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

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

Behind the historic winter storm that blasted 40 states this weekend, a dome of Arctic air associated with the polar vortex ...

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

The meteorologists said the polar vortex system is set up due north of Michigan over Canada's Hudson Bay. It's at least ...

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.

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

"Potentially hundreds of thousands of people may go without electricity and heat for days, one meteorologist said ...