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

As the U.S. prepares to take on another bout of cold weather, the term "polar vortex" is getting thrown around. But what is ...

Meteorologists warn that a stretched polar vortex could bring severe winter weather to much of the United States.

A dramatic blast of cold air may be coming for the United States in late January, courtesy of the polar vortex. Here's what ...

Michigan is set for several days of frigid temperatures and heavy lake-effect snow as Arctic air continues its slow march across the eastern U.S.

The polar vortex will push Artic air south, and a severe winter storm could follow. How cold will it get in Louisiana?