19990302: AVN Thin Grids

>From: Brett Newkirk <address@hidden>
>Organization: .
>Keywords: 199903022256.PAA28160

>Hi-
>       I have a concern about the AVN Thin grids which we receieve from
>our ldm. Since about Feb 19, some of these grids have incorrect times
>stored in the GEMPAK headers. For example, todays case (99030212); if I
>want to plot using GDPLOT the surface pressure and use GDATTIM=first, it
>worked fine. However, if I use GDATTIM=f00, I get the error message that
>990302/1232F000 is an invalid time. The 1232 appeared in today's 12Z run
>instead of 1200. I have a series of programs that use GD_RDAT to read
>various grids and noticed that this was the time being read into the
>variable GDATTM(1) and consequently, GD_RDAT will not work. If you could
>please look into this problem with your copy of the AVN Thin grids it
>would be greatly appreciated.
>       Here at the University of Washington, we use dcgrib to decode the
>data and perhaps there is a problem with the grib file?
>Thank you for your help --
>Sincerely,
>Brett Newkirk
>Brett Newkirk    E-MAIL: address@hidden
>Office: ATG 424  Atmospheric Science/Geophysics Building
>Mailing Address: Department of Atmospheric Sciences, University of Washington
>                 Box 351640
>                 Seattle, WA 98195-1640
>Office Phone: (206) 685-2183
>

Brett,

I don't find any grids such as you mention above.
I posted our raw grib files for avn thin files at:
ftp.unidata.ucar.edu under /pub/chiz/

Can you try decoding the data in those files locally and
see if the same problem occurs?

If you don't have any problem with our files, then you probably
need to check your pqact.conf file entry to make sure only one
copy of dcgrib is writing out to the thin.gem files. Also
send me your pqact.conf entry so I can see if the pattern
we are using is more restrictive and filtering out bad grids.

NCEP has been doing alot of Y2K mods on the AVN, but I can't say I
see any effects here at this time.

Steve Chiswell