[ncl-talk] Trying to decode a grib file with limited success

[Dennis Shea]

NCL is correctly unpacking the values.

The issue is that the variable's long_name and units are not in the table
lookup used by NCL. In a sense, GRIB file contents are a bit of a 'moving
target.' The tables must be updated continually. NCL is no longer
performing that task.

Example:

The variable id is 233

      float VAR_0_1_233_P0_L1_GLC0 ( ygrid_0, xgrid_0 )
         center :       US National Weather Service - NCEP (WMC)
         production_status :    Operational products
         long_name :    unknown variable name                      <=====
         units :
 unknown                                                    <=====
         _FillValue :   9999
         coordinates :  gridlat_0 gridlon_0
         grid_type :    Lambert Conformal can be secant or tangent, conical
or bipolar
         parameter_discipline_and_category :    Meteorological products,
Moisture
         parameter_template_discipline_category_number :        ( 0, 0, 1,
233 )
         level_type :   Ground or water surface
         level :         0
         forecast_time :        5
         forecast_time_units :  hours
         initial_time : 03/20/2022 (12:00)

warning: Entry (233) not found in code table file
/Users/shea/devel/ncl/lib/ncarg/grib2_codetables/ncep/4/4.2.0.1.table

You will have to look up grib2_codetables/ncep/4/4.2   or some such thing.
Then, manually enter the appropriate information.

    X = f->VAR_0_1_233_P0_L1_GLC0
    X at long_name = "..."
    X at units           = "..."

Good luck

On Sun, Mar 20, 2022 at 12:08 PM Andrew Kren - NOAA Federal via ncl-talk <
ncl-talk at mailman.ucar.edu> wrote:

> Hi there,
>
> I am trying to decode an NBM blend of models grib file but having
> trouble determining what the variables are for certain unknown ones.
>
> When I do an ncl_filedump, I get several listings from the file that are
> "unknown variable name". I'm trying to determine the prob snow, sleet, ice,
> rain variables but looking at both the ncdump info and the index files, as
> well as NOAA VLab is still confusing. The file I am trying to read is
> located at this link:
>
>
> https://nomads.ncep.noaa.gov/pub/data/nccf/com/blend/prod/blend.20220320/12/core/blend.t12z.core.f005.co.grib2
>
> Any help is much appreciated!
>
> --
>
> Andrew Kren
> Meteorologist
> NOAA's National Weather Service
> Raleigh Forecast Office
> 1005 Capability Drive, Suite 300
> Raleigh, North Carolina 27606
> voice: 919-326-1035
> mailto: andrew.kren at noaa.govhttp://www.weather.gov/rah
>
>
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