RE: NEXRAD stations

• To: "'Jeff Masters'" <jmasters@xxxxxxxxxxxxxxxx>, <ldm-users@xxxxxxxxxxxxxxxx>
• Subject: RE: NEXRAD stations
• From: "Dan Vietor" <devo@xxxxxxxxxxxxx>
• Date: Tue, 9 Jan 2001 15:03:32 -0500

> I am cheerfully watching the NEXRAD data flow in here, it is
> great to see!
>
> However, I am seeing some products from stations that are not
> in my WXP
> rad.cty list of stations:
>
> FFG
> GID
> LMK
> TOP
> UNR
>
> TOP is easy to guess, it is TWX (Topeka). Can anyone shed light on the
> rest of these?

WXP uses the official NWS identifiers for the Nexrad sites and not the
identifier for the WFO.  This is for consistency with RCM, MDR and other
radar products.

BTW, I don't find any sites with FFG.  There is Atlanta which is FFC.

I file Nexrad sites by the ID listed in the AWIPS header and not the WMO
header:

** SDUS51 KPHI 091837 ***
N0RDIX

I file on the DIX, not the PHI.  Here is my pqact.conf line:

#
# Radar - NIDS
WMO     ^SDUS5. .... ([0-3][0-9])([0-2][0-9])([0-5][0-9]).*/p(...)(...)
        PIPE    -close /home/ldm/bin/ucnids -c -
/home/ldm/data/nids/\5/(\1:yy)(
\1:mm)\1\2\3_\4.nid

> Also, in clear air mode, how can you have a negative
> reflectivity? Is a negative return ever really due to
> precipitation?

Its possible for snow but not rain.  Some types of snow have a very
small cross-section exposed to the radar beam.  This means it will
rarely have Dbz returns in the positive area.  The problem is that there
are a lot of other things that return Dbz values of 5 or less, like
birds, insects, clouds, ground clutter.  So you have to know what your
looking for.
________________________________________________________
Daniel Vietor               Mail: devo@xxxxxxxxxxxxx
Unisys Corp                 Title: Engineer/Meteorologist
221 Gale Lane               Phone: 610-925-5206
Kennett Square PA 19348     Fax: 610-925-5215

• Follow-Ups:
  • Re: RE: NEXRAD stations
    • From: Thomas L. Mote

• References:
  • NEXRAD stations
    • From: Jeff Masters