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

Across the United States, winter storms are colliding with a warmer atmosphere and a disrupted Arctic, turning familiar ...

An unusually brutal winter storm is set to pummel more than 160 million Americans from Friday, as a stretched "polar vortex" ...

The sudden blast may come as a shock to many Americans after a mostly mild start to winter, but that warmth may be partly ...

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.

Much of the nation east of the Rocky Mountains is hunkered down for what could be the worst winter storm of the season.

The frigid temperatures, massive snow and deadly ice storm taking shape east of the Rockies might seem to conflict with life on a rapidly warming planet. But all of these things still happen, even ...

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

The term "polar vortex" has gained popularity in recent years, but the phenomenon itself is not new. According to the U.S. National Weather Service, the polar vortex refers to the counterclockwise ...

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

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

About 230 million people will face temperatures of 20 degrees or colder and about 150 million likely will be hit by snow and ...