[Met_help] MM5 GRIB1 format

John Halley Gotway johnhg at rap.ucar.edu
Wed May 27 08:34:30 MDT 2009

C.V. Srinivas,

I'm not exactly sure what your question is.  Are you asking:

(1) What observation data set should you use for verifying precipitation over India?
... or ...
(2) Which statistics created by the Point-Stat tool should you be looking at when verifying precipitation?

I don't really have an answer for the first question.  I'm not familiar with the Indian rain gauge network.  But I'd recommend doing what it sounds like you're already doing:
- Obtain rainfall point observations for your domain in some ASCII format from a local source.
- Use the ASCII2NC tool to convert to NetCDF for use in MET.
- Run your observations through the Point-Stat tool.

MET does not use any of the observations of precipitation within PREPBUFR files.  It only extracts pressure, specific humidity, temperature, height, and u/v components of wind from PREPBUFR files.

As for the second question, I'd like to refer you to the statistician who's leading the MET development, Tressa Fowler.  She could provide advice on interpreting the statistical output of Point-Stat.
 I've copied her on this message.

Hope that helps.


C.V.Srinivas wrote:
> Dear Dr.John Halley,
> Well I am able to derive some useful statistics for surface and upper
> air variables from MM5 model using PointStat tool, especially for winds,
> temperature, humidity, heights etc. I want to draw similar statistics
> for rainfall/ accumulated rainfall. I am using the PrepBuffr
> observations for this purpose. The Pointstat shows 0 pairs of APCP
> (model versus observations) for good number of rainfall cases of my
> study domain. I doubt whether Prepbuffr has rainfall data in it. Over
> the Indian region we do not have rainfall archives in grib formats (are
> they I doubt!). However when I have prepared ascii obeservation file
> from point rainfall data sets and converted in nc format, Pointstat
> calculated the  statistics for rainfall.
> Kindly advise me what data sets are appropriate for rainfall statistics
> using Pointstat tool for my study domain.
> Thanks and regards
> C.V.Srinivas
> John Halley Gotway wrote:
>> 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.
>> Thanks,
>> John
>> met_help at ucar.edu

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