The displaced polar vortex will bring prolonged periods of cold to the eastern portion of the Lower 48 through the end of January.

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

Cold temperatures are expected to last through the end of the month — and forecasters say that there's a potential for snow in Florida this weekend ...

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.

The polar vortex will push Artic air south, and a severe winter storm could follow. How cold will it get in Louisiana?

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.

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

It exists all the time, but it usually gets stronger in winter. When the jet stream (a river of wind) bends and dips south, ...

Alabama braces for another polar vortex blast bringing well below freezing temperatures. How cold will temperatures get? Here ...

Michigan is experiencing frigid temperatures and heavy snow due to a dip in the jet stream, not the polar vortex. The polar vortex is a large-scale cyclone of cold air that typically stays far north ...