[Fwd: Weather Service Feedback on Today's Trans-gulf Migration]
Tyler Bell (bell@say.acnatsci.org)
Wed, 25 Mar 1998 14:03:34 -0800
This is a multi-part message in MIME format.
--------------3794287E1717
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Here's an addendum to my previous post on Gulf migrants.
--
Good Birding! ...and all this science,
Tyler Bell I don't understand, It's
mailto:bell@say.acnatsci.org just my job five days a week.
California, MD Elton John (Rocket Man)
http://www.anserc.org/
--------------3794287E1717
Content-Type: message/rfc822
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
X-Mailer: Mozilla 3.0 (Win95; U)
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Message-ID: <35194EE0.5E0A@earthlink.net>
Date: Wed, 25 Mar 1998 12:37:20 -0600
Reply-To: birder@earthlink.net
Sender: Audubon birding discussion list for Texas
<TEXBIRDS@LIST.AUDUBON.ORG>
From: "E.G. White-Swift" <birder@EARTHLINK.NET>
Organization: Outback Communications
Subject: Weather Service Feedback on Today's Trans-gulf Migration
To: TEXBIRDS@LIST.AUDUBON.ORG
TexBirders:
I talked to Bill Read at the weather service's Western Gulf River
Forceast Center in Houston a few minutes ago. He and I have had
conversations over the last few years about Sid G's radar research and
Bill probably understands more about the radar out of Houston as it
effects birds than anyone I know. Here are a few of his comments:
~ He had independently commented to someone else in the weather service
office this morning that the radar imagry looked like a bird movement
across the gulf but he thought it was too early so he had passed it
off. He plans to watch the movement for the remainder of the day. His
comment, based on previous experience, is that it my be a hawk movement.
~ He made the following comments on how birders can best interpret the
nextrad pages:
1. Intellicast data is the cadilac of the industry..best resolution
2. Make sure the chart is showing the "Clear Air Mode"
3. The elevation, 0.5 degrees above the horizen, is the lowest elevation
they can use to scan the horizen to avoid ground clutter. It is
scanning from the radar site (which is not always in the same city for
which the site is issued).
4. The color bars indicate reflectivity, i.e., radar bounces off
objects(on most nextrad sites planes are computed out of the radar
image)
5. The sites have two bars:
The left side is negative reflectivity
The right side is postive reflectivity
The higher the number, the more concentrated the activity is
6. The best way to determine birds or butterfly movements is to look for
a radar image screen that has lots of speckles and a high number. A
solid mass of color is unlikely to be birds. The higher resolution the
image the better idea you will have of the amount of "speckling" going
on.
I hope this helps,
E.G. White-Swift
Central Texas Audubon
Waco, TX
--------------3794287E1717--