A car drives through standing water as it turns from Contee Road onto Baltimore Avenue after heavy rain on Saturday in Laurel. (Mark Gail/FOR THE WASHINGTON POST)

High winds and furious rains raced across the Washington region at the end of a muggy Saturday afternoon, causing power outages that left tens of thousands of homes and businesses in the dark and intersections without working traffic lights.

At least one tornado touched down in the Reston-Herndon area about 4:30 p.m., Fairfax County spokesman Jeremy Lasich said. Initial reports indicated the storm caused only minor injuries.

Officials sent out alerts urging people to seek cover as violent weather arrived. The rain pounded with a ferocity amid winds that exceeded 60 mph. Many trees were toppled and temperatures plunged from the 90s to the 60s. As the storm sped eastward, affected areas saw relative calm return after about 15 minutes.

The District ended up canceling a flash flood warning as driving rains moderated to showers. The Bay Bridge across the Chesapeake Bay was shut down due to wind restrictions, but quickly reopened.

Despite the storm’s brevity, the damage was widespread.

By Saturday evening, 188,000 customers across the region were without power. All the most populous jurisdictions were affected — Fairfax, Prince William, Prince George’s and Montgomery counties, as well as the District.

Among the hardest-hit jurisdictions was Alexandria, where 30,000 customers lost power. Power lines and trees were down there as well as in Loudoun County, said Dominion Power spokesman Richard Zuercher.

In Fairfax, outages shut down traffic signals at major intersections. More than one in 10 Fairfax residences lost power, Fairfax officials said late Saturday afternoon.

The storm sent trees falling onto two townhouses and an apartment complex in the county. Fire and rescue officials said one person suffered minor injuries.

Many people were caught unawares as the storm sped in and heavy raid began to fall. Streets quickly became deserted as pedestrians, wearing only light clothing suitable for a sweltering day, scrambled for cover.

Crystal City residents Kevin and Cathy Burke had pedaled under sunny skies all afternoon around the Lincoln Memorial.

When dark storm clouds formed to the west, they decided to cut their bike ride short and head for Virginia. But high winds and pelting rain caught up with them near Reagan National Airport, sending them rushing for the only shelter in sight, a tree along the George Washington Parkway.

“I felt a few raindrops on the Memorial Bridge, but then it came from nowhere,” said Cathy Burke, 52.

When the storm dwindled, many residents emerged from their homes to find large tree limbs lying across their houses and cars.

On Ontario Place NW in the District, a gust of wind snapped a tree trunk at its base. The tree fell across the street, its crown blocking access to two residences.

The lower part of the trunk fell squarely onto a pickup truck, but damage was limited to a few dents. The car behind the pickup was enveloped in branches, but appeared to have avoided damage, to the relief of its owner, Lori Lodes.

“It takes a catastrophe to bring out the neighborhood,” said Lodes, observing that neighbors who had not known each other were suddenly commiserating and swapping jokes.

Utilities that were criticized for their slow response to previous storms this summer took steps Saturday to prepare for the storm.

Pepco said it had called in extra linemen and tree trimmers and planned to have an emergency call center running into the night.

The storm was part of a broad swath of fierce weather battering the northeastern part of the country, extending along the Eastern Seaboard from the mid-Atlantic to Maine.

In New York City, a tornado touched down in a beachfront neighborhood in Queens, and the threat of worse weather caused officials to postpone the women’s final of the U.S. Open tennis championship until Sunday. In Buffalo, strong winds blew roofs off buildings.

Anne Midgette, Jenna Johnson and Clarence Williams contributed to this report.