Already the region has seen anywhere between 1-3 inches of rain through midday Monday, and another storm due in for Wednesday and Thursday is expected to drop an additional 1 to 3 inches of rain.
Cumulative rainfall over the last week has soaked soils to the point where the region's landslide risk is at elevated levels, NWS forecasters said, and that amount of rain will put extra pressure on soil instability, leading to an increased risk of landslides going forward.
Already a few landslides have been reported around the area, including North Bend, and more landslides are possible this week, especially near steep coastal bluffs or steep hillsides.
The risk is not expected to let up any time soon. After the rather wet storm Wednesday and Thursday, long range models suggest another fairly wet storm to push through the region late Friday into Saturday.
River flooding possible too
In addition to increasing landslide risk, the soggy storm midweek is also bring a chance of river flooding. Right now, forecast models haven't zeroed on in which section of the mountains will get the bulk of the rainfall, but the Skokomish, Snoqualmie and Chehalis Rivers have the greatest chance of experiencing some flooding.
For More Information:
National Weather Service Landslide Index for Seattle