The polar vortex in the stratosphere broke up, which caused the movement of cold Arctic air towards southern latitudes, ...

Much of the U.S. has seen a major dip in temperatures combined with winter storm conditions over the weekend, thanks to an expansion of the polar vortex—the area of cold air that circulates ... to ...

Spring may have technically sprung in the Northern Hemisphere, but the lingering impact of the collapsing polar vortex could ...