During winter in the Northern Hemisphere, the polar vortex can often expand and send cold air south, often referred to as an ...

After this weekend's snow storm moves out, cold Arctic air will move in.

This winter’s harsh run is intensifying, with some of the coldest air so far this season plunging into New Hampshire.

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

This winter’s harsh run in the East is intensifying, with some of the coldest air so far this season plunging into Vermont this weekend.

To understand what Americans are experiencing with this winter blast, we need to look more than 20 miles above the surface of ...

The polar vortex is forecast to weaken unusually early, and that could lead to more persistent cold weather in at least parts of the U.S. in December. Last week, almost 100 daily record lows were tied ...

In yet another sign that winter weather is either here or will be soon, the dreaded polar vortex is making news yet again. Its potential arrival in the United States over the next few weeks is cause ...

A shift in the polar vortex has forecasters watching closely as the coldest air of the season approaches. Here's what to know in Georgia this weekend.

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 ...

New York is bracing for the coldest air of the winter this weekend, with snow. Learn how the polar vortex is involved.