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[AWIPS #CWJ-540985]: grb2 decode question.



> This works great!   We have another question about decoding a grib2 file 
> (attached) it is a 0.25 deg fhr 35 (relative to yesterdays 06Z GFS) 
> diagnostic field GSTF covering the globe (a one-field grib2 file).    The 
> field has a Center=7, subcenter=0, discipline=0, Category=0, ID=219.
> 
> We followed the previous instructions and although are seeing it decoded in 
> the hdf5 directory, it is not showing available in the Volume Browser, but it 
> is in the Product Browser with a odd name.   Here are the details
> 
> 1. Because it didn’t exist, added to 
> /awips2/edex/data/utility/common_static/base/grib/tables/7/0/4.02.0.0.table 
> the line  219:219:Momentum Xfer Lyr Avg:m/s:GSTF
> 
> 2. Because one as specific didn’t exist, created a grid projection file 
> /awips2/edex/data/utility/common_static/base/grib/grids/FE_1440_by_721_grid_at_0.250000_degree_horizontal_res.xml
> <latLonGridCoverage>
> <name>1440721</name>
> <description>1440 by 721 grid at 0.250000 degree horizontal res</description>
> <nx>1440</nx>
> <ny>721</ny>
> <dx>0.250000</dx>
> <dy>0.250000</dy>
> <spacingUnit>degree</spacingUnit>
> <la1>-90.000000</la1>
> <lo1>0.000000</lo1>
> <la2>90.000000</la2>
> <lo2>359.750000</lo2>
> <firstGridPointCorner>LowerLeft</firstGridPointCorner>
> </latLonGridCoverage>
> 
> 3. Because it didn’t exist, added a model definition block to 
> /awips2/edex/data/utility/common_static/base/grib/models/gribModels_NCEP-7.xml
> <model>
> <name>GFS_p25</name>
> <center>7</center>
> <subcenter>0</subcenter>
> <grid>1440721</grid>
> <process>
> <id>255</id>
> </process>
> </model>
> 
> 4. Restarted ingestGrib as awips user with  sudo service edex_camel restart 
> ingestGrib  .. copied test.grb2 to /awips/data_store/ingest ... and see 
> /awips2/edex/data/hdf5/grid/GFS_p25 directory
> 
> 5. An h5ls on this file shows (h5ls 
> /awips2/edex/data/hdf5/grid/GFS_p25/SFC/GFS_p25-2022-05-25-06-FH-035.h5)
> grid::2022-05-25_06:00:00.0_(35)[2022-05-26_17:00:00.0--2023-07-17_08:00:00.0]::GFS_p25::null::null::259::GSTF9999hr::SFC::0.0::-999999.0
>  Group
> 
> 6.  Because the Volume Browser is already configured to see GSTF and apply 
> the appropriate contour and imagery the only configuration we needed to do 
> was add the model GFS_p25 to the Browser which we did by  adding the line 
> <vbSource key="GFS_p25" category="Volume" /> to 
> /awips2/edex/data/utility/cave_static/site/OAX/volumebrowser/VbSources/volume.xml
> 
> 7. The result is that the Volume Browser shows GFS_p25 as an option however 
> it is not "green" with valid data even after we select under FIELDS "Momentum 
> Xfer Layer Avg Gust" and under PLANES "SFC"
> But we did notice that in the Product Browser the product is available under 
> GRID -> GFS_p25 -> GSTF9999hr --> Ground or Water (SFC) --> 0.0 SFC and
> 
> When we select that we get the product to display - in the product stack as 
> "GFS_p25 Momentum Xfer Lyr Avg (%) 25.06 35hr Thu 17.00z 26 May 22"  which 
> other than the units (%) is correct.   We feel there is a step we've missed 
> and are unsure why in step 5 its being decoded as GSTF9999hr (for example a 
> decoded file specific to the FE domain lists out using h5ls as   
> grid::2022-05-24_00:00:00.0_(0)::GFS_FE::null::null::401::GSTF::SFC::0.0::-999999.0
>  Group)
> 


Hi Pete,

Are you creating these grid new products or receiving them from somewhere? The 
time/forecast time in the grib2 file isn't properly set.

If you run:

wgrib2 -ftime test.grb2

You get: 

1:0:CodeTable 4.11=missing,missing=-1

Which is incorrect - you should be getting something like:

1:0:35 hour fcst

If you look up grib2 code table 4.11 
(https://www.nco.ncep.noaa.gov/pmb/docs/grib2/grib2_doc/grib2_table4-11.shtml) 
- that is what specifies the type of time interval, and for your grib2 file it 
is set to missing which I believe is the issue.

Thanks,

Tiffany Meyer
AWIPS Lead Software Engineer
UCAR-Unidata

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Ticket Details
===================
Ticket ID: CWJ-540985
Department: Support AWIPS
Priority: Critical
Status: Open
===================
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