Overview
- Multiple forecast models show a major sudden stratospheric warming peaking in late November with stratospheric temperatures about 40 to 50 degrees Celsius above average and slowing winds.
- Long-range guidance currently favors below-average temperatures across parts of roughly 35 states from late November into December, with the most likely surface impacts emerging in early to mid-December.
- NOAA scientists note that changes to stratospheric winds can drive persistent weather shifts lasting weeks, though outcomes vary by event.
- Major November warmings are historically uncommon, with only a few precedents in records since the late 1950s, making this an unusually early occurrence.
- Forecasters stress substantial regional uncertainty—especially in the western U.S.—while the Great Lakes could see enhanced lake-effect snow potential if colder air arrives, warranting close monitoring over the next two weeks.