As frigid winds and mammoth snowfall battered the U.S. this past week, a now-familiar item in our weather lexicon returned: the “polar vortex,” a large low-pressure zone that can push a mass of cold air down from the North Pole to more temperate climes.

It’s safe to say that few people, outside of hard-core meteorology nerds, had heard of the “polar vortex” before last January. When meteorologists identified an Arctic front as the culprit behind the record-breaking cold wave that struck North America, the term appeared in...