The regional radar image at 2 PM was amazing and dramatic (see below). Moist flow from the west is approaching our coast, rising on the western side of the Olympics and sinking on its eastern side. The result is distinct hole in precipitation to the lee (east) of the Olympic barrier....a rainshadow. As the air rises again on the Cascades, precipitation reforms.
Why is the rainshadow over Seattle to Everett rather than over Sequim? Because of the westerly wind direction aloft rather the typical south-southwesterly flow of winter.
But what is really exceptional is the satellite imagery. Here is the image from the NASA MODIS satellite...you see the black, cloudless "hole" downstream of the Olympics. It is sunny there!
Here is a blow up of the "cloud shadow". Really dramatic.