Fri 30 Mar 2012 – PNW Migration Update

Rain and more rain on the way.  Heavy bands of precipitation from San Fransisco to Seattle continue to keep migrants at bay.  Light movement in central and southern California.

However, some birds are getting through in between the showers as local reports continue to come in of Osprey and Rufus Hummingbirds.  From my own observations over the last week,: most of the Scaup are gone from the Columbia, the Snow Goose count is way down on Sauvie Island, duck composition is in flux, no less than six Osprey were in the Scappoose bottoms, and no Sandhill Cranes were to be heard in the area.

Nationally the interplay of wind and weather with the birds is evident.  There are a few spots where weather is stopping advancing flights.  Take a look at the National composite and note the band of precipitation stretching from OK to MN.  Along the front of that system birds are running into the weather an putting down.  Same thing along the eastern seaboard where it is strong northerly winds that the birds are running into as can be seen in the 850mb plot.  This will certainly concentrate migrating birds.