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

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

The North Pole is surrounded by a massive circular upper-air weather phenomenon in the Arctic called the polar vortex. It is ...

The meteorologists said the polar vortex system is set up due north of Michigan over Canada's Hudson Bay. It's at least ...

Rising Arctic temperatures and melting sea ice could be causing cold air to flow into the Northern Hemisphere. But not all ...

A winter storm descending on the US is expected to deliver heavy snow and ice to more than 150 million people across roughly ...

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

The sudden blast may come as a shock to many Americans after a mostly mild start to winter, but that warmth may be partly ...

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

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