Fri 13 April 2012 – PNW Migration Update

Click on thumbnails to enlarge and animate.

Decent migration across the Pacific Northwest last night, especially up the I5 corridor to the north. The RTX station was in precipitation mode until the 11:33 return – probably due to a small squall that came up out of the SW and moved through Salem and McMinville from 7 to 9 last night. That little squall probably diverted some birds to the east initially due to the north winds associated with it – only a smattering of rain around 9. As the weather dissipates from 10 to 11 the birds are filling back in behind the cloud front and moving over the west counties. Still, looks like east counties got most of the love last night.

In the field: the first really large concentration of Cliff Swallows and a high Yellow-rumped count of approximately 20 birds was noted yesterday.
Regionallly: Medford was socked in under heavy cloud cover. I don’t see anything moving down there, even between the clouds. At the time of exodus the rain had stopped, but there was a light 10 mph head wind on the surface. Hard to say what’s happening under the clouds, but it doesn’t look like much. I really wish Eugene would get a radar on line! It’s like looking into a black hole south of mid-valley.  The California pipeline was shut down last night due to rain

Nationally: The Central Flyway, while seeing favorable winds, the birds are only moving as far north as the weather allows.  A series of storms from Nebraska to the Dakotas kept birds out of the area in the main.  The Mississippi Flyway on the other hand saw a marked increase in activity that pushed birds up the Ohio Valley as well — some happy migrant hunters over there this morning for sure.  The Atlantic Flyway will just have to wait it’s turn.

The animated National Composite can be found here.

Check out the NEXRAD Trackers back east for a more detailed discussion — found in the side bar to the right.