A better way to download: Was Re: g2ctl (not making .idx file)

Wesley Ebisuzaki Wesley.Ebisuzaki at NOAA.GOV
Mon Jun 22 11:08:35 EDT 2009


   This post is not meant to criticize your script; everybody has
scripts that work but
not optimally.  I just want to point out to other subscribers that they
are other options.

(1) GRIB2

Nobody likes changing formats (grib1 -> grib2) but moving to grib2 has many
carrots and a stick.

    (1) data is compressed so files are smaller
    (2) the operational nomads (nomads.ncep.noaa.gov) has 24x7 support
with 4 physical servers
             at two sites.  the operational nomads site only supports
grib2.  nomad5 is a single machine
             (no backup) with business hours support.
    (3) regional subsetting on the nomads server is better with grib2
(newer code)
    (4) the development nomad systems have grib1 versions of the
operational forecasts because
          it takes time for people to convert codes. Eventually the
service will be discontinued.

(2) the use of the ftp server.
      FTP servers are a pain.  Little to no support on the development
nomad systems.
      I suggest that you use the http server instead.   ftp://nomad5...
-> http://nomad5...

(3) Downloading the entire file.
      Do you really want to download the entire forecast file?  How much
of the file
      do you really need?  The http protocol allows you to download
selected grib
      messages once you know the byte range ("partial http
downloading").  See


For must people who want to download the GFS forecasts, (1) and (3) are good
things to do.  Sites that support (1) and (3) with the GFS files include


   Wesley Ebisuzaki

Rafael Mundaray wrote:
> I have this to make a file named GFSall_TIMES:
> fecha=""
> fecha=$(date '+%Y%m%d')
> pwd
> cd /home/rmundaray/Escritorio/SALIDAS_MODELOS/GFS/
> mkdir "$fecha"_00Z_GFS
> cd "$fecha"_00Z_GFS
> cp ../wgrib .
> cp ../grib2ctl.pl .
> cp ../gribmap .
> wget ftp://nomad5.ncep.noaa.gov/pub/gfs/gfs"$fecha"/gfs.t00z.pgrbf00
> wget ftp://nomad5.ncep.noaa.gov/pub/gfs/gfs"$fecha"/gfs.t00z.pgrbf03
> wget ftp://nomad5.ncep.noaa.gov/pub/gfs/gfs"$fecha"/gfs.t00z.pgrbf06
> wget ftp://nomad5.ncep.noaa.gov/pub/gfs/gfs"$fecha"/gfs.t00z.pgrbf09
> wget ftp://nomad5.ncep.noaa.gov/pub/gfs/gfs"$fecha"/gfs.t00z.pgrbf12
> wget ftp://nomad5.ncep.noaa.gov/pub/gfs/gfs"$fecha"/gfs.t00z.pgrbf15
> wget ftp://nomad5.ncep.noaa.gov/pub/gfs/gfs"$fecha"/gfs.t00z.pgrbf18
> wget ftp://nomad5.ncep.noaa.gov/pub/gfs/gfs"$fecha"/gfs.t00z.pgrbf21
> wget ftp://nomad5.ncep.noaa.gov/pub/gfs/gfs"$fecha"/gfs.t00z.pgrbf24
> wget ftp://nomad5.ncep.noaa.gov/pub/gfs/gfs"$fecha"/gfs.t00z.pgrbf72
> (Try with this...)
> *./grib2ctl.pl -verf gfs.t00z.pgrbf%f2 > GFSall_TIMES_"$fecha".ctl
> ./gribmap -i GFSall_TIMES_"$fecha".ctl*
> --
> Ing. Rafael E. Mundaray M.

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