The Washington area was battered last night and this morning by heavy downpours that produced transportation snarls on roads and rail alike.

Shortly before 4 p.m., the National Weather Service said the area appears to be out of the eye of the storm as most of the precipitation moved further east. It cancelled a flash flood watch that had been in effect for the Baltimore area, Anne Arundel County, Prince George's County, Calvert County, Harford County, Charles County and St. Mary's County.

Nonetheless, the soggy conditions left from the earlier two days of storms had left a mark.

Flooding at the Silver Spring station knocked out the automatic train control this morning for the stretch of track between Glenmont and Silver Spring. That forced train operators to manually run the trains, which significantly reduces their speeds. Red Line trains were operating every 10 minutes between Glenmont and Fort Totten stations.

Metro workers spent the morning clearing water from the flooded areas at the Silver Spring station and have been repairing or replacing affected electronic equipment.

Shortly after 4 p.m., Metro officials said they had restored about 80 percent of service on the section of the Red Line that was affected by flooding this morning. Trains this evening will be running about every six or seven minutes between Forest Glen and Takoma. The normal pace is every five minutes. Metro riders should not notice the difference, said Steve Feil, Metro's chief operating officer for rail.

Trains on the Manassas line of the Virginia Railway Express were also delayed this morning, running up to an hour late because of speed restrictions on the railroad, which ran along several creeks swollen with water, spokesman Mark Roeber said. One train, #334, had to be turned around at the Burke station and returned to Manassas, he said. A handful of passengers were on that train and were able to transfer to OmniLink buses for the remaining trip to Washington, he said.

Afternoon service on the VRE is expected to return to normal, he said.

The storms caused major delays on roads this morning, some of which were impassable because of pavement buckling or high water or downed power lines or debris -- or all of the above.

Virginia transportation officials said that flooding on Interstate 66 began yesterday around 10 p.m. and by midday today the left hand lane on the westbound road near Route 7 was still closed. The backups in the morning stretched to Rosslyn.

The problem was caused by debris that had blocked a storm drain and caused up to six feet of water to build up, but officials cleaned up the debris and reopened the road after 2 p.m. They expected the evening rush hour to be normal.

The overnight deluge had caused extensive traffic backups across the region this morning as water washed away many roads and discarded debris on others -- a situation made worse by failures on Metro and other transit lines.

"At a time when roads don't work and then mass transit also doesn't work, there's not much left for commuters," said Lon Anderson, spokesman for AAA Mid-Atlantic.

Anderson said the saving grace was that the storm came in the middle of the summer travel season when many workers are out of town. "Thank God it wasn't after Labor Day, then we would have been really up a creek."

During the night, trapped motorists were rescued from swirling floodwaters in several spots, houses were struck by lightning and many roads were closed as fierce thunderstorms pelted the Washington area.

The storm flooded basements, forced evacuation of apartments and disrupted airline schedules.

With rain falling in places at a rate that meteorologists estimated at two to three inches an hour, water rose swiftly on many thoroughfares, including Swink's Mill Road in McLean, East West Highway and Sligo Creek Parkway in Montgomery County and New Hampshire Avenue in Prince George's County.

At the National Zoo, a zoo police officer was rescued late last night by D.C. emergency personnel after he was trapped by water that reached the windows of his private car.

Rescuers extended a ladder and pulled him from the car about 10:15 p.m. after outfitting him with a flotation device, said fire department spokesman Alan Etter.

Two people were rescued from a car on Rock Creek Parkway near Massachusetts Avenue NW, and two other vehicles veered from the parkway into Rock Creek near Park Road NW, Etter said.

At least one auto was swept downstream as Sligo Creek surged over its banks in the Silver Spring area, said Pete Piringer, a spokesman for the Montgomery County fire and rescue service. Areas near the creek in Prince George's County also flooded.

Flights to all three of the Washington region's major airports were delayed or canceled. A Federal Aviation Administration Web site showed that flights scheduled to arrive in the area were being held on the ground at their points of origin.

In Baltimore, protective material intended for a painting project on the city's Francis Scott Key Bridge blew down, forcing the bridge to close.

Sweeping across the Washington region after a day of oppressive humidity, the storms inundated streets in low-lying areas, from Richmond in the South to Harford County, Md., in the north, and across to the Eastern Shore. The storm system also brought pouring rain to New Jersey and eastern Pennsylvania, where as much as six inches fell yesterday, according to the National Weather Service.

In the Washington region, flooded thoroughfares were reported in Calvert and St. Mary's Counties in southern Maryland, in Dorchester County on the Eastern Shore and in Baltimore.

In Prince George's, the impact appeared most severe in western and northern sections, including Adelphi, Beltsville and Laurel. Motorists were pulled from floodwaters at New Hampshire Avenue and Piney Branch Road. Water flooded the basements of at least half a dozen houses in the 8400 block of New Hampshire Avenue, said Prince George's fire department spokesman Chauncy Bowers.

Residents of at least four apartments in a building on Morris Drive in Laurel were forced to leave because of flood damage, Bowers said.

The full force of the storm began to be felt about 8 p.m., as sheets of rain began to soak lower Montgomery County and Upper Northwest Washington. Within the next hour or two, rescuers were dispatched to aid stalled motorists in Montgomery at such spots as Massachusetts Avenue at Little Falls Parkway, where three people were extricated from high water.

In Silver Spring, where Sligo Creek overflowed, rescuers saved a motorist who was in a car that, impelled by the force of the fast-moving water, "continued downstream," Piringer said.

Rescues also were made on River Road in the Somerset area, where three people who had been in two cars were brought to safety, he said.

Emergency personnel also went to the aid of motorists on Georgia Avenue near the Capital Beltway and on New Hampshire Avenue and Colesville Road near Sligo Creek, as well as on East West Highway and on Carroll Avenue near Long Branch Parkway.

No injuries were reported to those who escaped stalled cars, some with the aid of boats brought by swift-water rescue teams. However, Piringer said passengers were injured in several collisions elsewhere in the county.

He said several structures in Montgomery were reported hit by lightning. Damage was estimated at several hundred thousand dollars at a house in the 18200 block of New Hampshire Avenue in the Ashton section, Piringer said.

Flash flood warnings were issued last night for much of the area. They materialized in the middle of the morning rush hour, sweeping down from the north and west.

Washington Post staff writers Steven Ginsberg, Lyndsey Layton and Clarence Williams contributed to this story.