Blizzard conditions are expected in some areas until the morning when the storm spins out to the Atlantic.
Thursday will be very windy with gusts as high as 45 miles per hour.
The total snowfall in many areas will be more than a foot of snow. That's on top of the more than two feet of snow that buried parts of the Mid-Atlantic last week.
This winter is the snowiest on record in many places - forehead-high snowfall in Baltimore, Philadelphia and Washington.
It's been a stormy winter for the Mid-Atlantic. There's no single reason but a major influence has been a cooler Pacific Ocean.
That's pushing cold air from Canada deep into the United States.
Storms are tracking along the jet stream toward the Mid-Atlantic states rather than along the Eastern seaboard.
The pattern could stick around for years.