A Polar Vortex will descend on the majority of the United States within the next two days. Temperatures will be unseasonably low with wind chills of below zero. Listen to this story to learn more about the science and rarity of these kinds of vortexes.
Story Length: 4:13
© 2014 National Public Radio, Inc. Used with the permission of NPR. All rights reserved.
AIR DATE: 01/06/2014