2/ The latest GFS polar cap geoptential height forecast shows deepening cold in the polar stratosphere, i.e., a strengthening #PolarVortex. If this couples to the surface, though nothing is guaranteed, it has the strong potential of lights out on a #winter that never even started pic.twitter.com/C5FVlELm0G

— Judah Cohen (@judah47) December 31, 2021