US government offices are closed as the East Coast braces for a blizzard that dumped heavy snow on Midwestern states in recent days.
Schools were shut and more than 1,500 flights cancelled at Washington DC and Baltimore airports, though by late afternoon little snow had accumulated.
About 200,000 customers have no power in the mid-Atlantic region between New England and the south-eastern states.
On Tuesday, Chicago saw heavy snowfall with about 10in reported in some areas.
The governor of Virginia declared a state of emergency after about 170,000 people lost power in the state; 50 members of the National Guard were sent to clear roads.
Many people were allowed to leave work early, as snow and slush blanketed the streets.
But in Washington DC, despite persistent rain there was little snow on the ground by Wednesday afternoon.
Outside the cities, snow had reportedly been falling since about 03:00 local time (08:00 GMT).
In the state of Maryland, by Wednesday morning about 600 homes and businesses had lost power and motorway officials encouraged residents to keep off the roads.
"We're urging folks not to travel today and to leave the driving to our professional snow plough drivers," a Maryland transport spokeswoman said.
Maryland officials stationed tow trucks at motorway rest areas and car parks, and tree-trimmers were on standby in anticipation of the storm.
Mid-Atlantic utility companies also had extra repair crews on duty to deal with outages.
In Virginia, as much as 12in of wet snow were forecast to hit coastal areas, while the inland Blue Ridge Mountains and other mountainous areas could receive as much as 21in.
Emergency officials in New Jersey said they were monitoring a coastal storm, expected to bring lashing rain, wind, snow and possibly coastal flooding to the region hit by super-storm Sandy in October.
The last major snowstorm to hit the mid-Atlantic, in January 2011, was dubbed "snowmageddon", dumping about 5in of snow in Washington DC and 7.5in in Baltimore.
It triggered overnight traffic jams and took out power to about 320,000 homes. It is also blamed for causing six deaths.
The snowstorm arrives in the mid-Atlantic region after pummeling Chicago and the Midwest.
On Tuesday, schools were cancelled across Wisconsin, Minnesota and Illinois, and as much as 9in of snow was reported at Chicago's busy O'Hare airport by midnight.