The remnants of Hurricane Katrina reached the Washington region last night, having traveled far from the Gulf Coast but still possessing the strength to bring heavy rain, high winds and a possible tornado.

As the National Weather Service issued tornado warnings for several Virginia counties, winds ripped across the Marshall area of Fauquier County about 8:30 p.m., severely damaging at least three houses.

Trees went down in many spots, rain was heavy and lights went out in thousands of homes across Northern Virginia.

Authorities were not certain whether the damage centered on Cobbler Vista Lane in Fauquier was a result merely of high winds or of a tornado, said Capt. Darren Stevens of the county's fire and emergency services department.

But he said the houses most affected were "no longer habitable."

Hurricanes that come ashore far to the south and west of the Washington region often spawn tornadoes in this area, said Weather Service meteorologist Brian Guyer.

Formation of tornadoes, with their whirling funnel clouds, is fostered by the same atmospheric rotation that sends bands of rain spiraling around the eye of a hurricane.

Hurricanes also fill the atmosphere with moisture for hundreds of miles around, yielding the oppressive humidity that fuels storms such as were experienced in the region yesterday.

"We have seen this before," Guyer said.

In Albemarle County, a powerful thunderstorm tore down trees in the White Hall area. It ripped down more trees in Culpeper County before roaring into Fauquier.

Shirley Thorpe, at home in the Marshall area, was confident that what struck his neighborhood was a tornado.

He described "the way it sounded" and the damage it did, taking the siding off his daughter's home and the garage doors off a grandson's house. He also cited the downed trees. "It had to be something to take these trees up . . . by the roots," Thorpe said.

Anne Hudson, another resident of that neighborhood, said she, too, was struck by the sound the storm made. "It sounded like a train," she said.

The storm was weaker when it struck the Airmont area of Loudoun County, but the wind and rain "got really bad," said resident Teresa Duhring.

The lights went out on Ebenezer Church Road, and the rain was "torrential," she said.