A collapse in the polar vortex is letting Artic air come here. What that means, and why it happens.

Year-round, severe, Artic air is usually kept tightly contained in the North Pole. Arctic wind patterns create a sort of wall ...

Add Yahoo as a preferred source to see more of our stories on Google. The polar vortex has broken, and severe temperatures are set to dominate most of the country in the coming days. Temperatures in ...

Here’s the wind chill chart. Notice the four shadings, indicating how long it will take for frostbite. When we get to wind ...

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

As a winter storm approaches Western North Carolina and other regions, here's what to know about deciphering forecaster terms.

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

Michigan is set for several days of frigid temperatures and heavy lake-effect snow as Arctic air continues its slow march ...

The "polar vortex" talk becomes really popular each year. It usually doesn't surface until winter. Still, this season, the eastern U.S. is getting a shot of frigid air as this infamous polar vortex ...