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

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 North Pole is surrounded by a massive circular upper-air weather phenomenon in the Arctic called the polar vortex. It is ...

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

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 ...

When the polar vortex breaks, Artic air come south. Here's what to know right now.

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 ...

Water, salt, and heat all get mixed within eddies with important climate consequences, but the boundary of an eddy is hard to ...