Re: Sample GFS 1x1 deg cdl

On Fri, 23 Jan 2004, Jim Cowie wrote:

>
> Brian,
>
> I've attached a sample CDL for the NCEP GFS 1x1 deg grid (AKA grid 3)
> which we get off the NCEP ftp server. I don't know if it will work with
> what comes through AWIPS but it is a start. I also have CDLs for the
> GFS 2.5x2.5 grid (grid 2) and the Eta 211 grid if you want them.
>
> The gfs_003.cdl has most or all of the fields defined but many commented
> out since we don't use them. Also note that though we use gribtonc, we
> had to make a few changes to it to handle some of the time averaged
> or time accumulated variables better. gribtonc doesn't handle these
> very well. (We're hoping that the new gribtonc, currently under
> development at Unidata, will.)

Jim,

Thanks for responding to the email. I'm curious about what time
averages/variables are you talking about? DOn't want to skip it in the new
gribtonc.  I haven't worked on the new decoder for the past 2 months,
other stuff but I've put it back on the agenda near the top. I've decoded
the National Digital Forcast DB stuff but I'm working on the eta in grib2
that has png compression.

Robb...


>
> Hope this is usefull to you,
>
> -jim
>
> --
> Jim Cowie
> NCAR/RAP
> address@hidden
> 303-497-2831
> ----------------------------------------------------------------------
>
> HOETH, BRIAN R. (JSC-ZS) (LM) wrote:
> > Hello,
> >
> > I would be interested in seeing the wrf249.cdl file also.  For that matter,
> > I would like to see any cdl files that people have created in their
> > experiences with using gribtonc, other than the default cdl files that come
> > with the package.  I am especially interested in finding out if anyone has
> > tried creating AWIPS displayable netCDF files for GFS 1x1 degree data using
> > gribtonc.
> >
> > Example GFS 1x1 degree data from today can be found at:
> > ftp://tgftp.nws.noaa.gov/SL.us008001/ST.opnl/MT.avn_CY.00/RD.20040123/PT.gri
> > d_DF.gr1/
> >
> > Thanks,
> > Brian Hoeth
> > Spaceflight Meteorology Group
> > Johnson Space Center, Houston, TX
> > Office:  281-483-3246
> > Operations:  281-483-1051
> >
> >
> > -----Original Message-----
> > From: address@hidden
> > [mailto:address@hidden]On Behalf Of Robb Kambic
> > Sent: Thursday, January 22, 2004 5:53 PM
> > To: Rorik Peterson
> > Cc: address@hidden; decoders
> > Subject: Re: confusion with record dimension using gribtonc
> >
> >
> > On Thu, 22 Jan 2004, Rorik Peterson wrote:
> >
> >
> >>I have been having some problems with the record dimension when
> >>decoding  Alaska-region GRIB data obtained via ftp from NCEP at:
> >>
> >>ftp://ftpprd.ncep.noaa.gov/pub/emc/mmb/mmbpll/alaska10.t00z/
> >>
> >>The GRIB files available here are updated daily, each one corresponding
> >>to a forecast time (0-48 hours).  I sequentially process them with
> >>'gribtonc' into a single netCDF file
> >>
> >>[/user2/ldm/AWIPS]$ perl -e 'foreach(glob "A*"){ `gribtonc wrf249.cdl
> >>out.nc < $_`;}
> >>
> >>However, I always have a complete record of missing data somewhere in
> >>the middle.  Using today's data, I narrowed it down to when I added the
> >>15-hour forecast file; at which point two records were added instead of
> >>one, and the last one was completely empty.
> >>
> >>Here I decode just one GRIB file:
> >>[/user2/ldm/AWIPS]> rm out.nc;gribtonc wrf249.cdl out.nc < AWPREG15.tm00
> >>
> >>Then dump the pertient information of what is in there
> >>[/user2/ldm/AWIPS]$ ncdump -v valtime_offset out.nc | egrep "record =
> >>UNLIMITED|valtime_offset ="
> >>        record = UNLIMITED ; // (2 currently)
> >> valtime_offset = 15, 15 ;
> >>
> >>and then look at the data
> >>[/user2/ldm/AWIPS]$ ncks -H -v u -d x,100,100 -d y,100,100 -d level,4,4
> >>out.nc
> >>level[4]=500
> >>
> >>record[0] level[4]=500 y[100]=986.789 x[100]=986.789 u[540324]=2.17085
> >>record[1] level[4]=500 y[100]=986.789 x[100]=986.789 u[1673253]=-9999
> >>
> >>x[100]=986.789
> >>
> >>y[100]=986.789
> >
> >
> > Rorik,
> >
> > You already narrowed the problem down to either a bad data product or an
> > error in gribtonc.  First test would be to run gribtonc with the -v and
> > -l - flags, ie gribtonc -v -l -  .....    Hopefully this should shed some
> > light on the error. Next test would be to use gribdump to check if there
> > is an unusual header in the grib products.  In my recent work, I've found
> > a wrong header on only one product in a group of 2000 files. The
> > projection was wrong on the product.  ie gribdump -h <gribfile>
> >
> > Can you send me the wrf249.cdl file you are using so I can use it.
> >
> > I downloaded the AWPREG15.tm00 file and will let you know the results.
> >
> > Robb...
> >
> >
> >>You can trust me that the entire second record is full of -9999, which
> >>is missing_value.  Is this a problem with the GRIB data, or gribtonc?
> >>All the GRIB files are the same size, more or less, so I don't know
> >>where the second set of (missing) data is coming from.  Any insight in
> >>what to look at next is appreciated.
> >>
> >>rorik
> >>
> >>
> >>
> >
> >
> > ============================================================================
> > ===
> > Robb Kambic                            Unidata Program Center
> > Software Engineer III                          Univ. Corp for Atmospheric
> > Research
> > address@hidden                 WWW: http://www.unidata.ucar.edu/
> > ============================================================================
> > ===
>

===============================================================================
Robb Kambic                                Unidata Program Center
Software Engineer III                      Univ. Corp for Atmospheric Research
address@hidden             WWW: http://www.unidata.ucar.edu/
===============================================================================