The strat. vortex is currently weaker than all other years in the ERA interim record!!!
The zonal mean zonal wind at 10 hPa 60N is today (GFS analysis): -10.5 m/s
Weakest zonal wind at 10 hPa 60N in ERA interim record for todays date is: -5.8 m/s 2013 pic.twitter.com/CemGZ9v0Qw

— PV-Forecast (@PvForecast) January 15, 2021