21 May 2012 – PNW Migration Update

If you look at the two wind maps you can see the low pressure system building offshore to our NW.  the leading edge of this system is bringing the rain and SW winds.  As long as the rain remains light to intermittent the birds will continue north. Locally migration was moderate with heavy localized movement along favored routes

In the field the listserve migration chatter is dying down as we pass peak migration.  Pewees and Willow Flycatchers are being noted more frequently and the residents are settling in.  Including the Sandy River’s Eastern Kingbirds.  Check out eBird for Multnomah and Washington Counties.

The outlook for migration over the next few days remains dependent on the timing and occurrence of rain.  The wind is forecasted to remain out of the SSW over the next couple of days.  But as the front moves east we will be in the lee and that means rain and northerly winds.  How that effects migration depends on intensities.  Current forecast has this set for mid to late in the week.

Regionally migration in the Rogue Valley was also moderate with pockets of heavy movement.

The southern portion of the Pacific Flyway has pockets of heavy migration from San Diego to Redding.  It does appear that SoCal had a bit of moderation however.  Could be local conditions or a tapering off of migrant flow.

Nationally the weather continues to favor the Central Flyway and eastern portions of the Mississippi Flyway ahead of the front. We find the birds are still heavily pouring in from Mexico, but maybe not as widespread.  The Great Plains’  radars have decent returns from Brownsville to Minot.  The western, and especially the northwestern portion of the Mississippi flyway had a significant decrease in density last night due to some 20 – 30 knot WNW winds associated with the back side of the storm.

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

Wisconsin and New Jersey – woodcreeper  by David LaPuma
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!
Pac NW – Birds Over Portland by Greg Haworth
Continental US – eBird BirdCast Forecast & Report by Team eBird

Also under NEXRAD Trackers in the sidebar to the right.