The extreme weather is being caused by the polar vortex, an area of cold air that circulates around the Arctic.

Kentucky, Virginia, West Virginia, Kansas, Arkansas, and Missouri have declared states of emergency as the storm brings dangerous travel conditions.

Millions of Americans from the Ohio Valley to the mid-Atlantic are bracing for a wintry Monday with heavy snowfall, ice, rain and storms, which are forecast to disrupt morning commutes and snarl airline schedules across the East Coast.