A collapse in the polar vortex is letting Artic air come here. What that means, and why it happens.

Despite being notorious for bringing brutal cold and dangerous wind chills, the polar vortex has a surprising upside.

The west half of the country, including the Midwest, will start to warm up. But that won't be the case for the East Coast.

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

A severe winter storm that brought freezing rain, sleet and snow to a large part of the U.S. was intensified by the polar ...

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

Similarly, wind chill temperatures measure how cold people and animals feel when outside, measuring the rate of heat loss from exposed skin caused by wind and cold. As wind strengthens, it draws heat ...

Year-round, severe, Artic air is usually kept tightly contained in the North Pole. Arctic wind patterns create a sort of wall ...

Michigan is experiencing frigid temperatures and heavy snow due to a dip in the jet stream, not the polar vortex. The polar vortex is a large-scale cyclone of cold air that typically stays far north ...

The polar jet stream, which is affected by the polar vortex above it, has become quite wavy, allowing Arctic air to ...

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