Thurs 10 May 2012 – PNW Migration Update

Admin Notes: I’m not sure what was happening aloft as there seems to be a data glitch in the UCAR system and it is stuck on May 1st.  Which i just now noticed!!  Doh!  So there are no wind plots today and all of those since the second are the same. I’ll look for a back-up data source in the next few days.  Also i’m still looking into getting the timing fixed on the local radar loops, sigh, technology beyond my meager skill set.  UPDATE: i found a reasonable back-up for the 850 mb winds – now attached.

Locally migration was pretty much shut down last night. We had minimal migration in the Portland Area last night.  It’s probably due to the substantial northerly winds. By mid afternoon yesterday the winds picked up to a sustained 15- 20 knots.  They subsided by 10 PM but by then I guess the birds decided to spend the night and go for the next leg north another day.  The good news is, nobody left the area, so there’s still quite a few birds out there.  Probably a bit more dispersed, but the usual haunts should be rewarding.

In the field a few reports came in for the local area. Swainson’s Thrush are becoming more common, a Yellow Warbler was noted.  The vanguard migrants are now being joined by the laggards and are noted in larger flocks.  Still no significant local Bunting reports.

The outlook is questionable for migration.  The issue continues to be the building NNW winds.  They are forecasted to stay under 10 knots on the surface today, but they said that yesterday too. I can’t get a look at the 850 mb plot so I’m not sure what’s forecasted up there at the friction zone.  The clouds should remain minimal today with temperatures on the mild side. The weekend is still forecasted to be an unseasonably warm couple of days.  Making for a pleasant weekend of birding again.

Regionally we saw another heavy influx of birds over into the Rogue Valley again last night; keeping the well primed.  The Rogue River listserve was reporting some nice migrant influx yesterday.  Multiple reports of large warbler flocks with Yellow being in the mix.  Singing Buntings and a host of the usual suspects.  Close examination of a loop from the KMAX station shows most movement into the area and only a small, and abbreviated, pulse north toward Redmond.  So it should be pretty birdy down there today.

Last night the southern portion of the Pacific flyway had solid migration returns.  Densities picked up last night, and many areas filled in.  This can be seen on the National Composite as streaks of blue and patches of green from San Diego to Medford.  You can also see the lack of significant returns from Roseburg north to Seattle.

Nationally the major front has moved a bit further east and the storms are pounding the Mid-Atlantic and Northeast coast.   Significant northerly flow east of the Mississippi kept migration minimal across most of the east.  But the southerly flow up the Central Flyway was a free ticket and the birds took to the air from Texas to the Dakotas – clearly seen on the national mosaic.  I always get a kick out of watching the composite loop that Paul Hutado archives.  There is a permanent link to the right under “Weather”, so be sure to check that out.

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.