We have just witnessed the first true sudden stratospheric warming event (SSWE) since January 2013 with a split in the vortex. One piece has pushed over central Arctic Canada and the other into the Europe-Asia border area.

The models went from cold to mild for late February which didn’t coincide with the overall picture. A deeply -AO/NAO and +PNA didn’t suggest a warm East. However, a classic February La Nina pattern IS SUPPORTING warmth, record warmth in the near term from Houston, New Orleans, Atlanta to DC and south into Florida.

MJO is also favourable.

https://twitter.com/Hoosier_Charlie/status/962776023501852672

However in the longer term the models are beginning to turn from mild back to cold LATER FEBRUARY in response to the SSWE. The CFSv2 is firmly on board with a potentially major cold end to Feb and first half is not majority of March for not only the East but much of the nation.

Over the next 7-14 days, the East is warm with records likely to be broken this week, a little less warm next week while the coldest air of the season drives into Montana. That cold over the N Rockies extending into the Central Plains looks to take over.

In the front running 1-7 and 7-14 day, there’s a distinct La Nina-like fight between warm SE ridge and arctic trough over the N Plains.

 

Tags: La Nina, polar vortex, sudden stratospheric warming