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

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

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

What is the polar vortex? Mississippi weekend weather forecast calls for winter storm with lows in the teens, paired with ...

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. Here's the forecast.

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

A chilling polar vortex is set to bring snow and ice to the South and East this week. We show where.

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

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

The polar vortex is bringing bitter cold and snow to NJ this weekend. Here's the weather forecast, from timing to how much ...

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