The National Weather Service says heavy rain Tuesday through Wednesday could drive some Western Washington rivers above flood stage. Rainfall totals of 5 to 8 inches are possible in the Olympic Mountains during that 48 hour period, with 4 to 7 inches possible in the Cascades. The snow level will rise to 7000 to 8000 feet through Tuesday night, then fall to around 6000 feet late Wednesday as precipitation begins to decrease.
These rainfall amounts — if they occur — could result in some flooding on the more flood-prone rivers flowing out of the Olympics and Cascades, and the Chehalis in southwest Washington. Western Washington rivers are running low currently, but the rain will cause them to rise quickly and flooding could possibly begin later Tuesday or Wednesday.
One of the most flood-prone rivers is the Skokomish which is expected to rise to the 17-foot flood stage midday Tuesday and reach 17.5 feet in the late afternoon.