Much of the nation east of the Rocky Mountains is hunkered down for what could be the worst winter storm of the season.

WASHINGTON (AP) — Warm Arctic waters and cold continental land are combining to stretch the dreaded polar vortex in a way that will send much of the United States a devastating dose of winter weather ...

Now, it's got its own catchphrase: the polar vortex, which could be making a return engagement to the U.S. later this month or in January. Or maybe it won't. Regardless, the polar vortex – everyone's ...