same time.

My guess is that the ridge eventually comes east at some point during the 2nd half of December as the Pacific Jet eventually wins out in these situations. Notice how the 10 year December strong -WPO composite features a more -EPO and a relaxed Pacific Jet.
 

Much stronger Pacific Jet and unusual +EPO in mid-December for a very strong -WPO block

Past 10 strongest December 500 mb -WPO blocks didn’t have to compete with such a strong Pacific Jet and +EPO

 

 

 

[bncho]

11 minutes ago, Eskimo Joe said:

 

 

thoughts y'all? i'm not saying it'll happen or not i'm just curious and your takes