Three torrential and sometimes turbulent thunderstorms, fueled by oppressive heat and humidity, erupted over parts of the Washington area yesterday afternoon and evening, knocking out power to well over 24,000 homes and dropping as much as five inches of rain in scattered spots.

Winds gusted up to 45 miles an hour, vivid streaks of lightning damaged a number of homes and pea-sized hailstones rattled on roofs in isolated sections.

National Weather Service forecaster Jeff Bowman said yesterday's high temperature of 95 degrees, which matched the highest reading this year, coupled with the steambath humidity, contributed to the intensity of the storms.

Residents of Darnestown and Olney in Montgomery County and of two locations in Frederick County reported total rainfall that ranged from three to five inches, Bowman said.

The first of the storms, confined principally to Montgomery County, cut off power to about 12,000 homes there, according to the Potomac Electric Power Co. Electricity had been restored to 4,000 or more when the new storms arrived, and power lines, including some that had just been repaired, snapped again.

At one point last night officials reported about 14,000 homes darkened in Montgomery County, principally in the Norbeck, Veirs Mill and Bethesda sections.

Another 10,000 homes were blacked out in Northern Virginia. Most of those outages occurred in the Springfield area, according to Virginia Power.

The first storm reached its peak between 2:30 and 3 p.m., and was followed by another two hours later, which was also confined largely to northern parts of the area. The third, which began about 8 p.m., brought thunder, lightning and rain to the District of Columbia and to Fairfax County as well.

A switch malfunction caused by the storm delayed thousands of evening rush-hour passengers on the Metro subway system's Red Line for about 15 to 20 minutes, according to Metro spokeswoman Beverly Silverberg. She said delays began about 4 p.m. and continued until 6.

Fire officials scrambled to respond to calls from at least a dozen residents calling for help to put out house fires sparked by lightning.

The Kevin J. Donoghue family, 2410 Chilham Place, Potomac, reported flames and smoke on the second floor of their home as a result of the lightning. A bedroom was damaged by the flames, they said.

"If the power is out we will work through the night to restore it, if necessary," said Moses.

Power went out at the Rockville headquarters of the Montgomery County Police Department, stopping office clocks at 3:15 p.m. as officers rushed to answer telephone lines that they could only hear ringing.

"The telephone lights aren't working, so we can't tell which line is ringing," said Officer Phil Caswell. He said he was working in his office with a flashlight.

A cold front that was headed toward Washington last night is expected to make today more pleasant. Morning thunderstorms are possible, Bowman said, but temperatures should not rise out of the 80s.