2025-2026 ENSO

[GaWx]

Here’s the latest GLAAM forecast: Ninoish

[Stormchaserchuck1]

SOI data is reliable and goes back to the 1800s. Here's the top 9 positive SOI Fall/Winters minus negative SOI Fall Winters 1900-1950.. fits our post-1950 composite. In other words, this image below is the typical La Nina state 1900-1950. 

 

March included

Here's precip

[Stormchaserchuck1]

1 hour ago, GaWx said:

Here’s the latest GLAAM forecast: Ninoish

Wonder if we'll finally break this strong +AO pattern, that has been there since May..

[michsnowfreak]

6 hours ago, yoda said:

Hope this hasn't been posted yet, if so my mistake... saw this new study this morning.  Looks interesting and will be reading... but I appreciate any thoughts by our experts here

https://www.google.com/amp/s/phys.org/news/2025-07-polar-vortex-patterns-shifting-winter.amp

https://www.science.org/doi/10.1126/sciadv.adq9557

 

Interesting read, and this has actually been mentioned by @Stormchaserchuck1 and myself before. For instance, this line: "As winters in the United States continue to warm on average, extreme cold snaps still manage to grip large swaths of the country with surprising ferocity."

In discussing some of the arctic outbreaks of recent years, the usual posters are very quick to try and put out the discussion  before it gets started, citing the mean winter temp in the U.S. and/or the cold/warm ranking of the mean temp of winter for the entire U.S., as if that takes away the arctic outbreaks. 

Some years have seen outbreaks in areas that are far more severe than at any time during past winters with an overall colder mean temp in that same area.

[donsutherland1]

59 minutes ago, michsnowfreak said:

Interesting read, and this has actually been mentioned by @Stormchaserchuck1 and myself before. For instance, this line: "As winters in the United States continue to warm on average, extreme cold snaps still manage to grip large swaths of the country with surprising ferocity."

In discussing some of the arctic outbreaks of recent years, the usual posters are very quick to try and put out the discussion  before it gets started, citing the mean winter temp in the U.S. and/or the cold/warm ranking of the mean temp of winter for the entire U.S., as if that takes away the arctic outbreaks. 

Some years have seen outbreaks in areas that are far more severe than at any time during past winters with an overall colder mean temp in that same area.

Good studies. I suspect that the warming of the West Pacific is having an impact on the polar vortex. Arctic outbreaks remain possible and it is plausible that they can, at times, penetrate farther south than they had in the past.

However, because the deep cold pool is smaller than it was prior to 2000, in general, the cold shots tend not to be as expansive or as prolonged as they once were absent a "stuck pattern." That's why the overall coverage of cold anomalies is typically less than it was during earlier winters (e.g., February 1979 vs. February 2015) and the only nationwide winter among the top 30 coldest winters among the 2000s was 2009-10. 

[GaWx]

4 minutes ago, donsutherland1 said:

Good studies. I suspect that the warming of the West Pacific is having an impact on the polar vortex. Arctic outbreaks remain possible and it is plausible that they can, at times, penetrate farther south than they had in the past. However, because the deep cold pool is smaller than it was prior to 2000, in general, the cold shots tend not to be as expansive or as prolonged as they once were absent a "stuck pattern." That's why the overall coverage of cold anomalies is typically less than it was during earlier winters (think February 1979 vs. February 2015). 

Thanks Don.

 But as 30 year “normals” also rise, shouldn’t the cold anomaly coverage in cold shots at least in theory be as expansive as before?

[donsutherland1]

5 minutes ago, GaWx said:

Thanks Don.

 But as 30 year “normals” also rise, shouldn’t the cold anomaly coverage in cold shots at least in theory be as expansive as before?

In theory, yes. But the Arctic is warming faster than the mid-latitudes and the deep cold pool is shrinking. That’s reducing the coverage of fold anomalies even against a warmer baseline.