Tues 27 Mar 2012 — PNW Migration Update

Locally a few migrants got off the ground ahead of the latest band of precipitation which came in from the SW.  Other than that not much made it into the area nor was the pipeline primed to our south.

I put in a regional composite so we can see the extent of the latest precipitation.  It is also a good look at the difference between the patterns made on the radar by clouds and rain vs. biological targets.  The precipitation shows up as a blocky and dense pattern seen over most of the western portion of the image.  Whereas the birds taking flight in font of the rain show up more stippled in pattern as can be see along the I5 corridor and a few spots further east like around Pendleton.

Nationally very little has changed as the low pressure systems are ever so slowly moving east.  A lack of large pressure differentials are keeping these systems in place and not creating much of a head wind up the Central Flyway until you get closer to the center of the lows and precipitation.  The only differences from yesterday are to be found on the trailing edges of the low hanging out on the eastern seaboard and locally in the north allowing nocturnal flight as weather permits.

The densities have picked up in the flights seen last night.

Local sunset last night was 7:32 PM PDST