Problems decoding GRIB2 GFS Ensemble grids

[Kevin R. Tyle]

Thanks again Steve.  I can now decode the control and perturbation fields. 
However, it looks like the tables need to be further expanded so they can 
decode the "geavg" and "gespr" bulletins.

Regards,

Kevin

______________________________________________________________________
Kevin Tyle, Systems Administrator               **********************
Dept. of Earth & Atmospheric Sciences           ktyle at atmos.albany.edu
University at Albany, ES-235                    518-442-4578 (voice)
1400 Washington Avenue                          518-442-5825 (fax)
Albany, NY 12222                                **********************
______________________________________________________________________

On Tue, 10 Oct 2006, Steve Chiswell wrote:

> Kevin,
>
> The most recent version of dcgrib2 (5.9.3) will store the GRIB2 data in
> the grid file without unpacking the data block, making the GEMPAK file
> much smaller, and the
> decoding process much faster. The older GEMPAK distributions will not be
> able to read those decoded files however, since they do not know how to
> unpack the GRIB2 data block, so if you use the 5.9.3 decoder, you would
> want to upgrade the other programs as well, or recompile the dcgrib2
> program from 5.9.3 to
> use the previous packing method for the data- but you may find that
> unpacking and
> repacking the data in realtime is quite a load on the LDM pqact
> processing (otherwise, you can use nagrib2 outside of the LDM which will
> be compatible
> with the previous versions).
>
> I'll add a command line flag to the 5.9.4 dcgrib2 to allow you to select
> the storage
> method for backward compatibility.
>
> Steve Chiswell
> Unidata User Support
>
>
>
>
> On Tue, 2006-10-10 at 01:24 +0000, Kevin R. Tyle wrote:
>> Hi Steve,
>>
>> Thanks for the updated files.  I can now get it to work using the
>> GEMPAK5.9.3 version of dcgrib2 using the corrected tables.  However, even
>> with the updated tables, versions 5.9.1 and 5.7.4 of dcgrib2 still do not
>> decode.  Perhaps I shall just recompile dcgrib2 for use in these two
>> distributions (which are still in operational use here) unless you have
>> another idea.
>>
>> Thanks,
>>
>> Kevin
>>
>> ______________________________________________________________________
>> Kevin Tyle, Systems Administrator               **********************
>> Dept. of Earth & Atmospheric Sciences           ktyle at atmos.albany.edu
>> University at Albany, ES-235                    518-442-4578 (voice)
>> 1400 Washington Avenue                          518-442-5825 (fax)
>> Albany, NY 12222                                **********************
>> ______________________________________________________________________
>>
>> On Mon, 9 Oct 2006, Steve Chiswell wrote:
>>
>>> Kevin,
>>>
>>> The GEMPAK GRIB2 parameter tables use 4 numbers to define the parameter
>>> name.
>>> The 4th column is the parameter template, which allows different names
>>> to be assigned depending on the type ofaccumulation, average, ensemble
>>> etc. used.
>>> Log messages from dcgrib2 under "decode_grib2 -34" about unknown
>>> parameter
>>> mean that the decoder tables need to be updated (in particular, entries
>>> for ensemble PDTs 1 and 11 in column 4).
>>>
>>> Updated g2varswmo2.tbl and g2varsncep1.tbl tables which include the
>>> ensemble entries can be downloaded from:
>>>
>>> http://www.unidata.ucar.edu/downloads/gempak/tables/
>>>
>>> Steve Chiswell
>>> Unidata User SUpport
>>>
>>>
>>>
>>>
>>> On Mon, 2006-10-09 at 21:26 +0000, Kevin R. Tyle wrote:
>>>> I've been attempting to decode the GFS ensemble data from the "new"
>>>> CONDUIT NCEP ftp directory, as described in
>>>> http://www.unidata.ucar.edu/data/conduit/ldm_idd/ensemble_files.html#GRIB2.
>>>> However, dcgrib2 is not able to determine the GEMPAK parameter name, and
>>>> no GEMPAK grid is created.  I've attached the output from the dcgrib2 log.
>>>>
>>>> Command line used:  dcgrib2 -v 4 -d dcgrib.log YYMMHHDD_gefs_@@@.gem <
>>>> gec00.t12z.pgrb2af48
>>>>
>>>> Any ideas?
>>>>
>>>> Thanks,
>>>>
>>>> Kevin
>>>>
>>>> ______________________________________________________________________
>>>> Kevin Tyle, Systems Administrator               **********************
>>>> Dept. of Earth & Atmospheric Sciences           ktyle at atmos.albany.edu
>>>> University at Albany, ES-235                    518-442-4578 (voice)
>>>> 1400 Washington Avenue                          518-442-5825 (fax)
>>>> Albany, NY 12222                                **********************
>>>> ______________________________________________________________________
>>> --
>>> Steve Chiswell <chiz at unidata.ucar.edu>
>>> Unidata
>>>