By Martin Weil
Washington Post Staff Writer
Sunday, October 21, 2007

W elcome as it was, Friday's rain did little to end the protracted dry spell that has been afflicting much of the Washington region. Weather specialists said last night that much more will be needed.

By the time the storms had ended, a total of .37 of an inch of rain had fallen at Reagan National Airport, with most of it coming late at night. Some places got more, some less. However, said Luis Rosa, a Weather Service forecaster, "we have to get a lot of these events in the next few months" to make up for the area's rainfall deficit.

Dry conditions are expected to persist into December, Rosa said.

Friday's rain "is not going to have too much effect on the drought," said Alan Reppert, a meteorologist with AccuWeather, a private forecasting service.

Overcoming the shortfall of the past few months is "going to take a significant storm," Reppert said.

The nighttime storms that swept swiftly across the region Friday brought thunder and lightning that knocked out power for a time to some equipment at the sewage treatment plant at Blue Plains, the D.C. Water and Sewer Authority said.

A spokeswoman for the authority said it was unlikely that the incident, which cut power between 9 and 11 p.m., caused a release of untreated wastewater into the Potomac River.

The rains ended a record-setting string of 34 consecutive days without measurable precipitation at National Airport. It was the longest such period since the National Weather Service began keeping records for Washington in 1871.

Reppert appeared reluctant to attach great significance to the termination of the rainless period. The rain, he said, wasn't something "that has never happened before."

In addition, he said, more rain could fall as early as Wednesday. But the rain that is expected does not appear to be the intense, drought-dispelling sort, he said.

In the meantime, Richmond began enforcing mandatory conservation measures Friday, and Stafford County urged residents to continue conserving, especially indoors.

"Every drop counts," said county administrator Steve Crosby.