Today's @ECMWF extended-range forecast of the 10 hPa 60°N zonal-mean zonal wind shows an ensemble-mean prediction of a major #SSW in the first week of January. Merry Christmas! https://t.co/KRHCet96fU pic.twitter.com/JVmvndbupQ

— Dr Simon Lee (@SimonLeeWx) December 24, 2020