Troposphere first starts seeing effects of #SSW on zonal mean circulation, in form of equatorward shifted storm track, ~Feb 15th, 3 days after predicted #SSW. However, forecasts of NAO/AO still have wide spread; models are uncertain at this point about stratospheric influence. pic.twitter.com/FCN0rDcJl2

— Dr. Amy H Butler (@DrAHButler) February 4, 2018