First image is of the winds aloft at 850 mb (approx 5000 ft). Second image is a snapshot of the base velocity showing north to south directionality at a peak of 20 to 25 knots. 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.) Note: last night RTX was down from about 11:30 pm last night so there are no images from then on. You can still see the nightly exodus though, starting at around an hour after sunset.
Sunset last night was at 8:35 pm pdst.
Fairly strong, up to 30 knot, northerly winds off the coast could have some migrants take advantage of them as they leave their breeding grounds in the arctic.
Overall density is still rather light but picking up.