[Met_help] Copygb usage

[John Halley Gotway]

David,

Just to let you know, I do not generally provide support for the copygb utility.  However I do provide support for the Model Evaluation Tools (http://www.dtcenter.org/met/users/) which is a
verification package for the NWP modeling community.  Several MET users make use of the copygb utility for regridding their GRIB1 datasets output from the WRF model/WRF PostProcessor.

But the answer to your question is no, copygb does not currently support GRIB2 files.  And to my knowledge NCEP hasn't provided a version that does.

Here's the usage statement for copygb:

Usage: copygb [-g "grid [kgds]"] [-i "ip [ipopts]"] [-k "kpds"] [-v "uparms"]
              [-B mapgrib [-b mapindex] [-A "<> mapthreshold"] [-K "mapkpds"]]
              [-M "mask"/mergegrib [-m mergeindex]] [-X] [-a] [-N namelist]
       then either:
              grib1 index1 grib2
            or:
              -x grib1 grib2

The "grib2" in there is a little misleading.  The usage statement uses "grib1" and "grib2" to indicate file1 and file2, not to imply that it supports the GRIB2 file format.

So in order to use copygb, you'd first need to convert the GFS GRIB2 files back to GRIB1 format.  NCEP does provide a utility that does this called "cnvgrib": http://www.nco.ncep.noaa.gov/pmb/codes/GRIB2/
But you'll need to download and build this code locally.

Once you do get your data in GRIB1 format and begin using copygb, I've found the file "copygb.doc" (distributed with copygb in "sorc/copygb/copygb.doc") to provide the most useful help information.

Hope that helps!

John Halley Gotway
johnhg at ucar.edu

David Allen wrote:
> Hello John,
> I am having a few issues using copygb and I saw that you have helped others
> in the past.
> 
> I have installed copygb from the following source
> http://www.cpc.noaa.gov/products/wesley/copygb.html.
> 
> I then tried to run the following command on the attached grib file:
> copygb -xg"255 0 740 460 -55000 96000 8 -9000 -170000 100 100 64"
> gfs.t18z.master.grbf00.10m.uv.grib2 out.grib
> 
> The running of this command outputs the following error:
>  getgb1s: prog error bufsiz= 0
> STOP 7
> 
> Are you able to tell me what I am doing wrong? The problem could relate to
> one of the following: my version of copygb, the grib file (it is grib2) or
> the parameters I am entering.
> 
> I would really appreciate your help as I have been trying for sometime to
> get copygb working.
> 
> Many thanks
> 
> David Allen
> 
> 
>