Much below normal temperatures should persist across the eastern U.S. into early February before moderating slightly.

Deep penetration of cold temperatures and a coastal storm will bring bomb cyclone and polar vortex into your newsfeeds.

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

Meteorologist Sven Sundgaard predicted this wacky winter weather back in October, and he explains what's happening now and ...

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

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.

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.

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.

The greater Philadelphia region will experience no weekend letup in the prolonged cold snap gripping the area.

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