[Met_help] [Fwd: Re: Point-Stat Tool --- Point Observation Component Issue]

[John Halley Gotway]

Tressa,

Here's the response from the NWS guy, Waylon Collins.  He would like to
pursue a reformatting tool to make use of AWIPS NetCDF METAR observations
in MET.

Should I go ahead and take a crack at this reformatting tool - as time
allows?

Thanks,
John

---------------------------- Original Message ----------------------------
Subject: Re: [Met_help] Point-Stat Tool --- Point Observation Component Issue
From:    "Waylon.Collins" <Waylon.Collins at noaa.gov>
Date:    Tue, June 23, 2009 10:12 am
To:      "John Halley Gotway" <johnhg at rap.ucar.edu>
--------------------------------------------------------------------------

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
>>
>>
>> ------------------------------------------------------------------------
>>
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-- 
Waylon Collins (Senior Forecaster)
NOAA/National Weather Service
300 Pinson Drive
Corpus Christi, TX 78406
(United States)
Telephone: (361) 289-0959