PNW Migration Update – 19 May 2013

Winds with a mainly northerly component did not deter this last wave of migrants.  Except along the coast where the winds were up to 20 knots at altitude.  The migration pattern was again a signature of this season – moderate with patches of heavy returns.  The bulk of the birds were flying up the flanks of the Cascades.  We did see a very light but widespread flight come up out of the area around the mouth of the Columbia – captured in the Regional Composite.

A high pressure cell off the coast is dictating the conditions currently — clear skies and northerly winds.  There is a low squished between two highs that has some moisture associated with it, but it doesn’t look very strong and may only bring some cloud cover.  Notable is the high out in the Gulf of Alaska.  When the high pressure cells reach that latitude, summer is not far behind, but at this time of the year it can also pull down some cold arctic air.

Nationally the strong low that is wreaking havoc across the Plains States also pretty much shut down the Central Flyway. Some opportunistic migration between or behind squalls can be seen. The Mississippi Flyway was hopping however, especially up the Ohio Valley.  We are now seeing patterns that indicate this season’s migration is beginning to wain – not over, but definitely on the back side of the peak.  For details on migration back East check out the NEXRAD trackers in the side bar.  For a look at last night’s migration on a national level take a look at Paul Hurtado’s archived loop here.

Admin Note:  There will only be two more updates this season – i’m headed out on my annual trip to Malheur with the folks from the Audubon Society of Corvallis.  I may put up the archived loops without commentary once i get back from Malheur – depends on how they look.  But other than that — barring a meltdown in conditions — i’ll be back in the fall to watch the new crop of birds pick their way south.

Left click for larger gallery view: