Two newly identified patterns in the stratospheric polar vortex can send cold air over North America to cause extreme cold snaps, but the parts of the country that suffer differ between them. Those ...

The polar vortex, a high-altitude ring of westerly winds that usually keeps Arctic air locked near the pole, is showing signs of unusual weakening. If that circulation falters or collapses, the result ...

Despite a warming climate, bone-chilling winter cold can grip parts of the U.S. In a study appearing in Science Advances, researchers found that two specific patterns in the polar vortex, a swirling ...

Bitingly cold Arctic air keeps pummeling the U.S. with ruthless cold snaps—despite warming winters nationwide. A study explains why: the solution lies far above your head, in the upper atmosphere ...

A Polar Vortex brought temperatures so cold in January 2014 that it froze Niagara Falls. Signals of a rare sudden stratospheric warming in the next two weeks have some forecasting an imminent Arctic ...