Friday 25 May 2012 – PNW Migration Update

The low pressure system that has been bringing this rain is completely disorganized and we have some terribly unsettled conditions; even spawning a funnel cloud yesterday in the valley.  If you take a look at the local and regional reflectivity loops, you will see cloud movement from east to west last night over the PNW – that happens maybe once a year.  The high pressure ridge organizing off the California coast is being felt in the northerly winds across the region and throughout the southern portion of the flyway.  Last night moderate migration was detectable between the clouds and rain for a very brief time.   Tellingly, the heaviest movement was to our north as seen on the Seattle radar.

In the field the migration news on the listserves shows some migrants still around and a few rarities. The Rogue’s Stork’s provenance and a Common Grackle, and a Rose-breasted Grosbeak on the Coast. Checking in on eBird for Multnomah and Washington Counties arrivals, we find nothing new in the area.

The outlook for migration over the next few days continues to be dependent on the timing and occurrence of rain and, most importantly – a supply of birds.  The forecast is for mixed weather through the weekend.

Regionally migration in the Rogue Valley was indiscernible.  I’m pretty sure the bulk of the migrants have moved through and all that is left are the late arrivals, a few strays and a couple of stragglers – the migrant well is drying up.

The Californian portion of the Pacific Flyway has a couple of pockets of heavy migration around the Central Valley.  I’m not sure what’s up with those birds.  Overall however, the migrant blooms are moderating.

Nationally – read yesterday’s description, it’s the same today.

As always — For more detailed migration updates in other regions check:

Wisconsin and New Jersey – woodcreeper  by David LaPuma (currently on hiatus – 5/21)
Michigan’s Upper Peninsula – The Northwoods BIRDAR by Max Henschell <- NEW!
New England – Tom Auer’s blog
Florida/SE – Badbirdz Reloaded by Angel and Mariel Abreu
PA/Ohio Valley – Nemesis Bird by Drew Weber
NW Ohio – Birding the Crane Creek by Kenn Kaufman
Arizona – Words About Birds by Tim Schreckengost <- NEW!
New Mexico – Albuquerque Birding by Matt O’Donnell <- NEW!
Continental US – eBird BirdCast Forecast & Report by Team eBird

Also found under NEXRAD Trackers in the sidebar to the right.