[Met_help] MM5 GRIB1 format

John Halley Gotway johnhg at rap.ucar.edu
Fri May 22 09:29:01 MDT 2009

C.V. Srinivas,

Great!  I'm glad to hear it.  If any more issues or questions come up in your use of MET, feel free to write us.

met_help at ucar.edu

C.V.Srinivas wrote:
> Dear Dr.John Halley,
> I could successfully use the MM5 pressure level data converted through
> MM5toGRIB in grib1 for METV2.0
> Thanks for the help given by the MET User. Earlier when I first tried
> MM5toGRIB I missed using interpolation with the lat_lon file. So I could
> figure out the problem and the outputs are compatible to METv2.0
> with regards
> C.V.Srinivas
> John Halley Gotway wrote:
>> Hello,
>> I heard back from the other MET user who is verifying MM5 data.  He's
>> posted the code he's using to convert from MM5 sigma levels to
>> pressure levels and then create a GRIB1 file.  Please see the
>> details in his message below.
>> Based on the reason he wrote to MET-Help, it may be the case that
>> there's still some issues to be worked out in the process of writing
>> the GRIB file.  The time values may not be correct in the GRIB
>> file that's generated.
>> Hope this helps!
>> John
>> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>> Hello John,
>> Thank you for contacting me on this issue. In fact, let me give you a
>> new tar file in which there is one hour of MM5 data with all steps of
>> converting MM5 sigma levels to pressure, then into grib1 files, and then
>> running MET on the output files, including all source code, so other
>> user can go through the steps after we figure out what to do. I am also
>> including a README.1st file that I wrote to remember how I did all these
>> calculations in the future file within compare.with.MET subdirectory
>> which explains the process step by step. Most important step is
>> MM5toGRIB routine which was provided by scientists in Spain.
>> I placed the new tar file to our anonymous site for you to retrieve:
>> ftp://eos.arb.ca.gov/pub/outgoing/kgurer/MET.error.tar.bz2
>> You can get the source code for MM5toGRIB module including many other
>> utilities from here:
>> http://www.mmm.ucar.edu/mm5/mm5v3/util.html
>> (in the middle of that web page, you will see the link for MM5toGRIB).
>> You will find compiled MM5toGRIB code in my tar file, as well.
>> As I was writing this e-mail, I got your next e-mail with your
>> suggestions to debug the problem. In fact, that is exactly what I
>> thought. I tried "FULL" in spatial comparisons. And, I checked the time
>> periods. Only thing that didn't quite make sense is the order of grib1
>> file based on the help given in README file in MM5toGRIB subdirectory:
>> http://www.ecmwf.int/publications/manuals/libraries/gribex/ksec1.html
>> It seems like the order of parameters (particularly the date) written in
>> grib1 file is not correct, based on the above link. I am still trying to
>> debug it.
>> Thank you very much for helping me on this issue. I will still follow
>> your suggestions one more time to find the problem.
>> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>> C.V.Srinivas wrote:
>>> Dear John Halley,
>>> Thank you for your response. I will be happy to receive useful
>>> information regarding conversion of MM5 outputs for GRIB  format
>>> required by MET2.
>>> I came across an article from  zielonka at meteo.psu.edu,
>>> hunter at meteo.psu.edu "WRF AND MM5 REALTIME SYSTEM STATISTICAL
>>> presentation. They developed a conversion program GRIBPRS for MM5
>>> outputs for using in MET . I asked their help to provide their code for
>>> my purpose. But I did not get reply from them. Can you please write to
>>> them and get me the GRIBPRS code for using the MET2.0 in my research
>>> project?
>>> With regards
>>> C.V.Srinivas
>>> John Halley Gotway wrote:
>>>> Hello,
>>>> Unfortunately, I'm not familiar enough with MM5 data formats to
>>>> offer any
>>>> suggestions on how you might go about converting your MM5 data into a
>>>> GRIB
>>>> format for use with MET.  We primarily deal with WRF data at the
>>>> Developmental Testbed Center (DTC).
>>>> However, by coincidence, on the same day we received your MET-Help
>>>> request, we received a help request from a different user who is using
>>>> MM5
>>>> data.  He was able to convert it from sigma levels to pressure
>>>> levels and
>>>> write out GRIB verison 1 files for use with MET.  I've written him
>>>> to ask
>>>> for details on how he went about it.
>>>> I'll pass along any information or advice I hear from him to you.
>>>> Thanks,
>>>> John Halley Gotway
>>>> johnhg at ucar.edu
>>>>> Dear Sir,
>>>>> We have downloaded the METv2.0 software and installed. Our aim is
>>>>> to use
>>>>> this package for the model evaluation of MM5 model over the India
>>>>> region. However the MM5 files cannot be directly read by METv2.0 and
>>>>> needs to be converted in GRIB format. Are there tools developed for
>>>>> conversion of MM5 files to the compatible grib format required by
>>>>> METv2.0. Please advise
>>>>> thanks and regards
>>>>> C.V.Srinivas
>>>>> Scientist E
>>>>> Radiological Safety Divison
>>>>> IGCAR
>>>>> Kalpakkam , India
>>>>> _______________________________________________
>>>>> Met_help mailing list
>>>>> Met_help at mailman.ucar.edu
>>>>> http://mailman.ucar.edu/mailman/listinfo/met_help

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