Let's show you the forecast precipitation. Here is the 24-h total ending 5 PM Tuesday. Wet offshore and light to moderate rain over much of Washington.
And it is still wet for the 24 h ending 5 PM Thursday.
But even more impressive is the strong low pressure offshore (972 hPa), low pressure that will produce strong winds over the Pacific.
Here is the forecast sustained winds at 2 AM Tuesday. An area around that low has SUSTAINED WINDS over 50 knots!
This low will move slowly to the NE. Big low system, strong winds, and slow movement implies the generation of big waves. An NOAA's Wavewatch III ocean prediction system forecasts exactly that (see image), with 8-9 meter waves (25-30 ft) forecast offshore. Such low pressure, strong winds,and waves is bad for the warm "blob" off our coast.