A round of frigid temperatures is sweeping across much of the United States this week, bringing dangerously cold conditions to millions and setting the stage for widespread disruptions.

The latest blast of frigid air will linger across the central and eastern U.S. through much of the week while another winter storm will dump heavy snow from the Rockies to souther Appalachians.

An Arctic blast tied in part to the polar vortex is driving record frigid air south from the Northern Plains toward the Gulf Coast Tuesday in a cold snap that will last the entire week. Threat level: This event is forecast to set records for the coldest temperatures on record for this late in the season,