SEATTLE — Heavy rainfall on the back of week-long storms increased the risk of landslides in Western Washington later this week, the National Weather Service announced.
The weather service said rainfall over the past three days has increased soil moisture levels across the Western Washington lowlands. Another 1 to 3 inches is expected Wednesday through Thursday, putting the land at increased instability, officials said.
“Cumulative rainfall over the last week has soaked soils to the point where the Washington landslide risk is at elevated levels,” the National Weather Service said in a special weather statement sent out at 11:37 a.m. Monday. “Landslides have already been reported in various locations in Western Washington…including near North Bend. More landslides are possible across Western Washington.”
Landslides become more likely during bursts of intense rainfall or over periods when heavy rain has saturated the ground. Large-scale slides were last seen on Whidbey Island, forcing the evacuation of 34 homes in last March.
Slides have long been known to hit Seattle, as more than 1,340 landslides occurred in the city since 1890. Slides are most often seen in late winter or early spring as the ground becomes saturated following a long winter of rain.
For up to date information on landslides, as well as how to report additional slides, visit the weather service’s Seattle page here. The Washington State Department of Ecology also has a Puget Sound Landslides map which tries to estimate slope stability.