With coming rain, concern turns to flooding, flat roofs

Western Washington residents welcoming the arrival of today's snow-melting rains now must turn their attention to a new problem: where all this white stuff will go as it melts.

The Weather Service today warned that structures with flat roofs face a heightened risk of collapsing as rain soaks the heavy snowpack sitting on them.

"We've already had a few roofs collapse justs from the snow," said Ted Buehner of the National Weather Service, adding that homeowners and business with flat roofs should consider removing the snow before it is saturated with rain.

In addition, large pools of water in streets and parking lots could lead to localized flooding around the metro area because many storm drains have been choked with snow, ice and debris. Residents are also advised to check the storm drains near their homes and clear them if possible.

By late morning, snowfall had give way to rain in much of Western Washington, including the Seattle area, although snow was still falling on higher hills. The temperature at Seattle-Tacoma Airport at 10:30 a.m. was 34 degrees, and was expected to rise to 36 this afternoon.

A snow-laden evergreen fell across the northbound lanes of Aurora Avenue this morning near 60th Street, Rick Sheridan from Seattle Department of Transportation said. One northbound lane is open while crews work to remove the tree.

A mix of rain and snow was forecast in the Puget Sound area tonight and Christmas Day, with high temperatures gradually rising into the 40s this weekend.

Warmer temperatures will reveal where water pipes have burst during the subfreezing conditions. "I have a feeling plumbers are going to be pretty busy over the next week," Buehner said.

He stressed that the snowmelt hazard is not expected to be as severe as in December 1996, when torrential rains fell on top of two feet of snow in the Puget Sound area, taking down carports, awnings, boats and entire sections of buildings.

The hardest-hit area then was the Edmonds marina, where 14 covered mooring sections collapsed, sinking 100 boats, damaging 300 more and causing $24 million in damage. The marina has since been rebuilt with a roof designed to let snow slide off.

Earlier this week, the heavy snowfall was blamed for a roof collapse and gas leak at a mobile-home manufacturing business in Marysville. No one was injured.

Buehner said this week's warm-up will be gradual, and the forecast rains are light, so the flooding threat isn't as severe as if all the snow were to all melt at once.

Meanwhile, mountain passes are expected to get 12 to 18 more inches of snow by the middle of Christmas Day, the Weather Service says.

This morning's fresh coating of snow actually improved traction for some Metro Transit buses, said spokeswoman Linda Thielke. But about half of routes, particularly hilly ones like those that transit east-west across Capitol Hill, remain shut down.

"It's disappointing to people not to have all the buses running, and we're frustrated too," Thielke said.

There have been no major bus accidents or serious injuries, which Thielke attributes to Metro's "conservative" approach.

Buses that are running have been jampacked. But ridership is expected to drop sharply — as it always does — on Christmas Day.

Among Wednesday morning's trouble spots were Northgate, Maple Leaf and other northeast Seattle neighborhoods, where a sudden freeze around 6:15 a.m. left the streets icy. About 38 buses were reported stuck at 10 a.m., though many were quickly pulled free.

Mechanics, dispatchers and customer service representatives have been working 12-hour shift for the past week, Thielke said. With a holiday schedule Thursday, and a "partial holiday" schedule for most of next week, the slowdown will be welcome.

"We hope that will give us the recovery time we need to get the buses in the shop to get repairs and get checked out," she said.

The agency advised people to go to its Web site (http://transit.metrokc.gov/) and click on "adverse weather" to check what routes are running.