Weds 09 May 2012 – PNW Migration Update

Locally migration continues. We had only moderate migration in the Portland Area last night.  It could be due to the northerly surface winds and the much heavier westerly winds aloft; 15 knots on the coast and increasing to 30 knots as you move inland. Again tonight, as we approach midnight, we see pulses of heavy migration in the southern valley between Eugene and Corvallis and a switch from yesterday, along the ridge of the Cascades.

In the field few reports came in for the local area. One report from Washington County had a Swainson’s Thrush as a new arrival.

The outlook remains favorable for migration.  The only issue remains to be the building NNW winds associated with the high pressure system.  They are forecasted to stay under 10 knots on the surface. However as we see from the 850 mb plot the winds aloft are quite a bit stiffer and this could be a limiting factor for the period.  We still expect some cloud cover through Thursday and that will keep things on the cool side. The weekend is forecasted to be an unseasonably warm couple of days.  Making for pleasant birding again.

Regionally we saw a heavy influx of birds over into the Rogue Valley again last night; keeping the well primed.  The Rogue River listserve is only reporting the rarities so I’m really not sure of migrant influx.  Last night the Pacific flyway had solid migration returns, a bit lower densities than last night, but still solid.  This can be seen on the National Composite as patches of blue from San Diego to Seattle.  You can also see the moderation in the KRTX (Portland) radar.

Nationally the front has moved east allowing nice flights up the Central Flyway, decent movement up the Mississippi, and catch as catch can further east behind the storms.  The southeast, ahead of the storms had some of the heaviest flights last.  Migrants are pushing north – it’s mid May and even adverse conditions are only moderating movement, not stalling it like last month.

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 this season!
New England – Tom Auer’s blog
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 this season!
Florida – Badbirdz Reloaded by Angel and Mariel Abreau
Continental US – eBird BirdCast Forecast & Report by Team eBird

Also under NEXRAD Trackers in the sidebar to the right.