The pop and clink of New Year's Eve revelry gave way to a gray holiday drenching yesterday, as steady rain pelted the Washington region.

A flash flood watch -- indicating the possibility of flooding -- was in effect until midnight in much of the area, including the District of Columbia; Montgomery, Prince George's, Howard and Anne Arundel counties in Maryland; and Fairfax and Prince William counties in Virginia.

"The ground is saturated with heavy rain, and so it will have a hard time soaking in," said Scot Homan, a meteorologist with the Accu-Weather forecasting service.

Flood warnings -- meaning that flooding was occurring -- were issued late in the afternoon for Virginia counties including Loudoun, Fauquier and Rappahannock, Homan said. No serious damage was reported, however, and by about 10 p.m. the rain had headed toward Pennsylvania and New Jersey.

The downpour, which began about 2 a.m. and continued into the evening, wasn't bad news for everyone. Meteorologists noted that the rain was added insurance that the water shortage caused by last year's drought was over.

"It's a good thing we keep seeing storm after storm," Homan said. He said that more rain is possible today and tomorrow and that it could mix with snow in the northern and western suburbs.

"You want to get as much precipitation as you can in the winter months, so you can make up for the lack of precipitation in the summertime," Homan said. "You want to see a surplus in the winter months."

By late last night, 1.73 inches of rain had fallen at Dulles International Airport. The tally at Reagan National Airport was 1.51 inches.

Since early October, the Washington area has been doused with about 1 1/2 times the normal amount of rain and snow. The precipitation has filled the two Potomac River reservoirs, which had plunged to historic lows. The Baltimore reservoir system's supply is less plentiful but has not experienced drought problems.

The storms have allowed officials to relax or lift restrictions imposed last spring on such activities as watering lawns and washing cars.

Thanks to the recent wet weather, total precipitation in 2002 topped 34 inches at Reagan National Airport, about five inches less than normal, and 39 inches at Baltimore-Washington International Airport, 2.6 inches less than a typical year.

Although some public officials and homeowners welcomed yesterday's rain, it did cause some transportation problems, making roads slick and causing minor flooding on a few streets.

"There have been a lot of single-vehicle accidents, with [cars] running off the road, hitting the guardrail," said Dana Anthony, a dispatcher for the Virginia State Police. In one case, a car on the inner loop of the Capital Beltway overturned near Georgetown Pike.

No serious injuries were reported in the accidents.

Rain was not the only problem on the roads, according to the Maryland State Police office in Forestville.

"Believe it or not, today is more calm. Last night was hell," said a state trooper who declined to give her full name. She reported three overturned vehicles in Prince George's, two of them before the rain even started.

"This was just poor judgment. People need to take their time, slow it down," she said.

Police said that traffic was light yesterday.

That, too, was the observation of taxi drivers, for whom business normally increases on rainy days.

"The customers are not going out," said Christine Jackson, a customer service agent at Barwood Taxi in Montgomery County.

"The volume is not nearly what we normally have," said Al Powell, a dispatcher at Diamond Cab in the District. "I think people are sobering up from last night."

Staff writer Jamie Stockwell contributed to this report.