Several days with temperatures of 10-20 degrees below the historical average could be dangerous to plants and ruin outdoor ...

When the polar vortex begins to wobble and allows arctic air to spill south into northern Illinois in January, we usually end up with dangerously-cold air around Chicago. When it happens in April ...

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.

"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 ...

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.