First image is of the winds aloft at 850 mb (approx 5000 ft). Winds over the state were light and variable. Strong wsw, up to 40 knots, to the north continue and will probably keep migrants up there grounded or push them over to the central flyway.
Second image is a snapshot of the base velocity showing directional movement, mostly north to south east. Perhaps what movement we do have the migrants are moving into the Cascades and following them down south.
Third image is an animated gif with snapshots every half hour of the base reflectivity above radar station RTX. Animation runs from around 8:00 pm pdst yesterday evening through 5:00 am pdst this morning. (Click on the thumbnails to view the full-sized images and animation.)
Sunset last night was at 8:05pm pdst.
Reflectivity continues to be light but much heavier up in the Puget Sound. Below are two regional base reflectivity images. One just before sunset the other around 11 pm pdst. These show two elements: first is the migration bloom after sunset, second is the difference in densities around the different radar stations. Could it be that many of the migrants are staging in the Puget Sound area?