Heavy rain is forecast at times Thursday afternoon through Saturday morning.
The Cascades and Olympics are forecast to receive six to eight inches generally with some eight to ten inch bull’s eyes around Mount Rainier, the Olympics and the Central Cascades. The lowlands are forecast to get one to two inches.
Rainfall this heavy would cause flooding on many area rivers. This includes any rivers flowing off the cascades from the Nooksack in the north to the Cowlitz in the south. Also any Olympic Peninsula rivers (especially the Skokomish) could flood if this rain occurs. Even the rivers of Southwest Washington such as the Chehalis and its tributaries could flood.
The Skokomish River is expected to reach the 16.5-foot flood stage in the afternoon Friday and is forecast to crest near 17.5 feet Saturday morning and hovering around that level through the weekend.
This forecast rainfall is still two to three days ahead. On Monday, models forecast the rain to mainly fall in British Columbia. On Tuesday, the models aimed the heaviest rain at Western Washington. New model runs could send the heavy rain in another direction. However, at the moment models are in rough agreement that some heavy rain will fall over western Washington.