jconsor wrote: Iremember a very similar thing being shown in 2023. Also I checked the ECMWF seasonal forecast for Jan 26 and compared into the Jan 23 run, and interestingly enough they show a warmer Atlantic this year by the time we get to spring and early summer.
Excellent point. Also of note is that the ECMWF, as well as the vast majority of the more skillful C3S seasonal models, develop an Atlantic Nino as early as late winter/early spring, which strengthens by June. Note also that most of the same models show significant warming of the Caribbean and MDR between Jan and June.
[url]https://i.ibb.co/N6Wx3yLj/20260112191022-c01ac37c696b9c85866c2e443cc19fafe1451944.png [/url]
[url]https://i.ibb.co/RGwLytdf/20260112191102-cc662742c247770a50945d6e29ed3b5298a84463.png [/url]
[url]https://i.ibb.co/mrbfxWN6/20260112190705-d1395688c586450693fd52a6aff7af123052d199.png [/url]
[url]https://i.ibb.co/dJwKMcfp/20260112190746-c13f45d3e658c3893c071d3e90deb5d8998df23e.png [/url]
[url]https://i.ibb.co/WWb1pRQg/20260112190840-e8bd69c9d07c104c51c58008cc893865eb5a4fce.png [/url]
[url]https://i.ibb.co/RG8ZT3k3/20260112190934-85a31772e2bb9d796b46cb417c24dd63882d4d1a.png [/url]
As many of you are likely aware, a strong Atlantic Nino tends to favor a La Nina developing in the Pacific several months to a half year later. Similarly, an Atlantic Nino can blunt the strength (or at least the atmospheric influence) of a developing El Nino.
Here's a quote from a recent paper:(
https://www.nature.com/articles/s41612-025-01105-w)
"Atlantic Niño, the primary mode of interannual climate variability in the tropical Atlantic Ocean, reaching its peak during boreal summer, is capable of generating cold SST anomalies (SSTAs) in the tropical Pacific.
This occurs through the
strengthening of the descending motion over the eastern tropical Pacific, driven by the ascending motion anomalies over the tropical Atlantic; consequently, the Pacific Walker circulation strengthens during Atlantic Niño, subsequently leading to the development of La Niña in the following winter.Additionally, the influence of Atlantic Niño on La Niña can also occur through driving easterly wind anomalies over the tropical Indian Ocean and the western tropical Pacific as atmospheric Kelvin wave.
Notably, Atlantic Niño may have also played a role in contributing to the recent so-called “triple-dip” La Niña during 2020–2022Aside from the Atlantic Nino and Caribbean/MDR warming, most (5 of 6) models shown in the loop above also show significant warm anomalies developing over the subtropical eastern Atlantic (from near the Canary Islands to off western Europe) by June. An anomalously warm subtropical east Atlantic is typically a strong precursor for significant MDR warming (relative to normal) as the warm SSTs are advected southwest due to weaker than usual trade winds and positive OLR (sunshine) anomalies.
