The polar vortex, a mass of cold air over the Arctic, is beginning its seasonal strengthening. A strong polar vortex typically keeps the coldest air locked near the North Pole. A weaker or wobbling ...

The United States could be headed for some extreme weather this winter. That’s the early prediction from Severe Weather Europe, a website that tracks weather patterns around the globe. Three factors ...

The polar vortex is stirring up, bringing the earliest hints that the seasons are changing. That shift is most noticeable in northern Wisconsin, where a frost advisory was in effect early Monday, Sept ...

A sudden stratospheric warming event reversed the winds that make up the northern polar vortex on March 9. A new animation shows the vortex also moved away from the Arctic towards Europe. A major ...