Increase Risk of Landslides This Week Across Washington
Heavy rain has prompted the National Weather Service in Seattle, Washington to issue a special weather statement, warning of increased landslide risk across the region throughout the week.
Rainfall of 4 to 5 inches last week has increased soil moisture to high levels across Western Washington. Heavy rainfall of 1 to 2 inches in the lowlands and upwards of 7 inches in the mountains of Western Washington is expected through Thursday. This amount of rain will put extra pressure on soil instability, leading to an increased threat of landslides.
West Seattle has already seen a mudslide that triggered a power outage and blocked Highland Park Way Southwest near Southwest Holden Street around 5 a.m. Wednesday morning. Commuters were rerouted around the hillside. Last Friday, landslides in south Seattle and Puyallup also closed roadways.
Additional rainfall expected through Thursday evening will pose a flooding threat. Another 2 to locally 4 inches are possible in the mountains through Thursday morning. The amount of runoff generated from this storm will be sufficient to put rivers flowing off of the northern Cascades at risk of flooding, including the Nooksack River.
Seattle will now enter the top 10 wettest February’s on record today, with 13 days still remaining in the month.