Forget about the "polar vortex" - it's just November

Fallon’s joke makes a point that Jeff Masters, chief meteorologist at Weather Underground, wants people understand.

“This is just a regular old cold front,” Masters says. “The polar vortex has been around forever. It’s just the media happened to notice it last year, and it’s really not a very scientifically accurate thing to talk about.”

He says the recent popularity of the phrase is misleading. The polar vortex is a constant flow of arctic air circling in the upper atmosphere above the North and South Poles. The cold is usually corralled up there — but sometimes little bits of the arctic air escape.

“It’s just the ordinary sort of weather you expect in winter,” Masters says. “Every now and then you get a big trough of low pressure. It dips down from the pole and it allows arctic air to seep southwards.”