Check out those zonal-mean tropospheric easterlies at 60°N, peaking on Feb 8th according to today's 00Z GFS! Associated with this weak tropospheric circumpolar vortex are significant cold-air outbreaks for parts of North America and Eurasia. pic.twitter.com/Z4MtqEii9U

— Dr Simon Lee (@SimonLeeWx) February 3, 2021