Profile of mid-latitude (50-80°N) zonal-mean zonal-wind nicely consistent with the downward propagation of the -NAM into the troposphere over the next two weeks. The stratospheric westerlies recover, but the tropospheric jet weakens and zonal-mean surface easterlies appear! #SSW pic.twitter.com/LmMRQgWcgg

— Dr Simon Lee (@SimonLeeWx) January 17, 2019