Does northwestern Washington state have any Katabatic winds?
I think it would be helpful to begin with a definition; a Katabatic wind is simply a wind blowing downslope, or down an incline of any sort. In western Washington, they're most frequent when high pressure is east of the Cascades and a low offshore or along the coast. Because air moves from high to low pressure, that generates easterly winds (or northeasterly at times) which move down the west slopes of the Cascades. As the air descends, it compresses and heats up...leading to warmer temperatures along or near the foothills. In northwestern Washington, that's typically near Samish Bay, and between Mount Vernon and Arlington.