As if on cue, Washington area residents pulled open their drapes yesterday to find a Christmas surprise: a brief but heavy morning snowfall that offered a rare storybook backdrop for the winter holiday.

Though forecasters had promised a dank day of sputtering rain, a nighttime mix of sleet and rain became heavy flakes by morning, turning the entire region gleefully white for just the second Christmas in 30 years.

The storm was much more severe in the Northeast, where airports and roads were closed last night, and as of 10 p.m., 18 inches of snow had fallen in Albany, 11 in parts of New York's Westchester County and 10 at places in Connecticut and Massachusetts. Still more was expected by sunrise.

By late last night, more than two dozen planes headed for New York or New England had been diverted to Dulles International Airport.

In the Washington area, slushy asphalt caused scattered accidents and briefly closed runways at Baltimore-Washington International Airport during the day. After dark, winds that gusted up to 40 mph tore down power lines, leaving thousands without electricity for a time.

But the storm arrived here on what may have been the ideal day for snow, given that schools and businesses were closed, traffic was negligible and most travelers were at their destinations. That left time for the snow to be savored.

Morning churchgoers in the District emerged from holiday services with eyes skyward as weighty, wet flakes swirled thick to the ground. Len Scensny, 51, of Takoma Park paused in front of St. Matthew's Cathedral to soak in the moment. "This is decorative snow," he said. "The kind you can see in the air but [won't] stick and cause problems. It's sky tinsel."

At least in Washington, the flake-filled skies and sled-tracked slopes were unanticipated by many people who had followed the forecasts, which this week had foretold another gray Washington Christmas with little or no snow. Nature, it seems, can still outwit the satellites, supercomputers and high-tech Doppler radar promoted breathlessly on television, said Barbara Watson, a National Weather Service meteorologist.

"It's just the state of the science," she said. "These are complex storms that are coming up the coast. Just a couple degrees of difference can mean the difference between rain and snow."

The snowstorm, which began earlier this week in the nation's midsection, was barreling up the East Coast late yesterday after it dumped up to 15 inches on Kansas and claimed the lives of at least 14 people in several states, most in traffic fatalities. Fast-falling snow closed more than 100 miles of the New York State Thruway. Some parts of Pennsylvania got more than 20 inches of snow, and roads were closed there, too.

Here, it left more than 3 1/2 inches in such places as Reston and upper Montgomery County and more than two inches closer to the District. The last time it snowed more than an inch on Christmas was 1969, when Washington was socked with more than four inches.

Yesterday's accumulation created enough slush to prompt managers at the Virginia Department of Transportation to summon plow and salt truck operators throughout the morning.

About 200 trucks were on the roads in Northern Virginia by 1 p.m., VDOT spokeswoman Jennifer Finstein said. Crews were expected to continue salting and sanding the roads through last night because VDOT managers were concerned about icing, she said.

In Maryland and the District, officials said they sped up their planned deployment of snowplows yesterday when the storm exceeded predictions. But by evening, with the skies clearer, temperatures still above freezing and plows expected to work through the night, authorities expressed confidence that roads would be navigable by this morning.

"Before rush hour, every street in the county will have been treated" -- either plowed, fully sanded, or sanded on hills and at intersections, said Tom Orr, chief of field operations for the Montgomery County Department of Public Works and Transportation. The rural parts of the county received up to four inches of snow.

Just before midnight, the temperature was five degrees above freezing at Reagan National Airport and three degrees above at Dulles, but Orr warned that the region's temperatures were expected to drop overnight, and he said rush-hour commuters should use caution.

Yesterday's conditions resulted in scattered fender benders and single-car accidents, but no serious crashes were reported. The worst trouble locally was in Montgomery and Loudoun counties.

"People go off into ditches, into creeks," said Nick Altom, a dispatcher for the Loudoun County Sheriff's Department. "We're telling people to stay home."

For most of the region, that was the agenda. In Bethesda, Chris Meyers, 35, seized the moment to fashion a new use for the undersized canvas hat his mother-in-law had given him. As his 2-year-old daughter Abigail looked on, he made it the crowning prop for a four-foot snowman.

On the slopes of a rolling hill at Wolf Trap Farm Park in Vienna, bundled children pelted each other with snowballs and hopped on their sleds, calling the white ground a joyous surprise.

