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Re: 20051206: Gempak to grib conversion of CED type grid

Kevin,

The specification for WMO grib table 131 would be inconsistent.
in VERCEN, the table version will default to 2, which is what would be
used to determine the parameter number for HGHT in wmogrib2.tbl.

The table 131 is a version number used for the reanalysis, but the 
realtime GFS certainly would be using version 2.

Steve Chiswell
Unidata User Support


On Thu, 2005-12-08 at 15:08, Kevin Hill wrote:
> Steve,
> 
> Thanks for the response. I tried changing the script to reflect the
> specifications that you suggested, but unfortunately I am still receiving
> errors when trying to run WRFSI. I am going to pursue help from the WRF
> help site as well. Here is the script that I ran with the changes you
> mentioned:
> 
> foreach level (1000)
> foreach parm (hght)
> 
> gdgrib << endin
> gdfile  = "gfs-avn-hi_3_20040911_0000_000.gem"
> gfunc   = hght
> gdattim = "040911/0000F000"
> glevel  = 1000
> gvcord  = pres
> gbtbls  = wmogrib131.tbl
> gbfile  = "gfs-avn-hi_3_20040911_0000_000.grb"
> vercen  = //96/0
> pdsval  =
> precsn  = d/6
> wmohdr  =
> cpyfil  = #003
> proj    =
> grdarea =
> kxky    =
> r
> 
> endin
> 
> end
> end
> 
> The changes that I made are under the parameter "vercen" and "cpyfil". I
> also specified the precision which I am fairly sure consists of 6 decimal
> places. Does this script look ok? Is there anything else I could be
> missing? Thank you very much!
> 
> Kevin Hill
> 
> > Kevin,
> >
> > the generating process ID of the GFS model is 96
> > http://www.nco.ncep.noaa.gov/pmb/docs/on388/tablea.html
> > The subcenter should be 0. This will identify the grid
> > as NCEP's GFS model.
> >
> > Most decoders do not care about a WMOHDR, which is only
> > used for broadcasting the data over the GTS.
> >
> > The cpyfil value is used to specify a grid number for PDS octet 7,
> > otherwise, the value of 255 (gds defined will be used). It may be
> > that your proprocessing is specifically looking for the PDS octet 7
> > to specifically identify itself as #003 rather than 255. The
> > GRIB from NCEP would definitely have a value of 3 in octet 7.
> >
> > Steve Chiswell
> > Unidata User Support
> >
> > On Wed, 2005-12-07 at 12:12, Kevin Hill wrote:
> >> Steve,
> >>
> >> Thanks for the quick reply. I guess I was under the impression that
> >> those
> >> values were either not necessary to set or were set by comparing to the
> >> cpyfil. In general the only parameters that I am unsure how to set are:
> >>
> >> VERCEN
> >> WMOHDR
> >>
> >> Do you have any idea of what those should be set to in order to
> >> replicate
> >> the values that are found in the gfs-avn 1 degree analysis? The data I
> >> am
> >> using is available at the following website:
> >>
> >> http://nomads.ncdc.noaa.gov/data/gfs-avn-hi/
> >>
> >> Thanks, I really appreciate your help.
> >>
> >> Kevin
> >>
> >>
> >> > Kevin,
> >> >
> >> %3