A fresh blast of Arctic air is poised to spill across a wide swath of the United States, and the latest polar vortex map ...

Temperatures could fall below -20 F across certain parts of North Dakota and Minnesota.

Major cities across the Northeast and Midwest are facing temperatures 10-20 degrees below average, according to forecasters.

What is the polar vortex? Mississippi weekend weather forecast calls for winter storm with lows in the teens, paired with freezing rain, sleet and snow.

This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated. As we head into a more active weather ...