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

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

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

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

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

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 ...

Major cities across the Northeast and Midwest are facing temperatures 10-20 degrees below average, according to forecasters.

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

A Polar Vortex brought temperatures so cold in January 2014 that it froze Niagara Falls. Signals of a rare sudden stratospheric warming in the next two weeks have some forecasting an imminent Arctic ...