A violent thunderstorm ripped through the Washington area late yesterday, triggering power outages, minor fires, street flooding and traffic tieups at scattered points.

Winds gusting to 46 miles per hour combined with torrential rains to disrupt homeward-bound rush hour traffic and knock out electrical power in isolated areas of both the suburbs and the District of Columbia.

Fire departments reported numerous lightning strikes but only few fires, none serious.

Scattered flooding slowed traffic and required rerouting of buses in parts of the District. U.S. Park police closed Beach Drive at Broad Branch Road in Rock Creek Park when the creek went over its banks at about 5:30 p.m.

In Burke, Va., a car driven by Else Mistach of Sterling plunged off a bridge into nine feet of water in Pohick Creek. Mistach, 53, was pulled from the car by Fairfax County firemen and taken to Commonwealth Doctors Hospital where she was admitted for observation.

Both the Potomac Electric Power Co. and the Virginia Electric & Power Co. sent crews out to repair downed wires and damaged equipment. The reported power restored in most areas by nightfall.

The storm, which started at about 4:30 and ended 90 minutes later, dumped .87 inches of rain at National Airport and was accompanied by a dazzling lightning display and brisk winds. The temperature plummeted from 89 to 75 degrees during the storm, bringing some relief from the muggy heat of the last several days.

In the city, Metro reported all subway trains running smoothly but said buses had to be rerouted at 1st Street and Rhode Island Avenue NW because of flooding. D.C. Police reported additional flooding in the 500 and 600 blocks of Rhode Island Avenue NE.

In the suburbs, Fairfax County Police said scattered flooding occurred in Reston, McLean and other areas.

"It's all over the place," said a county police dispatcher.

Fairfax police and fire officials said they received about 50 reports of lightning strikes, but only a few minor fires resulted.

Vepco officials said a total of about 2,500 customers lost power for varying periods in the late afternoon in Arlington, Alexandria and Falls Church. They reported similar outages in the Vienna and Oakton areas of Fairfax County but said early last night they did not know how many families were affected.

Pepco reported 9,000 to 10,000 customers lost power in northwest Montgomery County, the Oak Grove section of Prince George's County and the upper tip of Northwest Washington.

Prince George's County Police said Rte. 1 was closed by flooding at the Calvert, Knox and Guilford roads in the College Park area during much of the rush hour.

The National Weather Service called for more hot, humid weather today with a chance of more thundershowers or storms this afternoon. High temperatures today are expected to reach 87 to 92 degrees.