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."