The polar vortex is responsible for the record cold wave that is hitting parts of the U.S.

The Pacific Northwest is expected to see up to seven inches of rain this week, as the eastern United States braces for arctic cold.

Polar vortex systems will bring dangerously cold weather to much of the U.S. this month. Learn how to stay safe, and which ...

More Arctic air is building over northern Canada and will be directed into the United States, courtesy of the polar vortex. How long will the cold waves last? Will it stay cold through Christmas?

Thanks to the polar vortex, the first half of December will bring multiple waves of Arctic air to the U.S. Here's what to ...

Frigid Arctic air is pushing south into the United States, and fortunately, it doesn’t look like freezing temperatures will ...

As one blast of Arctic air pushes out to sea, already a new surge of cold air, driven by a breakdown of the polar vortex, is ...

The Polar vortex is causing temperatures to plummet dangerously across the Philadelphia region, and frostbite could become a ...

A polar vortex broke, and severe temperatures are set to dominate most of the United States, including the Midwest, in the ...

UNITED STATES - With the polar vortex remaining in a weakened, elongated state, a new pulse of Arctic air is expected to ...

Good afternoon and happy Thursday, readers! Temperatures are dropping here in Washington, D.C., with chances of snow tomorrow. If ...

Such events distort the polar vortex, which causes Arctic air to descend into the U.S. and causes temperatures to plummet.