precipitation gfs grib with grib2ctl...

[claudio cortes]

Thanks Nakazawa-san...! It works...! but there are a problem, grads
shows the average between t1 and tn, not the accumulated
precipitation. In the grib2ctl home page says something about -0
gribmap option.

Quote:

"Note: grib files can have 1, 2 or 3 times associated with each
record. For example, an analysis will have only 1 time. However, a 24
hour forecast will have two times, the start time of the forecast and
the verification time (24 hours after the start time). Now the average
12-18 hour forecast precipitation will have 3 times: the start of the
forecast, the start of the averaging period and the end of the
averaging period.

Gribmap takes the GRIB file and finds the time and location of each
grib message and writes the essential information into an index file.
Now which time is used depends on the gribmap option: nothing or -0.
With no gribmap option, gribmap give the verification time or the end
of the averaging period. With a -0 option, gribmap uses the start time
of the forecast, analyses time or the beginning of the averaging
period..."

It's recomended to use -0 gribmap option...? (I have ententended that
-0 option is used for reanalysis, but exists another interesting
option: -t0)


2008/1/15, Tetsuo Nakazawa <nakazawa at mri-jma.go.jp>:
> Dear Claudio-san,
> I download the gfs grib datasets stored in:
> ftp://ftpprd.ncep.noaa.gov/pub/data/nccf/com/gfs/prod/gfs.yyyymmddhh/wafsgfs_P_hhz_intdskFF
>
> I apply:
>
> cat * > mydata.grb
> grib2ctl.pl -verf mydata.grb > mydata.ctl
> gribmap -e  -i mydata.ctl
>
> All variables seems OK in the map, but the precipitation doesn't show,
> grads only says "Cannot contour grid - all indefined values"
>
> What's wrong ? (perhaps grib2ctl doesn't support precipitation yet)
>
>  I am not familiar to the gfs dataset. But,
>  Precipitation would be forecast variable. Thus at t=0, there is no values
> at all grid points.
> However, if you set t=1, then I hope you may get the accumulated
> precipitation between t=0 and t=1.
>
> ********************************************
> Tetsuo Nakazawa
>                       nakazawa at mri-jma.go.jp
> Typhoon Research Department
> Meteorological Research Institute
> Tel:  029-853-8671 Fax: 029-853-8735
> ********************************************
>
>
>


--
Claudio Cortes
www.claudiomet.cl.nu

Meteorologo
Laboratorio de Meteorologia y Calidad de Aire
Centro Nacional del Medio Ambiente (CENMA)
--------------------------------------------------------------------------------------

Claudio Cortes
www.claudiomet.cl.nu

Meteorologist
Meteorology and Air Quality Labs
National Enviroment Center, Chile (CENMA)