A lobe of the polar vortex, a ring of freezing air typically ... minus-20 are forecast to reach as far south as Oklahoma and Arkansas — frostbite is possible in less than 30 minutes under ...

The cause of the week-long deep freeze? A polar vortex collapse. Now, meteorologists are calling for another collapse in the middle of March, one that could plunge the U.S., Canada, and parts of ...

An April cold snap is expected to bring unusually cold temperatures to the eastern half of the US next week. The cold snap could impact new spring vegetation and lead to frost in some areas.

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.

An April cold snap is expected to bring unusually cold temperatures to the eastern half of the US next week. The cold snap could impact new spring vegetation and lead to frost in some areas.

"The large polar vortex disruption from the second week of March is playing a key role in next week’s eastern US cold snap," meteorologist Judah Cohen of Atmospheric and Environmental Research told ...