A powerful storm that crept across the country is dumping a mix of snow, freezing rain and sleet on the Mid-Atlantic region and is headed northeast, threatening as much as a foot of snow in sections of Delaware and New Jersey and raising concerns about a messy morning commute.

The storm covered the fields of the Philadelphia Eagles and Pittsburgh Steelers with white and forced the cancellation of thousands of flights across the U.S. The storm is slowing traffic on roads, leading to a number of accidents, including a fatal crash on the Pennsylvania Turnpike near Morgantown that led to a series of fender-benders involving 50 cars.

The forecast is calling for the wintry mix to continue through Sunday, turning to rain early Monday.

The National Weather Service says snow accumulation in some sections of Delaware and southern New Jersey could reach 9 to 11 inches.