Federal government offices and schools in the Washington, D.C., area were closed on Monday as the region received its first significant snowfall of the season, part of a winter storm that left more than half a million customers without power as it moved up the East Coast.
“A major winter storm is underway,” the National Weather Service said on Monday morning, while warning, “Snow-covered and slippery roads along with heavy snowfall and low visibility will make travel dangerous.”
The storm dropped more than 14 inches of snow in parts of Northern Virginia, while Washington recorded more than eight inches, according to the Weather Service. In central Tennessee and northern Alabama, which caught the tail end of the storm, snowfall totals reached nine inches, the Weather Service said.
The storm was moving north on Monday afternoon through Maryland, Northern Delaware and Southern New Jersey, where snowfalls totals ranged from six to 15 inches. The weather system was expected to pull offshore by about 10 p.m., Andrew Orrison, a meteorologist with the Weather Service in College Park, Md., said.
In North Carolina, the storm brought strong winds and snow to the mountains in the western part of the state, while up to two inches of rain fell in Greensboro, Raleigh and Durham, breaking daily records for rainfall set in 1992.
As of Monday night, more than 340,000 customers in Virginia were without electricity, while outages affected 43,000 customers in North Carolina and more than 42,000 in Maryland, according to PowerOutage.us, which aggregates data from utilities across the United States.
Hundreds of flights from Washington-area airports were canceled or delayed on Monday morning, according to FlightAware, which tracks the status of flights. The Atlantic City International Airport temporarily closed on Monday while crews worked to clear runways of snow, according to the New Jersey Department of Transportation.
At a news conference on Monday, Mayor Muriel Bowser of Washington said, “I can’t emphasize enough right now that you should stay home.” A snow emergency was in effect for the city until 7 p.m. Monday.
Gov. Larry Hogan of Maryland mobilized state resources, and Gov. Philip D. Murphy of New Jersey declared a state of emergency for five counties, warning residents to stay off the roads. In Delaware, state government offices were closed.
At a news conference, Governor Murphy said that as of Monday afternoon, emergency workers in his state had assisted 245 motorists.
“Stay off the roads,” he said. “Let this thing get cleaned up over the course of the evening, and then hopefully get a fresh start commute in the morning.”
Roads in the region became treacherous. The Virginia State Police said on Monday that its officers had responded to more than 650 reports of crashes and assisted more than 600 stranded vehicles as of 4 p.m. Some drivers had minor injuries, but no deaths were reported, the authorities said.
“The cars are going too fast for conditions, and they’re sliding off the roads, into ditches, into the cement walls, into one another,” said Corinne Geller, a spokeswoman for the Virginia State Police. Rain on Sunday prevented crews from properly salting the roads, she said, making highways more dangerous during the snow on Monday.
In Washington, Ms. Bowser said on Monday that residents should stay off the “very slick and hard-to-pass” roads.
Crews were working to remove snow from the roads in the affected states on Monday afternoon, after the worst of the storm had passed. Several agencies posted images of cars stuck on snow-covered roads, which officials urged residents to avoid so snow plows could clear the streets.
“Stay off the roadways, so our crews can safely do their jobs,” the Maryland Department of Transportation said.
Schools across the Washington region canceled classes on Monday, as did several in the Richmond area in Virginia. In New Jersey, some systems announced closures while others said they would operate with delayed openings.
The heaviest snow, at two inches per hour, occurred right after the transition from rain on Monday morning, meteorologists said. Mr. Orrison of the Weather Service said that there were reports of thundersnow — a phenomenon when thunder and lighting occur during a snowstorm — in the Washington area on Monday.
The possible refreezing of melted snow in the evening and overnight hours could lead to additional travel concerns.
With the possibility of black ice and slick roadways, the Virginia Department of Transportation told residents on Monday night to avoid travel, and the Maryland Department of Transportation told drivers to delay their commutes on Tuesday morning.
“The refreeze on the road could definitely be dangerous for commuters on Tuesday morning,” Mr. Orrison said.
Jesus Jiménez contributed reporting.