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 ...

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

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 ...