[Met_help] [rt.rap.ucar.edu #76163] History for Poinstat error

Mon May 16 09:34:22 MDT 2016

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  Initial Request
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Greeetings.

When I run pointstat toll using ECMWF data I get empty files.  To format the ECMWF data to the required format I used grib_set and grib_copy commands which are part of grip_api tools. Please check my input files in the following directory  /incoming/irap/met_help/phaduli_data

Thank you inadvance

Elelwani Phaduli
Scientist :Short and Medium Range Forecasting
South African Weather Service
442 Rigel Ave South
Bolepi House
Tel: 012<Tel:012> 367-6200

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  Complete Ticket History
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Subject: Poinstat error
From: Julie Prestopnik
Time: Fri Apr 29 15:24:48 2016

Thank you for uploading your files to our ftp site.

First, I see that your observation NetCDF file is actually a grib file
and
appears to be the same as your ECMWF file that you uploaded.  Perhaps
you
uploaded the grib file also as synop.2016030112.nc.

Regardless, met-5.1 does not include support for the ECMWF usage of
GRIB.
We realize this is a shortcoming of MET and our next release will
include
more support for ECMWF files.  In the meantime we have a workaround
that
you can use so that MET can read your ECMWF GRIB file.

In order to determine if MET could read the GRIB file, I ran
plot_data_plane.  First I ran wgrib to see what was in the file and to
get
the parameter table version number:

*wgrib -V ecmwf_2016030100UTC_verif.grb*

rec 1:0:date 2016030100 TMP kpds5=11 kpds6=105 kpds7=2 levels=(0,2)
grid=255 2 m above gnd 12hr fcst:
  TMP=Temp. [K]
  timerange 0 P1 12 P2 0 TimeU 1  nx 161 ny 129 GDS grid 0 num_in_ave
0
missing 0
  center 98 subcenter 0 process 145 Table 3 scan: WE:NS winds(N/S)
  latlon: lat  -21.000000 to -37.000000 by 0.125000  nxny 20769
          long 15.000000 to 35.000000 by 0.125000, (161 x 129) scan 0
mode
128 bdsgrid 1
  min/max data 287.652 313.472  num bits 12  BDS_Ref 287.652  DecScale
0
BinScale -7

I could see that it is using parameter table version 3.  If we try
running
plot_data_plane in the following way:

*plot_data_plane ecmwf_2016030100UTC_verif.grb out.ps <http://out.ps>
'name="TMP"; level="Z2"; GRIB1_ptv=3;'*

DEBUG 1: Opening data file: ecmwf_2016030100UTC_verif.grb
ERROR  :
ERROR  : VarInfoGrib::set_dict() - unrecognized GRIB1 field
abbreviation
'TMP' for table version 3
ERROR  :

We see that it is unsuccessful, which is due to the lack of support
for
ECMWF files.  However, the workaround is to modify the GRIB tables
used by
MET.

The GRIB1 tables used by MET are stored in this file:
   met-5.1/data/table_files/nceptab_flat.txt

The GRIB2 tables are here:
   met-5.1/data/table_files/grib2_vars_flat.txt

When you run "make install" those files get copied over into this
directory:
   {prefix}/share/met/table_files

Where {prefix} is the installation directory.  At run time, the MET
tools
read those files from the installed "share" directory.

Here is what I recommend that you do:

(1) Edit the file "nceptab_flat.txt".  Add the line:
      11 3 "TMP" "Temperature" "K"

(2) Copy that file into the "share/met/table_files" directory...
either manually
or by running "make install".

(3) Try running the following command to make sure it works:
*plot_data_plane ecmwf_2016030100UTC_verif.grb out.ps <http://out.ps>
'name="TMP"; level="Z2"; GRIB1_ptv=3;'*

The GRIB1_ptv instructs MET to use the parameter indicator 11 and
parameter
table version number 3 for TMP.  The result of that job will be a
postscript plot of that data.  You can use the same settings in the
PointStat config file.

I was able to successfully run plot_data_plane after making the
changes to
the nceptable_flat.txt file.

*plot_data_plane ecmwf_2016030100UTC_verif.grb out.ps <http://out.ps>
'name="TMP"; level="Z2"; GRIB1_ptv=3;'*

DEBUG 1: Opening data file: ecmwf_2016030100UTC_verif.grb
DEBUG 1: Creating postscript file: out.ps

I hope that helps.  Please let us know if you have any other
questions.

Thanks,
Julie

On Fri, Apr 29, 2016 at 9:27 AM, Elelwani Phaduli via RT
<met_help at ucar.edu>
wrote:

>
> Fri Apr 29 09:27:42 2016: Request 76163 was acted upon.
> Transaction: Ticket created by Elelwani.Phaduli at weathersa.co.za
>        Queue: met_help
>      Subject: Poinstat error
>        Owner: Nobody
>   Requestors: Elelwani.Phaduli at weathersa.co.za
>       Status: new
>  Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=76163 >
>
>
>
> Greeetings.
>
> When I run pointstat toll using ECMWF data I get empty files.  To
format
> the ECMWF data to the required format I used grib_set and grib_copy
> commands which are part of grip_api tools. Please check my input
files in
> the following directory  /incoming/irap/met_help/phaduli_data
>
> Thank you inadvance
>
> Elelwani Phaduli
> Scientist :Short and Medium Range Forecasting
> South African Weather Service
> 442 Rigel Ave South
> Bolepi House
> Tel: 012<Tel:012> 367-6200
>
>
>

--
Julie Prestopnik
National Center for Atmospheric Research
Research Applications Laboratory
Phone: 303.497.8399
Email: jpresto at ucar.edu

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