The storm has caused severe air travel disruptions. According to FlightAware, more than 1,800 flights in and out of the U.S. have been canceled so far, including nearly 500 at Reagan National and more than 250 at Chicago's O'Hare International Airport, which issued a temporary ground stop earlier Monday due to snow and ice.

The first major winter storm of the year that stretched across the U.S. is continuing its deadly journey eastward, where cities in the mid-Atlantic, like Washington, Baltimore and Philadelphia, are now experiencing significant impacts from heavy snow and ice.