Mon 10 Oct 2011

First image is of the winds aloft at 850 mb (approx 5000 ft). Winds over the state are moderate and out of the WNW at the base of the cold front hanging off of Vancouver Island.  Offshore winds are quite a bit stronger and out of the south.  That would deter any movement offshore.

Second image is of the surface winds and pressure.

Third image is the animated gif with snapshots every half hour of the base reflectivity above radar station RTX.  The radar went into precipitation mode last night at around 11 PM PDST so density readings are shifted a bit.  Then the local rains started around 3 AM.  There was very little nocturnal movement last night and most of it to our north.  Probably reshuffling rather than directional. When the rains showed up anything in the air put down.

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.)

We could very well be on the back end of this season’s migration.  The bulk of the the long-distance Neotropical migrants have probably already moved through and we’re now waiting on the short-distance birds more typical of late fall flights.  Since they don’t have far to go their departure is more dictated by temperature and food supply up north.

Sunset last night was at 6:36 pm pdst.