How's this for wet: Washington, D.C., got as much rain over the last two days as soggy Seattle usually receives in all of May.

Or this: the American Automobile Association's regional emergency line rang with 120 calls an hour yesterday from stuck motorists, 50 percent above normal.

Or this: the Potomac River is rising by a major amount for the first time this year and is expected to reach flood level or close to it in Western Maryland and West Virginia within two days.

It's been raining so much this month that even the weatherman, who makes his living from such things, is getting bored.

"I hope it quits for a little while," said National Weather Service forecaster Jim Schulz. "I'm going to have to change my yard from a hayfield into a rice paddy."

Yesterday's downpour drenched the morning rush hour, knocked out power to several thousand houses in Glen Echo and Springfield and at least two schools, forced officials to close low-lying roads, and added enough precipitation to the year-to-date total to increase it above average.

A slow-moving low pressure system blanketed the eastern Ohio Valley yesterday before moving on to the Mid-Atlantic states and Northeast. It may have caused a tornado that came ashore yesterday morning on the Outer Banks of North Carolina, south of Buxton, flinging a camper and his tent into a creek, officials said. The Pennsylvania man was hospitalized with undetermined injuries.

Improvement in the weather is forecast for the Washington area today -- sunny with temperatures in the seventies -- but rain may return by the weekend.

The region received up to 1 1/2 inches of rain between Sunday afternoon and yesterday afternoon, which is what Seattle usually gets for the entire month of May, admittedly one of its drier months. That brings the regional year-to-date rainfall total to 16.2 inches, compared with the usual 14.92 inches, according to Accu-Weather.

Still, the month's total of 5.3 inches of rain at National Airport totaled by Accu-Weather is less than last year's 7.77 inches and far lower than the record of 10.69 inches measured in 1953. And the 11 days on which it has rained here so far this month is exactly average for May.

The Potomac is expected to crest at Little Falls, north of the city, tomorrow afternoon but will be a foot or two short of flood level, said Weather Service hydrologist Richard Hitchens. The river is expected to rise to half a foot above flood level by this evening at Shepardstown, W.Va., and will crest at just below flood level Thursday morning at Point of Rocks, Md.

The Maryland Department of Natural Resources issued a safety warning yesterday for boaters on the Potomac, which has risen so high that new safety markers have been washed away or submerged.

"The Potomac is currently at a dangerously high level and continues to rise," Sgt. Morris Jones, of the Natural Resources Police, said. "Strong currents and submerged obstructions pose additional hazards for boaters" from the District to Western Maryland.

Low-lying roads turned into waterways yesterday. Traffic was blocked for nearly five hours on MacArthur Boulevard between Goldsboro Road and Cabin John Parkway in Glen Echo while Potomac Electric Power Co. crews repaired power lines damaged by fallen trees and heavy rains, Montgomery County police said. About 1,500 houses nearby lost power temporarily, Pepco spokesman Steve Arabia said.

Woodburn Road in Annandale near Fairfax Hospital was closed for five hours yesterday and water was pumped off Backlick Road in Springfield after it flooded, stalling several cars. A short stretch of Columbia Road in Columbia was closed in Howard County, and several gravel back roads were shut in Loudoun County, officials said.

The rain also temporarily closed U.S. Route 50 near the Kent Narrows Bridge on the Eastern Shore and a section of the Harbor Tunnel in Baltimore.

One result of the rainy spell will be a delay in road construction, according to Mary Anne Reynolds, of the Virginia Department of Transportation. "The ground is so thoroughly soaked now it may take four or five days to dry out so we can resume work," she said.

Virginia Power said a lightning arrestor broke, possibly because of the storm, and knocked out electricity for 20 minutes to 2,900 customers in Springfield, including Hayfield High and Elementary schools.

Staff writers Veronica T. Jennings and Claudia Levy contributed to this report.