10 October 2013 Migration Report

In spite of my Monday comments about shutting down early, i’m keeping the reports up until those Buffleheads show up like usual.  This fall’s migration still has some legs.

Another night of excellent conditions and another night of birds on the move.  From the US/CA border and down the I5 corridor birds filled the air space.    We had some stronger winds out of the WNW that kept the birds inland – very few were out over the ocean last night.

Looks like we have another couple of days until the next significant low moves in.  So we should see another good flight tonight.

With the discovery of the excellent (and i mean EXCELLENT!) weather site at the College of DuPage  I have added one of their radar products to the loops – HCA.  The HCA is explained in depth, with further linked resources, in a new page for the site. Look for it in the top banner with the other resources.  But basically it is, “The HCA is a complex algorithm performed by the NEXRAD that attempts to determine the most likely type of the echoes in the radar beam.”  And most importantly, for this blog, is that one of those echo types is classified as BI – biological.  When you look at the HC loops note the scale on the right, look for the BI color, and get ready for your jaw to drop!

If you have ever wondered why the TV weather man has radar images up that do not show the birds — the HCA is the answer.  They take the signal and eliminate unwanted echo classifications.  Here are last night’s loops – (man, i am so f’n stoked to have these archived again!)
Base Reflectivity - Portland (KRTX)
Base Velocity - Portland (KRTX)
HCA - Portland (KTRX)

Base Reflectivity - Gray's Harbor (KLGX)
Base Velocity - Gray's Harbor (KLGX)
HCA - Gray's Harbor (KLGX)

Base Reflectivity - Seattle (KATX)
Base Velocity - Seattle (KATX)
HCA - Seattle (KATX)

And Paul’s National Composite

Here’s the weather Gallery (left click for larger image):