Violent lightning storms erupted over the Washington area early yesterday, igniting a fire that left a Virginia couple homeless, cutting electric power to more than 9,000 area residents and slicking roads throughout the region.

Two Maryland women died in a car accident on the Eastern Shore that police said may have been weather-related.

Thunderclaps jolted people awake during the worst of the storms, between 11 p.m. Thursday and about 2 a.m. yesterday.

"My home was rocking," said Nancy Moses, a Rockville resident and spokeswoman for Potomac Electric Power Co. ". . . The sound was shaking my house."

The summer steaminess is expected to linger through today, then give way to drier, "more fall-like" conditions on Sunday, according to National Weather Service forecaster Robert Oszajca.

The storms boomed through the region, wreaking scattered havoc, with the heaviest effects felt in Northern Virginia and Montgomery County, Oszajca said.

Trees and limbs were blown across electric lines, cutting power to about 2,000 Pepco customers in the District and Montgomery and Prince George's counties, Moses said.

In Virginia, about 4,800 homes in the Sterling and Herndon areas lost electricity for about an hour around midnight Thursday after lightning struck a Virginia Power substation transformer, utility spokeswoman Peggy Kinchelloe said.

About 2,000 Leesburg area customers lost power for an average of two hours because of broken wires, blown fuses and damaged equipment, Kinchelloe said. Some rural outages lasted up to eight hours, she added.

About 300 other homes in Northern Virginia lost power for about an hour, she said.

The wet roads may have contributed to a fatal automobile accident near Bishopville, on Maryland's Eastern Shore, state police said.

Patricia Anne Petrosino, 24, of Rockville, was driving south on Rte. 113 late Thursday when she lost control of her car and collided with a northbound vehicle driven by Stuart Lee Adams, 40, of Berlin, Md., police said.

Petrosino and a passenger in her car, Debra A. Goldburg, 23, of Silver Spring, were killed, police said. Adams was taken to Peninsula Hospital in Salisbury, where he was treated and released.

Firefighters throughout the area battled blazes touched off by the lightning and responded to fire alarms triggered by electrical problems.

A retired Great Falls, Va., couple lost their home of 41 years to a fire ignited by lightning, Fairfax County fire officials said.

Russell and Betty Hogeland escaped without injury after lightning struck the tarpaper roof of their one-story cinderblock house on Deerhaven Lane at 12:20 a.m.

One firefighter was treated for heat exhaustion, a fire department spokesman said.

According to authorities, other lightning-caused fires:Destroyed a barn in Frederick County, Md., in a blaze that engaged more than 100 firefighters in an all-night battle. Caused an estimated $80,000 in damage to a house on Brink Road in Damascus, Md. Caused damage of about $7,000 to a house on River Oaks Lane in Potomac.

Despite isolated heavy downpours, only 0.21 of an inch of rain fell at National Airport in the 24 hours before noon yesterday. During the same period, 0.91 of an inch of rain was recorded at Dulles International Airport, and 2.4 inches at Baltimore-Washington International Airport.

This region's soggy September had recorded 4.27 inches of rain at National as of yesterday, more than double the norm of 2.02 inches. However, the monthly total is not expected to match the record 17.45 inches recorded in September 1935, the weather service said.