It is increasingly likely that a major sudden stratospheric warming -- defined as a reversal of the zonal winds at 10 hPa and 60°N -- will take place, probably between 14 and 17 February. Cautionary note that the GFS seems to be on the extreme end of ensemble solutions, however. pic.twitter.com/limSM0FiEi

— Dr Simon Lee (@SimonLeeWx) February 6, 2023