Rain is expected to begin along the coast and Olympics by midday and gradually spread inland through the afternoon and evening.
Western Washington is set for its first significant autumn storm Friday, bringing widespread rain, gusty winds and the chance of isolated power outages before drier, cooler weather returns for the weekend.
KOMO News Meteorologist George Waldenberger said clouds and cool temperatures will linger Thursday, with highs mainly in the upper 50s.
Rain is expected to begin along the coast and Olympics by midday and gradually spread inland through the afternoon and evening.
A few showers could reach Kitsap County, Whidbey Island, the San Juan Islands and Bellingham during the afternoon, while Seattle, Tacoma and Everett may not see steadier rain until later.
By Thursday evening, rain is expected to become more widespread across Western Washington, including Seattle, and showers will continue overnight. Some heavier pockets of rain could develop Friday morning.
Friday will remain chilly and unsettled, with off-and-on rain and spotty thunderstorms. Waldenberger said most areas could receive between a half-inch and 1 inch of rain, with higher totals possible in the Olympics and Cascades.
Wind will be the larger concern, particularly along the coast and Strait of Juan de Fuca. Gusts of 30 to 50 mph are possible, with stronger gusts near Grays Harbor. Isolated power outages could occur.
Friday will be a KOMO Weather Warn Day because of the wind risk, Waldenberger said. Wind advisories could also be issued.
Showers are expected to linger over the Cascades through Friday night and into Saturday morning. Snow levels could fall to between 5,000 and 6,000 feet, potentially bringing the first dusting of snow to some Olympic and Cascade locations.
The rain could slow wildfire activity and reduce smoke, although larger fires may continue smoldering and could become more active again once conditions dry out.
Saturday and Sunday are expected to be drier, with chilly mornings and crisp afternoon sunshine. Fog could form in some lowland areas where skies clear, while the highest peaks may see frosty conditions.
