The National Weather Service in Seattle has issued a Special Weather Statement regarding an increased risk of landslides in the area.
Heavy rainfall Wednesday through Thursday will lead to increase risk of landslides in Western Washington. Local crews have already experienced one landslide this week near Vesta.
Rainfall of 1 to 3 inches over the past couple days has increased soil moisture to high levels across the lowlands. 1 to 3 inches of additional heavy rain of is expected Wednesday through Thursday. This will put extra pressure on soil instability, leading to an increased risk of landslides. Cumulative rainfall over the last week has soaked soils to the point where the Washington landslide risk is at elevated levels.
Areas most susceptible to landslides under these conditions are steep coastal bluffs and other steep hillsides.
Another concern is the risk of flooding on local rivers. Heavy rain possible Wednesday and Thursday could lead to flooding on a few rivers beginning Thursday.
Because there is uncertainty in where the heaviest rain will fall, it is difficult to say which rivers may flood. At this time the Chehalis is most risk of flooding.