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.

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

After this weekend's snow storm moves out, cold Arctic air will move in.

WASHINGTON (AP) — Warm Arctic waters and cold continental land are combining to stretch the dreaded polar vortex in a way ...

The majority of the United States will experience chilling temperatures due to a blast of arctic air from Canada. The Midwest ...

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

What is the polar vortex? This article explains what a polar vortex is in simple terms, how it influences winter weather in ...

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 polar vortex is sending Arctic air deep into the United States this week, bringing record-low temperatures to the Midwest and Northeast. From Chicago to New York, forecasters warn of subzero ...

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

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

The polar vortex has broken, and severe temperatures are set to dominate most of the country in the coming days. Temperatures in the 10s are forecast for much of the Northeast, and subzero ...