polar vortex
Definition
A large-scale, persistent area of low pressure and cold air encircling one of the Earth's polar regions, typically in the stratosphere or troposphere.
In meteorological contexts, particularly North American weather events, it refers to the southward intrusion or dip of this Arctic air mass, causing extreme cold snaps and blizzards in mid-latitudes.
Examples
The polar vortex turned my morning commute into a real-life game of 'don't slip on ice or become a human popsicle'.
Blame the polar vortex for why my coffee froze solid before I could even sip it – winter's revenge on caffeine addicts.
When the polar vortex hits, even the squirrels start hoarding parkas instead of nuts.
Surviving a polar vortex means layering up so much you waddle like a confused penguin at a beach party.