The reason? There is cold air and higher pressure in eastern Washington and lower pressure west of the Cascade crest (see forecast map for 10 AM Saturday AM to see this). Big pressure difference along the crest, with a 10 hPa (mb) difference between Seattle and Yakima. Air loves to accelerate from high to low pressure in terrain gaps, producing very strong winds on the western side of the Columbia Gorge.
Consider the winds at one of my favorite locations, Vista House, position above the Gorge at Crown Point (see picture).
Here are the winds there today at Vista House. Sustained 40 mph with gusts reaching over 77 mph earlier today. That would get your attention!
The extraordinarily fine late November weather will continue the next week. Really, it is a gift to get such a dry, sunny period this time of the year. Here is the forecast rainfall over the next 72h. Oregon and Washington will get nearly nothing, with the exception of a passing blow to the NW coast.
is working on your hot tub....you will need it.
Because of the weather next week, Californians will need some very large heaters for their hot tubs.