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

This winter, the Northern Hemisphere is suffering from cold waves. In South Korea, an unusually prolonged cold wave has ...

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

Add Yahoo as a preferred source to see more of our stories on Google. Michigan is set for several days of frigid temperatures and heavy lake-effect snow as Arctic air continues its slow march across ...

A crippling winter storm that could paralyze parts of the Southern and Central U.S. this weekend, and some of the effects ...

A Polar vortex has covered the Philadelphia region under a canopy of frigid temperatures, but many people may not realize what a Polar vortex actually is, and the dangers — like frostbite — such ...

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 ...