Regarding the effects of the #SSW on the troposphere, still tons of disagreement. For example, GFS and GEOS-5 are drastically different. The GFS less favorable (+NAM 100-300hPa) while the GEOS-5 has a much more favorable evolution (closer to dSSW, Yu, Karpechko et. al 2017). pic.twitter.com/g0Qn85Hff3

— John Homenuk (@jhomenuk) December 27, 2018