Overview
- Weather models point to a potential sudden stratospheric warming this month, which would be the first November event in the satellite era if it occurs.
- A disruptive warming high over the Arctic can shove the polar vortex south, and temperatures aloft can jump by more than 100 degrees Fahrenheit in a few days.
- Strong coupling between the stratosphere and the lower atmosphere would tilt December into early January toward extended cold and snow across parts of the U.S.
- Weak or short‑lived coupling would favor a milder pattern more consistent with La Niña’s typical influence, especially for the southern and eastern states.
- La Niña helps steer where cold air travels, but the polar vortex largely determines how cold it gets, according to MIT climatologist Judah Cohen.