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

A massive winter storm named fern is set to sweep across much of the United States, bringing snow, ice and extreme cold. Over ...

Warm Arctic waters and cold continental land are combining to stretch the dreaded polar vortex in a way that will send much ...

A sprawling winter storm with the potential to become historic is forecast to affect over 235 million Americans across more than 40 states, stretching from Arizona all the way to Maine. The system is ...

Toronto could see one of its coldest nights in years as a massive blast of arctic air spreads across Ontario and other parts of Canada.

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

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

Tens of millions of people are in the path of a major winter storm. Federal cuts threaten efforts to understand the causes of ...