trouble with using template with forecast files

Roz MacCracken rozmac at IGES.ORG
Thu Oct 16 13:29:34 EDT 2008


Hi Jennifer,

Thanks.  That worked for the one day...but, I have a dataset from Oct 1
- 16 (actually, it's bigger than that...).

I tried doing:
TDEF 105 linear 00z01oct2008 6hr               (for   105 = 7 files per
day * 15 days)
and that didn't work..."Undefined grid".

What kind of TDEF do I use for a long time series of data?

also, in my grads script, how do I indicate that I want to use forecast
times?  (i.e., "set time blah?")

Roz

Jennifer Adams wrote:
> Hi, Roz --
> Your templated descriptor file should have the following entries:
>
> DSET ^%iy4%im2%id2%ih2.AWIPSF%f2.tm00.sg
> OPTIONS template
> TDEF 7 linear 00z14oct2008 6hr
>
> I feel it's worth the effort to make your metadata as accurate as
> possible. Use an accurate number of time steps -- why say you have 999
> time steps when in reality you only have 6? Actually, the correct way
> to set up this forecast data set is to put 7 in the TDEF entry because
> the 00hr time step, although not present in your list of data files,
> is essential for resolving the %iy, %im, %id, and %ih substitution
> strings properly in your file names. Plus it just makes sense to have
> the first time step of your forecast data set be the initialization
> time, even if you don't have any data. GrADS will just set the first
> time step to missing -- you'll need to 'set t 2' before being able to
> display a variable. Don't forget you must also rerun gribmap if you
> change any of the grid definition or variable entries in your
> descriptor file. Use the -v option with gribmap and check to make sure
> everything is matching properly for each data file.
>
> --Jennifer
>
>
>
>
> On Oct 16, 2008, at 12:08 PM, Roz MacCracken wrote:
>
>> Hi All,
>>
>> I am trying to create a templated control file for a couple of forecast
>> files.
>>
>> I have files with the name:
>> 2008101400.AWIPSF06.tm00.sg - 2008101400.AWIPSF36.tm00.sg (there are
>> 6 files
>> total).  I have created control files called:
>> eta6.awipsf06.ctl - eta6.awipsf36.ctl  (mainly because I can't get the
>> %f2 option to work in my grads scripts.)
>>
>> Then, I created an index file called eta6.awipsf06.idx, using:
>> gribmap -i eta6.awipsf06.ctl,
>> which was created without errors.
>>
>> I can display data using the respective control file, pointing
>> at the corresponding index file.  (this is without templating).  So,
>> the control files do display data without templating.
>>
>> I have changed the dset line in the control file to:
>> dset ^%y4%m2%d2%h2.AWIPSF06.tm00.sg, changed tdef to 999,
>> and have added the "options template" to the control file.
>>
>> I have 2 questions..fairly easy, but, I can't get this to work...
>>
>> First, when I change the control file to the dset, and "options template"
>> above, and "set t 1", I get the error, "Undefined Grid", with no data.
>> Is there something that I've missed doing in my control file so that
>> I can display data using a template?
>>
>> Should I have changed the dset to %y4%m2%d2%h2.AWIPSF%f2.tm00.sg?  And,
>> if this is a better way, how do you set the date within a
>> grads script to get it to display the forecasted time?
>> (i.e., "set time 12Z14Oct2008(f=12)"...that may not be right...)
>>
>> Thanks.
>>
>> Roz MacCracken
>>
>> Sample of part of the control file:
>>
>> dset /ETA6/%y4%m2/%y4%m2%d2%h2.AWIPSF06.tm00.sg
>> index /ETA6/ctl/maps/test.AWIPSF06.tm00.sg.idx
>> undef 9.999E+20
>> title 2008100100.AWIPSF06.tm00.sg
>> *  produced by grib2ctl v0.9.12.5p41
>> dtype grib 212
>> options template
>> pdef 185 129 lcc 35.0 -95.0 105 49 25 25 -95 40635 40635
>> xdef 181 linear -140 0.5
>> ydef  91 linear  15 0.5
>> tdef 100 linear 00Z01oct2008 1dy
>> zdef 1 linear 1 1
>> vars 31
>> ACPCPsfc  0 63,1,0  ** surface Convective precipitation [kg/m^2]
>> ALBDOsfc  0 84,1,0  ** surface Albedo [%]
>> APCPsfc  0 61,1,0  ** surface Total precipitation [kg/m^2]
>> BGRUNsfc  0 234,1,0  ** surface Baseflow-groundwater runoff [kg/m^2]
>> CAPEsfc  0 157,1,0  ** surface Convective Avail. Pot. Energy [J/kg]
>> CFRZRsfc  0 141,1,0  ** surface Categorical freezing rain [yes=1;no=0]
>> CICEPsfc  0 142,1,0  ** surface Categorical ice pellets [yes=1;no=0]
>> CNWATsfc  0 223,1,0  ** surface Plant canopy surface water [kg/m^2]
>> CRAINsfc  0 140,1,0  ** surface Categorical rain [yes=1;no=0]
>> etc....
>
> --
> Jennifer M. Adams
> IGES/COLA
> 4041 Powder Mill Road, Suite 302
> Calverton, MD 20705
> jma at cola.iges.org <mailto:jma at cola.iges.org>
>
>
>



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