Fall's 1st Storm Is On The Way: Puget Sound Forecast

SEATTLE — It may be a few weeks late, but the first taste of fall is finally on the horizon for the Seattle area. In stark contrast to last weekend, forecasters expect the next will host the first storm of the season, bringing much-needed rain and clearing out the smoke as temperatures dip below 60 degrees.

Seattle has recorded less than a half-inch of rain in more than 100 days, and the latest forecasts predict the incoming storm system will easily best that total between Friday morning and Sunday night, with well over an inch due in the Cascade foothills.

The welcome shift to seasonal weather follows a historic weekend in Puget Sound, where afternoon temperatures hit 88 degrees Sunday at the Seattle-Tacoma International Airport, making for the second-hottest October day in 130 years of records and the warmest ever recorded this late in the season.

Puget Sound also logged its warmest first half to October, with highs averaging almost 73 degrees — more than 9 degrees above normal.

Highs were already down double digits Monday and should keep to the upper 60s for most of the workweek. The National Weather Service expects temperatures will tumble into the 50s Friday and through the weekend.

Rain should pick up by Friday night and could dump an inch around Everett through Sunday, with Seattle picking up close to three-quarters of an inch. North Bend and foothill communities could see more than double.

In typical fashion for a fall storm, forecasters expect wind may present an issue in some areas, particularly with so many leaves lingering on area trees.

“Models are trending towards a wetter and stronger solution for this system,” said Dana Felton, senior meteorologist at NWS Seattle, in a forecast Monday. “Between little moisture for the last few months and leaves still on the trees, the breezy and possibly windy conditions for some of the area Friday could cause some impacts. Post-frontal convergence zone possible over Snohomish and King County behind the front Friday night into Saturday with the convergence zone extending into the Central Cascades.”

As cooler air moves in behind the front, forecasters expect the snow level will drop to around 4,000 feet, which may bring the first couple inches of snow to the higher elevations of the mountain passes.

Unfortunately, smoke from multiple fires burning in the region looks likely to stick around until the late-week pattern change, and an air quality alert has been extended through Thursday afternoon. The Puget Sound Clean Air Agency expects air quality will worsen Tuesday before returning to the moderate range mid-week.