Up to 21 inches (53 cm) of snow had fallen by 6 a.m. EST (1100 GMT) in suburban Washington, D.C. Local weather forecasters said the storm could bring the heaviest snowfall in 90 years to the Washington area.
Strong winds caused blizzard conditions, especially along the mid-Atlantic coast, with gusts up to 40 miles per hour (64 kph).
Most flights were canceled on Saturday at the Washington-Baltimore area's three main airports and at Philadelphia International Airport.
Driving in the region was treacherous and authorities advised motorists to stay off the roads.
Washington's Metro train service will operate only underground on Saturday and bus service has been canceled.
Amtrak canceled a number of trains operating on Saturday between New York and Washington and also between Washington and some destinations to the south.
More than 120,000 homes lost power in the Washington area as the wet and heavy snow weighed down trees and power lines.
stay warm all