Heavy Western Washington rain heightens risk of landslides
The Seattle region got a 16-hour break from the rain Sunday. It was the third-longest dry stretch this April, which is quickly rising to become one of the wettest on record.
As a result, the National Weather Service has issued winter storm warnings for the mountains, and warns that the risk of rain-induced landslides is much higher.
One mudslide shut down rail traffic between Seattle and Everett through at least Tuesday. Sound Transit also modified its regular bus schedule while “monitoring soil saturation and reviewing upcoming weather to determine when service will resume.”
The last time the region had this much rain was in 1993 — the month that Seattle Mariners Chris Bosio threw a no-hitter. The National Weather Service also noted a few events from that year.
The last time Seattle had an April comparable to this one in terms of rainfall, it was 1993. “Sleepless in Seattle” was 2 months away and Nirvana’s “In Utero” was released 5 months later. #wawx
— NWS Seattle (@NWSSeattle) April 16, 2018
Landslides and rain
The National Weather Service warns that rain has over-saturated the soil throughout the region.
Rainfall of up to 2 to 5 inches over the lowlands and foothills of Western Washington in the past several days has once again increased soil moisture to high levels. Light to moderate showers are expected today that could add up to only a half an inch to an inch in some places. But with these wet soils that could be enough to trigger a landslide or two. This elevated threat will persist through Tuesday, before slowly decreasing over the following few days.
Several landslides have already been reported or suspected in various locations in Western Washington in the last day or two, including on the Burke-Gilman Trail in King County, and this morning on the railroad tracks just south of Everett.
Western Washington rain
This April is officially the fourth wettest on record for the Seattle region. The previous record was set in 1894. The weather service says that other records could fall with more rainy days ahead. The rainiest April day in 22 years was Saturday, April 14, according to Patch. Seattle had 1.63 inches of rain; Tacoma had 1.1 inches; Kirkland measured 1.20 inches; Edmonds saw 1.01 inches, and North Bend has 1.25 inches of rain.
The National Weather Service expects that the region will get a couple dry, even sunny days Thursday and Friday.
It seems La Nina is measuring up to the cold, wet weather it is known for. And part of that measurement is rain. As of Monday April 16, it has rained 69 straight days in Seattle — 13 more days than normal.
Before La Nina struck in 2018 and in 2017, Western Washington was breaking hot weather records set more than 100 years ago. But La Nina this year and last year has brought nothing but rain. There were more than 139 days of rain by April 2017 (since the “water year” started in October).