Tues 16 april 2012 – PNW Migration Update

Well it looks like a high pressure ridge built yesterday providing the birds with a buffer between low pressure systems.  And, they took advantage of it, all up and down the Pacific Flyway!  Birds are on the migration train headed north from San Diego to Seattle.  Should be a good day for new arrivals.

In the field:Chipping Sparrows put in an appearance in Clackamas County; swallow numbers are way up at the McKinstry ponds.  On the listserves; House Wrens and Caspian Terns are being reported.  Southern Oregon coast had a large influx of new warblers

Regionally: as you can see from the KMAX/Medford radar, birds are moving in good numbers, and they are headed our way.

Nationally: as the cold front that spawned the extreme weather moves east, the back fill WNW winds are keeping migrations limited to the southern half of the country with some favorable conditions being found in New England and along the Atlantic seaboard.  The 850mb plot and the National composite tells the story quite well.  The animated radar loop for the composite can be found here

As always, for a more detailed analysis of the situation back east, check out the folks found on the sidebar to the right under NEXRAD Trackers.