polar vortex

polar vortex (plural polar vortexes or polar vortices)

1. A large-scale cyclone located in the middle and upper troposphere and stratosphere that surround the polar highs and lay in the wake of the polar front.
   • 2019 January 22, Richard A. Oppel Jr, “Had Enough of Snow? Try Frost Quakes, Waterspouts and Bitter Cold”, in The New York Times‎, →ISSN:

     Experts pointed to several factors. One culprit: the polar vortex, a giant mass of cold air normally contained above the North Pole by strong bands of circulating winds. In recent weeks, the vortex has broken apart, with one block of cold air escaping into Canada and the United States, and another into Europe.