[Met_help] Point-Stat Tool --- Point Observation Component Issue

John Halley Gotway johnhg at rap.ucar.edu
Tue Jul 14 11:26:41 MDT 2009


Waylon,

I was working on that reformatting tool this morning, and I have a question for you about it.

There are two types of values that show up in the "reportType" variable - METAR and SPECI.  Whenever I see METAR, I'm writing APDSFC in the output NetCDF file to indicate that this is a surface
observation based on NCEP conventions for message types: http://www.emc.ncep.noaa.gov/mmb/data_processing/prepbufr.doc/table_1.htm

My question is, what are the "SPECI" reportTypes?  I'm guessing it stands for "SPECIAL", but are they always at the surface?  How should they be handled?

Thanks,
John

John Halley Gotway wrote:
> Waylon,
> 
> Thanks for checking in.  I am working on it, but have been slowed by needing to get ready for a MET tutorial we're giving next week.  I'll get to work on it though and will get in touch with you when
> I have something for you.  I hope to make significant progress this week.
> 
> Thanks,
> John
> 
> Waylon.Collins at noaa.gov wrote:
>> Hello John,
>>
>> Just wondering if you made any progress developing software to convert AWIPS METAR netCDF files to Point Stat tool compatible netCDF files?
>>
>> Waylon 
>>
>> Waylon Collins (Senior Forecaster)
>> NOAA/National Weather Service
>> 300 Pinson Drive
>> Corpus Christi, TX 78406
>> (United States)
>> Telephone: (361) 289-0959    
>>
>> ----- Original Message -----
>> From: John Halley Gotway <johnhg at rap.ucar.edu>
>> Date: Thursday, June 25, 2009 1:43 pm
>> Subject: Re: [Met_help] Point-Stat Tool --- Point Observation Component Issue
>> To: "Waylon.Collins" <Waylon.Collins at noaa.gov>, met_help <met_help at ucar.edu>
>>
>>
>>> Waylon,
>>>
>>> Sounds good.  I'm busy this week with the WRF-User's Workshop.  But 
>>> I'll take a look at these files next week.
>>>
>>> Thanks,
>>> John
>>>
>>> Waylon.Collins wrote:
>>>> Hello John,
>>>>
>>>> Yes, lets pursue the strategy of developing a reformatting tool that
>>>> would read an AWIPS netCDF METAR file and write a Point-Stat tool
>>>> compatible netCDF file. I uploaded three (3) METAR files to the
>>>> collins_data subdirectory on your FTP site. Go ahead and ignore the 
>>> QC
>>>> information and simply use the actual data values. The twelve (12)
>>>> observation types you mentioned below are sufficient. Thanks for 
>>> your help.
>>>> Waylon
>>>>
>>>> John Halley Gotway wrote:
>>>>> Waylon,
>>>>>
>>>>> We do not currently have tools that will do either of the things you
>>>>> requested.  However, I took at look at the NetCDF header you sent, 
>>> and
>>>>> the format looks pretty straight-forward.  I'd be happy to
>>>>> work with you on a reformatting tool that would read a NetCDF AWIPS
>>>>> file and write a NetCDF file for input into the Point-Stat tool.  I
>>>>> don't think it'd be too difficult.  But I'd need you to send me
>>>>> a few sample files for testing and answer some questions about the
>>>>> format.
>>>>>
>>>>> If you'd like to proceed with this, please send a few sample files
>>>>> either via email or by posting them on our anonymous FTP site:
>>>>> ftp ftp.rap.ucar.edu
>>>>> username = anonymous
>>>>> password = "your email address"
>>>>> cd incoming/irap/met_help/collins_data
>>>>> put "your sample files"
>>>>> bye
>>>>>
>>>>> Looking at the NetCDF header you sent, it looks like there's a lot 
>>> of
>>>>> quality control information in the file.  The goal of this
>>>>> reformatting tool would be to extract the actual observation values
>>>>> you'd like to use in the verification.  Would it be reasonable
>>>>> initially to ignore the QC information and just use the actual data
>>>>> values?
>>>>>
>>>>> Here are the observation types I see that we would make sense to
>>>>> extract to use in verification.  Each is followed by the GRIB code 
>>> to
>>>>> which it would correspond:
>>>>> (1)  Sea Level Pressure (GRIB Code 2)
>>>>> (2)  Temperature (GRIB Code 11)
>>>>> (3)  Maximum Temperature (GRIB Code 15)
>>>>> (4)  Minimum Temperature (GRIB Code 16)
>>>>> (5)  Dewpoint (GRIB Code 17)
>>>>> (6)  Wind Direction (GRIB Code 31)
>>>>> (7)  Wind Speed (GRIB Code 32)
>>>>> (8)  Wind Gust (GRIB Code 180)
>>>>> (9)  1-hourly precip (GRIB Code 61)
>>>>> (10) 3-hourly precip (GRIB Code 61)
>>>>> (11) 6-hourly precip (GRIB Code 61)
>>>>> (12) 24-hourly precip (GRIB Code 61)
>>>>>
>>>>> Does that set of observation types look reasonable to you?  Or am I
>>>>> missing something?
>>>>>
>>>>> Thanks,
>>>>> John Halley Gotway
>>>>> johnhg at ucar.edu
>>>>>
>>>>> Waylon.Collins wrote:
>>>>>  
>>>>>> Dear Sir or Madam,
>>>>>>
>>>>>> My goal is to generate verification statistics using the 
>>> Point-Stat Tool
>>>>>> by comparing point observations with WRF-ARW gridded forecast output.
>>>>>> With respect to the Point-Stat Tool, I understand that the netCDF
>>>>>> obs_file should be created from pb2nc or ascii2nc. I do not have access
>>>>>> to data in prepbufr format, thus ascii2nc would be used. However, 
>>> I will
>>>>>> be preparing verification statistics based on 3 months of data, every
>>>>>> 3-months, time resolution of 3 hours, for 5-10 observation points.
>>>>>> Manually creating files to match the 10 column ASCII Point Observation
>>>>>> Format as input into ascii2nc is not practical. I need an efficient
>>>>>> method to create the obs_file as input into point_stat. I have 
>>> access to
>>>>>> the observations in netCDF format used by AWIPS. Attached is the output
>>>>>> from the linux command "ncdump -h" applied to one of these files. 
>>> Do you
>>>>>> have software that will either (1) convert my AWIPS netCDF files into
>>>>>> the netCDF flavor required by point_stat, or (2) input my AWIPS netCDF
>>>>>> files and output an ASCII file containing the data in the 10 column
>>>>>> ASCII Point Observation Format required by ascii2nc?
>>>>>>
>>>>>> Waylon
>>>>>>
>>>>>>
>>>>>> ------------------------------------------------------------------------
>>>>>>
>>>>>> _______________________________________________
>>>>>> Met_help mailing list
>>>>>> Met_help at mailman.ucar.edu
>>>>>>
>>>>>>     
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