"All I heard was it was supposed to rain," said Jan Kraft, 22, strapping on a snowboard. Just enough snow for the board, said her 16-year-old brother, David. "You don't need much," he said. "But a little more might make the landings softer."

The snow had Jody Patrick, 42, thinking of her childhood in Upstate New York with its heavy snows.

Patrick snapped a photo of her 8-year-old daughter, Shea, lying prone in the snow in her blue snow jacket.

Washington's Christmas, of course, was not all about play.

Christmas services took on more solemn tones at Washington National Cathedral, where trouble in far-off places figured into the sermon.

The Rev. Nathan Baxter, dean of the National Cathedral, called on the faithful to remember those in the military far from home. He said regardless of any political or theological position, what matters most is that those serving their country "know they are loved."

Volunteer work, another staple of the holiday, was on the mind of 12-year-old Lisa Prussick, who said that on any other day, she might be out playing in the snow.

She was one of approximately 1,100 volunteers from the D.C. Jewish Community Center who fanned out across the city to provide for the needy. Lisa and her family delivered meals to homebound senior citizens.

"This made me feel good, like I did a good deed," she said.

Navy Capt. Charlotte Wise is Christian but worked with the community center's volunteers, organizing drivers at the center to deliver more than 400 meals. Wise said she tries to spend Christmas Eve with her family but volunteers every year on Christmas morning.

"This is the way we celebrate Christmas," she said. "This way, we are living out our faith."

By day's end, air travel, especially from and to the Northeast and North Central states such as Ohio and Michigan, was facing serious interruptions because of snow and ice.

At Dulles Airport, where at least 27 planes had arrived after being diverted from snowed-in airports to the north, according to Tara Hamilton, a spokeswoman for the Metropolitan Washington Airports Authority, domestic passengers were taken off some flights, and many were seeking overnight accommodations in this area.

Locally, nearly every flight from the region's three major airports was delayed throughout the afternoon and into last night.

BWI was most significantly affected. Airport officials closed both runways for about two hours, beginning the shutdown at 11:30 a.m. One runway was reopened at 1:30 p.m. and the other at 2:55 p.m. The shutdown allowed crews to clear the tarmac of slush, spokeswoman Cheryl Carley said. About 12 flights were delayed and seven canceled.

The only bright spot was that air traffic was lighter than normal because of the holiday, so fewer travelers were affected, Carley said. On a typical day, 55,808 passengers use the airport; yesterday, about 36,000 were expected. The runways at Reagan National and Dulles International airports remained open all day, but travelers still experienced delays.

Winds strengthened as the day wore on, and by 10 p.m., 40 mph gusts were being reported at Camp Springs and other spots across the area.

A tree fell onto an automobile on Embassy Row last night, but the car's two occupants were reported uninjured. The tree toppled in the 2500 block of Massachusetts Avenue NW about 10:15 p.m., a witness said.

At one point as many as 11,000 homes lost power in parts of Northern Virginia, according to a spokesman for Dominion Power. Ice and wind tore down trees and branches, and in one or two cases, cars sliding off roads knocked down power poles, he said. The Springfield and Annandale areas were most severely affected, he said. By late last night, the number of those without electricity had been cut to less than 2,000, he said.

A spokesman for Potomac Electric Power Co. said late last night that more than 4,400 people were without electricity, most of them around Harrison Street NW in the District and many others in Montgomery County.

The National Weather Service predicted that high temperatures here would be in the 40s through next Wednesday, with cloudy conditions but a low probability of more precipitation.

Staff writers Michael Amon, Justin Blum, Lyndsey Layton, Allan Lengel, Martin Weil and Debbi Wilgoren and the Associated Press contributed to this report.

Paul Anderson takes a Christmas Day walk through the unexpected snowfall along Holborn Avenue in Annandale. It was the region's first white Christmas in decades.Eight-year-old Brendan Bloom runs past pines in Howard County's Highland area. The storm strengthened last night as it moved to the Northeast, with as much as 18 inches of snow reported in Albany and 10 in Connecticut and Massachusetts.The new-fallen snow in Ednor Park in Montgomery County leaves evidence that people weren't the only creatures out in the unexpected snowfall.