Workers prepare to treat the steps of the U.S. Capitol with ice melting salt in Washington January 22, 2016. [Photo/Agencies]

Steady snow was falling on southeastern Pennsylvania, including Philadelphia, early on Saturday. The storm is forecast to head north toward New York City later in the day.

Record Breaker? 

The National Weather Service said it was too soon to tell whether the snowfall will break records around Washington D.C. and Baltimore. "Either way, we're looking at a significant event," said NWS meteorologist Frank Pereira.

The full force of the storm could dump enough snow on Washington to eclipse the 17.8 inches (45.2 cm) of a 2010 storm and total snowfall might rival the storm of 1922, when a record 28 inches fell.

The storm developed along the Gulf Coast, dropping snow over Arkansas, Tennessee and Kentucky on Friday. On the East Coast, warm, moist air from the Atlantic Ocean collided with cold air to form the massive winter system, Pereira said.

"This has life-and-death implications and all the residents of the District of Columbia should treat it that way," Washington Mayor Muriel Bowser said.