[Met_help] Problem with MET and accumulation intervals

[Thomas Schwitalla]

John,

thanks a lot for your effort - now it works :-)

Best regards from Hohenheim
Thomas

John Halley Gotway schrieb:
> Thomas,
>
> Actually I think the problem is still in the pcp_comine.cc file.  The unexpected flag values also led to the valid time not being set in the NetCDF file header as one would expect.
>
> Please try using the attached version of pcp_combine.cc instead - and let me know how it goes.
>
> Thanks,
> John
>
> Thomas Schwitalla wrote:
>   
>> John,
>>
>> now  I have a new problem with the point_stat tool. I only have
>> "000000L_20070811_000000V" instead of leading forecast hour in the
>> filename. I assume that something has to be edited in the point_stat
>> source files...
>>
>> Thanks again for your help
>> Thomas
>>
>> John Halley Gotway schrieb:
>>     
>>> Thomas,
>>>
>>> I knew I was forgetting something :)
>>>
>>> Sorry about that.  Here they are.
>>>
>>> John
>>>
>>> Thomas Schwitalla wrote:
>>>  
>>>       
>>>> John,
>>>>
>>>> John Halley Gotway schrieb:
>>>>    
>>>>         
>>>>> Thomas,
>>>>>
>>>>> The flags in your GRIB file are set in a way that we've never
>>>>> encountered for precipitation.  Where did you get this GRIB file?
>>>>>
>>>>> I was able to reproduce the error message you're seeing.  I stepped
>>>>> through the call to PCP-Combine using a debugger and found that
>>>>> unexpected flag value in the Product Description Section (PDS) of
>>>>> the GRIB file.  I ran the file you sent and a sample GRIB file that's
>>>>> distributed with MET through the "wgrib" utility to dump out info
>>>>> about each record:
>>>>>
>>>>> File you sent...  
>>>>> 4:26640:d=07080100:APCP:kpds5=61:kpds6=1:kpds7=0:TR=0:P1=4:P2=0:TimeU=13:sfc:1hr
>>>>>
>>>>> fcst:NAve=0
>>>>> Sample GRIB file...
>>>>> 2:31408:d=05080700:APCP:kpds5=61:kpds6=1:kpds7=0:TR=4:P1=3:P2=6:TimeU=1:sfc:3-6hr
>>>>>
>>>>> acc:NAve=0
>>>>>
>>>>> Looking at these, you can see that the value for the time range
>>>>> indicator (TR) is set to 0 in yours, while it's set to 4 in the other
>>>>> file.  Now take a look at Table 5 of the GRIB spec:
>>>>> http://www.nco.ncep.noaa.gov/pmb/docs/on388/table5.html
>>>>>         
>>>>>           
>>>> thanks for opening my eyes. We used a self written program to convert
>>>> MM5 output to GRIB format. Is seems, that during the conversion
>>>> something went wrong. We successfully used this tool to convert MM5
>>>> output without parameterized convection at 2km resolution, but at 18km
>>>> parameterized convection is needed.  I assume this is a problem in our
>>>> tool :-(
>>>>    
>>>>         
>>>>> A value of 0 is used to simply define a valid time, while a value of 4
>>>>> is used to define an accumulation interval between times 1 and 2 (P1
>>>>> and P2).  MET expects that the time range indicator will be
>>>>> set as an accumulation interval for precipitation.
>>>>>
>>>>> Do you think there was an error in defining the flags for this GRIB
>>>>> file, or do you really need to be able to read this file as is in
>>>>> MET?  If you do need to read it in MET, you'll need to make two
>>>>> source code changes:
>>>>>
>>>>> (1) Replace the file METv2.0/lib/vx_met_util/read_grib.cc with the
>>>>> version that's attached.
>>>>> (2) Replace the file METv2.0/src/pcp_combine/pcp_combine.cc with the
>>>>> version that's attached.
>>>>>
>>>>> Recompile MET with a "make clean" and then rebuild MET.  Please let me
>>>>> know the origins of this file and whether we'll need to support it
>>>>> directly in MET.
>>>>>         
>>>>>           
>>>> Is it possible, that you send me the code changes as attachment now
>>>> (they were missing in your email) ;-) ?
>>>>    
>>>>         
>>>>> Hope that helps,
>>>>> John
>>>>>         
>>>>>           
>>>> Thanks for opening my eyes,
>>>> Thomas
>>>>    
>>>>         
>>>>> Thomas Schwitalla wrote:
>>>>>  
>>>>>      
>>>>>           
>>>>>> Hi John,
>>>>>>
>>>>>> currently I have a problem using pcp_combine with a grib dataset for
>>>>>> precipitation verification. I get the following error message as an
>>>>>> example:
>>>>>> "can't find grib code 61 with accumulation of XX hours in grib
>>>>>> file". I
>>>>>> attached a sample grib file, maybe you can reproduce the error.
>>>>>>
>>>>>> Best regards from Hohenheim
>>>>>> Thomas
>>>>>>
>>>>>>
>>>>>> ------------------------------------------------------------------------
>>>>>>
>>>>>>
>>>>>> _______________________________________________
>>>>>> Met_help mailing list
>>>>>> Met_help at mailman.ucar.edu
>>>>>> http://mailman.ucar.edu/mailman/listinfo/met_help
>>>>>>             
>>>>>>             
>>>>     
>>>>         
>>     


-- 
*****************************************
*Thomas Schwitalla                      *
*Institute of Physics and Meteorology   *
*University of Hohenheim                *
*Garbenstrasse 30                       *
*70599 Stuttgart                        *
*Germany                                *
*Tel.: +49 711 459 22154                *
*****************************************