NWS is either going to be really right, or REALLY wrong. Below is their forecast for Paine Field.
Tonight
Rain. Steady temperature around 38. South southeast wind 13 to 17 mph, with gusts as high as 23 mph. Chance of precipitation is 100%. New precipitation amounts between a half and three quarters of an inch possible.
Monday
Rain and snow showers, becoming all rain after 1pm. High near 39. South wind around 11 mph. Chance of precipitation is 90%. Little or no snow accumulation expected.