At one point Tuesday, more than 36,000 Allegheny Power customers in Maryland, West Virginia and Pennsylvania were without power, Beck said.
Beck said restoring services to everyone was a difficult job because of the wide area affected.
"Some customers' (service) may be restored tonight, but there are some customers that we won't be able to restore until tomorrow afternoon. Our focus is to restore the services as soon as possible," Beck said.
A storm caused problems earlier Tuesday in Jefferson County, W.Va.
Lightning knocked out the radio system at the West Virginia State Police headquarters in Bardane, W.Va., at about 10:30 a.m., according to 1st Sgt. Deke Walker. It was believed the radio service was disrupted when lightning struck a radio tower in back of the building or the barracks itself, Walker said.
Radio transmissions were temporarily handled out of the state police barracks in Martinsburg, W.Va., Walker said. Radio service was back in operation late Tuesday afternoon, police said.
When the second storm hit in the afternoon, trees fell on power lines across Jefferson County, emergency dispatchers said.
Arcing lines fell in front of a day-care center on Cheney Street in Bolivar, W.Va., according to a Friendship Fire Co. spokesman. Firefighters escorted parents past the lines and into the building so they could safely get their children, the spokesman said.
Four people were floating in inner tubes on the Shenandoah River when the storm struck, according to Lenny Lehman, ambulance chief for the Blue Ridge Fire Co. One of the tubers got stuck on a rock near the Bloomery Bridge but was helped to the edge of the river by a whitewater rafting crew, Lehman said.
During the afternoon storm, lighting struck at 14437 Hicksville Road in Clear Spring. No injuries or fires were reported as a result of the strike, according to Washington County Emergency Services dispatcher Scott Wolff.
Heavy wind knocked trees onto houses at 20111 Marble Quarry Road and 6234 Appletown Road, both in Boonsboro, Wolff said.
There were wires down in nearly every part of the county, "from Hancock to Boonsboro," but no reports of injuries, Wolff said.
"We had about 50 calls all at one time," Wolff said.
Local weather observers said .82 of an inch of rain fell in Hagerstown, .56 of an inch in Martinsburg and .90 of an inch in Waynesboro, Pa.
Weather observer Pat McCusker of Clear Spring said wind gusts reached 62 mph Tuesday and reported 0.85 inches of rain there.
McCusker said a bolt of lightning hit his weather station, destroying about half of it.
Staff writers Dave McMillion and Don Aines contributed to this story.