The AO index will come in as the 2nd highest on record for November (1950-present). The two previous highest values (1978, 2013) were both followed by "interesting" winters: the first so-called "polar vortex" winter of 2013-14, and the notorious US/EU winter of 1978-79. pic.twitter.com/zTT0eUxnjp

— World Climate Service (@WorldClimateSvc) November 30, 2020