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

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

Temperatures could fall below -20 F across certain parts of North Dakota and Minnesota.

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

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

Have you ever seen a 'steamnado' before? The Texas winter storm caused one to appear over Lake Lewisville on Sunday.

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

Tens of millions of people are in the path of a major winter storm. Federal cuts threaten efforts to understand the causes of such weather.

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

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

Starting Thursday, dangerously frigid air from Siberia and the North Pole is forecast to plunge the Great Lakes region into ...

A dramatic blast of cold air may be coming for the United States in late January, courtesy of the polar vortex. Here's what ...