Let me show you the latest UW WRF model forecasts, starting with the 24h totals ending 5 AM Saturday. Looking at the regional totals, we see that western WA and southern BC get doused, as does NW Oregon. Dry over the Columbia Basin and eastern Oregon.
A closer in view suggests that the north Cascades and southern BC will be hit hard, with some locations getting 1-2 inches. Puget Sound will be moistened by perhaps 1/3 inch. Your plants will be happier.
You will notice that the ensemble mean indicates about .3 inches in total over Seattle, but there is considerable spread, and thus uncertainty, in the forecasts, with totals ranging from .05 to 1.2 inches.
The Cougar Creek fire near Mt. Adams was quite active today, producing huge amounts of smoke, something obvious on the visible satellite photo below.
The amount of smoke was so large that the local weather radars picked up the plume. An example is shown below from the National Weather Service Portland radar. Very impressive fire.