Strong winds brought November's chill to the Washington region yesterday, knocking down a few power lines in the process.

The winds were strongest before dawn, whirling leaves in Northwest Washington, toppling tree branches in Rockville and banging the rigging on sailboats in Annapolis Harbor. Thousands were left without power in Herndon and McLean, at least briefly, and three schools in Anne Arundel County were shut for the day.

At the same time, temperatures fell into the high 40s -- beginning an erratic stretch of weather that may last into next week, forecasters said.

"We're going into a little bit of a roller-coaster ride as far as temperatures go over the next seven-day period," said Paul Pastelok, of the AccuWeather forecasting service.

Pastelok said temperatures may climb back into the 60s today, and then drop again, with lows possibly in the 30s as a cold front arrives next week.

Yesterday, Pastelok said, the high winds were caused by the departure of a rainy cold front that passed through the area Thursday.

In its wake, he said, high winds from the atmosphere descended, so that fast-moving air that should have been buffeting helicopters was instead prowling along the ground.

The highest winds were recorded before dawn: 45 mph at Reagan National Airport, 40 at Dulles International, 37 at Baltimore-Washington International.

The gusts toppled power lines in Annapolis, leaving streetlights out and forcing the State House to use backup generator power. Broadneck High School and two elementary schools in Anne Arundel were closed because their power was out.

Elsewhere in Maryland, about 1,100 customers of Pepco and about 34,000 customers of Baltimore Gas and Electric were without power at some point.

Early yesterday afternoon, some electrical wires were knocked down in Ashton, causing a small brush fire that emergency workers quickly put out, said Pete Piringer, a spokesman for Montgomery County's Fire and Rescue Service. "Other than that," he said, "it's been very manageable."

In Virginia, 15,000 customers lost power at some point because of the winds, according to a spokeswoman for Dominion Virginia Power. As of noon, 653 customers were still without power, with most concentrated in Herndon and surrounding areas such as Tysons Corner and McLean.

The problem was caused by a large tree that fell on a power line on Old Dominion Drive, just north of Bellview Road in McLean, snapping the cross arms of several poles, the spokeswoman said.

The winds, mainly out of the west and northwest, forced a small-craft warning on the Chesapeake Bay and a warning to drivers on the Chesapeake Bay Bridge. They also flattened waves on the Delaware coast, leaving surfers in short supply, according to surf shops.

In Annapolis, Brian Guptil of Seattle had parked his 44-foot sailboat at City Dock and said he intended to stay.

"You're down to the point of not sailing" in this weather, he said. He said his boat's wind gauge hit 40 miles an hour in the early morning.

But a companion, Alicia Alexander, said she saw a good side to the wind: At dawn she was near the marinas of Annapolis' Eastport neighborhood and listened to the sailboats' gear clang, whistle and hum.

"That wind made beautiful music in the riggings," Alexander said.

Staff writers Lila Arzua and Rebecca Dana contributed to this report.