Thurs 08 Sept 2011

First image is of the winds aloft at 850 mb (approx 5000 ft). Winds over the state were light and variable.  There were some localized 20 knot easterlies on the east side but shouldn’t prove to be a migration barrier.  The strong 30 to 40 knot ESE winds continue up north and are more problematic for the pacific flyway.  They will move birds inland and stage them for the central flyways.

Second image is a snapshot of the base velocity showing north to south directionality at a peak of 15 to 20 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.)

Sunset last night was at 7:39 pm pdst.

The radar was in precipitation mode last night — probably because of the smoke from the fires in the Cascades.  Anyway, that makes it hard to get a handle on the relative density of nocturnal migration.  Exodus bloom about an hour after sunset was apparent – so birds are on the move.