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.

A powerful winter storm covered the East Coast Monday, leading to thousands of cancelled flights and hectic airport terminals. The weather originated in the Rocky Mountains before travelling eastward,

Bone-chilling cold and wind chills are expected, with temperatures dropping to 12 to 25 degrees below normal in some states.

A major winter storm has brought heavy snow, sleet and freezing rain from the Midwest to the mid-Atlantic region, causing thousands of flight cancellations and school closures and leaving hundreds of thousands without power.