The remnants of Hurricane Ivan spawned an unusually high number of tornadoes that hopscotched from southern Virginia to northern Maryland with destructive winds estimated in one case at 200 mph, weather experts said yesterday.

Witnesses reported funnel clouds that roared along busy highways and country fields, ripping out trees, shearing off rooftops and demolishing barns and other buildings. An elderly woman and her daughter were killed early yesterday in the town of Colora, in Cecil County, Md., when a large oak fell onto their ranch house.

Fifteen homes were destroyed in Virginia, said Dawn Eischen, spokeswoman for the state's Department of Emergency Management. She said destruction ranged from downed trees and power lines to $95 million in damage to an industrial park near Roanoke.

Five people in Virginia suffered minor injuries, one in Fairfax County, two in Fauquier County and two in Frederick County, Eischen said. More than 100 houses and businesses and two public buildings reported major damage. An additional 1,921 homes and 27 businesses reported minor damage. She said much of the damage was in Northern Virginia.

On Friday, Gov. Mark R. Warner (D) declared a state of emergency. Virginia officials said the storm spawned 30 tornadoes in their state alone, far exceeding the number Virginia usually records in a year. In 2002, the most recent year for which figures are available, Virginia recorded seven tornadoes and Maryland had 14, according to the National Climatic Data Center.

Teams from the National Weather Service said it will take several days to investigate about 40 tornado reports received between Friday and yesterday morning. They visited smashed houses and battered yards, trying to determine the velocity and direction of the wind, looking for clues in the stubble of crops and patterns of twisted trees that would confirm that a tornado caused the destruction. Spokesman Kent Laborde said investigators found evidence in the first hours that a tornado with winds of 158 to 206 mph formed in Fauquier County.

Meteorologists at the National Weather Service's regional office in Sterling knew by midday Friday that trouble loomed. Although Ivan had been downgraded to a tropical depression by the time it approached Virginia on its northbound trip from the Caribbean, the storm was wide and powerful. Virginia and Western Maryland were on the east side of its track, the area where tornadoes were most likely to form, said Andy Woodcock, a senior meteorologist at the Weather Service.

"It was just a phenomenal storm, in terms of energy," he said. "And we were on the east side of the low pressure center. . . . We knew things were going to go pretty crazy."

As forecasters peered at satellite images and looked at the data from surface weather stations and balloons, Woodcock got on the phone and told the Smithsonian Institution to shut down a celebration of the American Indian on the Mall and told Merriweather Post Pavilion to cancel an outdoor concert and evacuate the 15,000 attending.

By 6 p.m., all the weather scientists needed to know was outside their window. Three-quarters of a mile to the south, they spotted a black funnel cloud above the tree line near Dulles International Airport. Woodcock called the control tower and told air traffic controllers to evacuate.

Moments later, the weather experts themselves sought shelter, transferring their duties to the Philadelphia office of the National Weather Service and taking refuge in the copier room, which has no windows and was built with reinforced concrete so it could double as a safe room during emergencies.

Nine meteorologists, a ham radio operator and a UPS deliveryman who happened to be dropping off a package huddled together, Woodcock said. They took a government phone book and an emergency procedure manual with them, he said.

When they emerged 10 minutes later, the tornado had passed. In 20 years as a meteorologist, it was the first time Woodcock had seen a tornado. "It was pretty cool," he said. "It was sinewy, undulating and moving northward pretty rapidly."

It also could be deadly. About 3:30 a.m. yesterday, a large oak fell onto a house in Cecil County, killing Grace M. Jackson, 87, and her daughter, Betty A. Kline, 62, of Colora School Road, who had been asleep in their beds. Kline's husband, Harry R. Kline, 64, told state troopers that he was in another part of the house and was unable to reach his wife and mother-in-law before the tree fell. He escaped by crawling out through the roof and was treated for minor injuries at the scene.

In Maryland, about 30 properties in Cecil County and 40 in Frederick County were damaged, officials said.

The destruction seemed arbitrary -- one house flattened while the houses around it were untouched. In Chantilly's Pleasant Valley neighborhood, only two of several hundred homes were seriously damaged: those owned by the Hepler family and a next-door neighbor.

James Hepler said it took less than a minute for a funnel cloud to destroy his home. The wind blew off a large section of the second floor, which ended up lying on his driveway and neighbor's yard. Videotapes, sofa cushions and photographs were found several blocks away.

"One minute we were lying there, and the next thing I knew there was daylight coming into my basement," Hepler told National Weather Service and county officials yesterday.

Motorists near Dumfries and Hoadley roads outside Manassas saw a funnel-shaped cloud about 5:30 p.m., said Capt. Tim Taylor of Prince William County's Fire and Rescue Department. It headed northeast, touching down as if it were skipping in the neighborhoods of Woodbine Woods, Bel Forest West, Lake Jackson and Westchester, he said. There were no injuries directly attributed to the tornado, but by yesterday afternoon there were several reports of chain-saw injuries and trees falling on people during the cleanup, Taylor said.

Prince William officials warned about price gouging by unscrupulous contractors and said consumers should check with their insurance companies before they agree to large repair bills.

Maj. Paul Mercer of the Fauquier County Sheriff's Office said two dozen houses in Remington were damaged Friday night, some severely. Residents were evacuated last night because of fears of electrical damage, he said.

Jeanne Heaney of Remington weathered the storm in her basement with her two children. "We could see the debris flying from our house," she said. Although her house was not damaged, she said, she saw the tornado up the road where her friend Tammy Hall lives.

Hall's family, including her six young children, escaped injury and spent the night at Heaney's house. "They were just basically devastated," Heaney said.

She added that, for this storm at least, the stark news reports were not exaggerated. "They always try to make it sound bad," she said. "This time it really was."

Because of heavy rains to the west that accompanied the storm, the Potomac River is expected to swell three feet above its flood stage at Point of Rocks sometime this afternoon, said Rich Hitchens, a hydrologist with the National Weather Service. Flooding is predicted to be mild, he said.

In western Pennsylvania, downtown Pittsburgh's Point State Park was underwater yesterday where the Monongahela and Allegheny rivers join to form the Ohio. Dozens of boats that had broken free of their moorings were floating down the fast-rushing rivers. Williamsport, Pa., collected 61/2 inches of rain in 24 hours, and Pittsburgh got a record 5.95 inches Friday.

The National Weather Service predicted that the Ohio River would crest today at 46 feet, about 10 feet above flood stage and close to its record. By early afternoon yesterday, it was at 41.7 feet.

Across West Virginia, flooding and mudslides had blocked 207 roads and damaged hundreds of houses, authorities said.

Convoys of electrical trucks, relief agency mobile feeding stations and military vehicles carrying National Guard troops in fatigues streamed through the battered Southeast all day yesterday as the immensity of Hurricane Ivan's destructive path came into sharper, grimmer focus.

Alabama Gov. Bob Riley told reporters that he was "absolutely shocked at the devastation." Even as parts of storm-rattled Alabama and Florida began to return to some semblance of normality, there were still 1.3 million people in 13 states without power.

Staff writers Tara Bahrampour, Carol Morello, David Cho, Manny Fernandez and Manuel Roig-Franzia and the Associated Press contributed to this report. Fernandez reported from Florida and Roig-Franzia from Alabama.

Ken Keasbey empties the contents of his grill on what's left of his deck as he and others of his Chantilly neighborhood clean up.Helen Aument looks at the nails still attached to a piece of her neighbor's fence that impaled her home in the Frederick County community of Adamstown. A mother and daughter died when a tree crushed their house in Colora, Md.Forecaster Andy Woodcock called it "a phenomenal storm."