The storm snarled air traffic in Seattle, Portland and Spokane causing numerous delays and cancelled flights, reports CBS News correspondent Stephan Kaufman.
About 30 flights were scratched at Portland International Airport, a spokesman said, and Amtrak canceled service between Portland and Seattle.
A 41-year-old Seattle woman died Thursday after she became trapped in her basement while it flooded. Neighbors had called for help after they heard screaming.
A 28-year-old man was killed while he slept when the top of a tree snapped off and crashed into his home in a trailer park in McCleary, 18 miles west of Olympia.
Also in Washington, two people died in traffic accidents involving windblown trees, reports .
The storm is also hampering , where three climbers have been missing since the weekend.
In Edmonds, north of Seattle, about 50 residents of an assisted living facility were evacuated after a tree crashed through the third floor, flooding the building, Snohomish County emergency management officials said. No injuries were reported, and residents were sent to other facilities.
In King County, which includes Seattle, drenching rain slowed commuters to a crawl. Colder temperatures moved in Friday as the storm passed and winds calmed, bringing heavy snow to lower elevations.
Some Puget Sound Energy customers won't have their lights back on for days, spokesman Roger Thompson said.
The Evergreen Point floating bridge, which links Seattle and its eastern suburbs, remained closed early Friday and numerous other highways were blocked because of high water or windblown trees. The Hood Canal floating bridge, which links Washington's Kitsap and Olympic peninsulas, and the Tacoma Narrows Bridge were reopened early Friday after being closed Thursday evening because of wind gusts up to 74 mph.
The Oregon Department of Transportation closed three major highways crossing the Cascade Range because of fallen trees or downed power lines, and winds gusted past 90 mph on the Oregon coast.
The National Weather Service said rainfall was expected to be as high as 8 inches on the coast and 5 inches in the Cascade Range, with snow at higher elevations.
Rain drenched Qwest Field in Seattle just before kickoff of the NFL game between the Seahawks and San Francisco 49ers. The rain left standing water on the field, and about 30 minutes before kickoff, a power surge briefly knocked out the large video screens at both ends of the stadium.
Seattle public schools were closed Friday, as were numerous smaller school systems and The Evergreen State College in Olympia.