1 of 4
Pablo Monsivais, Associated Press
A commuter pulls her wheeled bag through the snow and slush after emerging from the subway at Dupont Circle in Washington, Wednesday, Jan. 26, 2011.

BALTIMORE — Snow, thunder and lightning pounded the Mid-Atlantic Wednesday night, making many roads impassable, with cars stuck on the smallest of hills, and knocking out power to more than 300,000 customers.

Officials urged people to stay off roads, and schools and governments were to be closed Thursday.

In D.C., officials pulled Metro buses off the roads as conditions deteriorated.

At times, portions of major highways, including the Jones Falls Expressway and Interstates 695 and 495, were shut down because of accidents, according to the State Highway Administration.

Fire officials warned the heavy snow was bringing down power lines and causing the outages.

In Baltimore, Mayor Stephanie Rawlings-Blake activated the city's emergency operations center to monitor conditions. The National Weather Service reported that Baltimore received 8 inches of snow in the 24-hour period ending 7:24 p.m.

The SHA and the Maryland Transportation Authority said they had more than 2,200 people working by the heavy traffic made it tough to plow.

Conditions deteriorated rapidly during the evening rush hour in Baltimore, tripling the length of commuters' drives. Visibility was reduced to less than a city block and North Charles Street, the city's main north-south artery, was littered in one block with three MTA buses stuck on a hill and blocking traffic in both directions. Downed power lines disrupted rail travel.

Thunder rumbled, lightning flashed, drivers spun out on turns and were stuck on the slightest inclines.

A year ago, the area, including the nation's capital, was paralyzed by back-to-back storms within a week that dumped more than 3 feet of snow on much of the region. Officials were heavily criticized for the slow response and how long it took to clear the snow.

Baltimore Gas and Electric reported more than 126,000 customers were without power at 10:45 p.m. Wednesday. Spokesman Rob Gould warned residents not to go near downed power lines.

Pepco, which serves Washington and Prince George's and Montgomery counties in Maryland, reported more than 195,000 customers were without power late Wednesday. Pepco came under criticism over the summer when a storm left more than 430,000 customers without power, some for days.

Gould said driving conditions and wind gusts up to 35 mph made it difficult for crews to work at restoring power. He warned that customers should expect extended outages.

In Silver Spring, Md., lightning periodically lit up the snow-filled sky, followed a few seconds later by a rumble or a loud crack. Power lines and tree branches sagged and fell to the ground under the weight of the wet snow.

On Georgia Avenue, a main north-south thoroughfare from Washington into eastern Montgomery County, traffic was almost at a standstill. An ambulance sat still for minutes at a time with its sirens blaring trying to inch its way through the mess, but the cars ahead of it were having a tough time making way. Nearby, plows trying to clear the rapidly accumulating snow were blocked by cars askew spinning their wheels on slippery roads and people trying to push them along.

At First Steps Academy, a daycare in McLean, Va., assistant director Tiffany Metcalf e-mailed parents to let them know that several parents, teachers and children would be staying overnight at the center instead of trying to brave the roads home.

When contacted late Wednesday, a woman who wouldn't identify herself confirmed people were staying there, but wouldn't give details.

Numerous flights at Baltimore-Washington International Thurgood Marshall Airport were delayed or canceled, although a spokesman said some commercial flights were still operating. Dulles International Airport reported all four runways were closed, and Reagan National Airport reported its main runway was closed.

MARC, a commuter rail service, canceled service on the Camden and Brunswick lines for Thursday.