Thunderstorms Roll Through Region, Dumping Record Rain

Records were set or matched in at least one part of the Washington region Friday for two of the meteorological features that make summer what it is: heat and rain.

At Dulles International Airport, the temperature reached 94 degrees, making the day one of the warmer ones this summer and matching the record for August 21, which was set in 2005.

But the day could not remain that warm for long. As thunderstorms popped up and rolled across the region throughout the afternoon and into the night, at least three of them deluged Dulles and its surrounding area.

"Wow," wrote a contributor to washingtonpost.com's Capital Weather Gang blog. "That was quite a long period of rain here in Sterling [which is in the neighborhood of the airport]. "It's been a long time since I've seen that much rain."

Indeed, by about 10 p.m. the three thunderstorms had poured more than 2 1/4 inches onto the official National Weather Service measuring station at the airport.

Almost an inch fell during a morning downpour. A nighttime storm delayed airport takeoffs for an hour or more.

The total far outstripped the daily rainfall record for the date, which was 1.42 inches.

The normal amount of rainfall at Dulles for the entire month of August is 3.78 inches.

Reports of heavy rain, as well as showers of hailstones, came from other parts of the Washington region as the storms that soaked the Dulles region moved on to the northeast.

But none of the official measuring stations recorded nearly as much as at Dulles.

At Reagan National Airport, rainfall was one-tenth of an inch.