The Chehalis River fills its banks in November 2015as Sue Jarrad, a worker with the Washington State Department of Transportation, scrapes off debris from the state Route 6 bridge in Chehalis. Heavy rain is expected in the area. 
Pete Caster / pcaster@chronline.com

Series of Storms Set to Soak Western Washington

By Jordan Nailon / jnailon@chronline.com

The Pacific Northwest has a wet reputation to live up to, and Mother Nature is tired of waiting around. 

After a long spat of relatively dry weather, those old familiar seasonal storms are forecast to begin Tuesday morning and are not expected to stop until after the creeks have begun to rise.

That swampy outlook was provided by the National Weather Service on Monday morning during a severe weather advisory briefing. Jay Albrecht, lead forecaster with the National Weather Service, said that Tuesday and early Wednesday the weather will likely consist of little more than “garden variety” rainstorms. However, the precipitation is expected to increase as the week goes along, and moderately windy conditions are predicted to complicate matters by backing up storm drains with leaves and branches stripped from fragile trees.

Those storms, which are headed east from the Pacific Ocean, will be warm systems that should raise the snow line well above 5,000 feet and mean more rain in the mountains.

However, some snow is expected to accumulate on the North Cascades Highway. Winds are expected to push ocean swells up to 20 feet at times, resulting in beach erosion and dangerous conditions on the shore. The National Weather Services says that the multi-headed storm will deliver quantities of rain not seen in Western Washington since last spring, with upwards of 10 inches expected this week in some mountain areas.

A little more than three-quarters of an inch of rain is expected to fall between 11 a.m. Tuesday and 11 a.m. on Wednesday in Chehalis while the Olympia area is slated to receive upwards of 1.3 inches of rain in that span. Wind activity will likely pick up on Wednesday with gusts concentrated on the coast as well as sections of Puget Sound and the Kitsap Peninsula. 

“Autumn leaves will be blowing off the trees and collecting in some of the drains and we are expecting enough rainfall on Wednesday that we could get some urban flooding in flood prone low spots, areas that don’t drain that well. Especially in places where the leaves are clogging up the drains,” Albrecht said on Monday.

With the ground moistened and drains clogged by Wednesday night, meteorologists expect even more rain to arrive overnight Wednesday and into Thursday with between 6 and 9 inches of rain forecasted for the Olympic Peninsula and closer to 2 inches expected in the lowlands along the Interstate 5 corridor. Albrecht said the conditions will likely remain breezy throughout the week, with gusts up to 35 miles per hour in places, but he noted that there is not an official wind advisory in place.

“They will be strong enough to prune the trees from dead branches,” said Albrecht, who anticipates spot power outages beginning as early as Tuesday night and becoming more likely on Wednesday.

Albrecht noted that there is a possibility for moderate flooding on rivers in Western Washington later in the week. However, he pointed out that so far the Skokomish River is currently the only river predicted to make a real run at breaching its banks. On Monday, Albrecht said that the third wave of the storm, anticipated to arrive sometime Friday and then likely stick around for at least part of the weekend, was too far out to accurately predict its severity and the associated likelihood of increased flooding.