Re: Data Extraction from NWP models

I very much doubt people would have a ready made
tool to do what you want ... in NCL or any other
language.

Could NCL do what you want? Yes.

GRIB: It can read any GRIB file.

INTERPOLATION: depending upon if the grid is
regular or curvilinear it could invoke the appropriate
interpolation code.

OUTPUT: Yes it could output the interpolated information.

COMMAND LINE: Yes ... using NCL's Command Line
Arguments, it could be made to run from the command line
or be invoked from, say, PERL.

THERMODYNAMIC CALCULATIONS: NCL has functions
but some of the requirements you request are
"custom". Specific code would have to be written
in, say, NCL do do what you want.

So all can be done .... but I doubt anyone
will write this custom code.

Good luck

Waylon.Collins_at_noaa.gov wrote:
> Dear List,
>
>
>
> My first goal is to locate command-line software (no GUIs) that will
> allow me to (1) input GRIB files containing archived WRF-NMM, Eta, and
> RUC numerical weather prediction (NWP) model forecast output, and
> latitude/longitude values for a particular point, then (2) output the
> interpolated values for selected variables at that latitude/longitude
> point, in a manner that is faster than my current method. My current
> method is to use Arthur Taylor's degrib program
> (http://www.weather.gov/mdl/NDFD_GRIB2Decoder). In particular, I have
> run degrib from within a Perl script which extracts selected output from
> Eta/WRF-NMM GRIB files. However, my data set is several years long and
> it takes 1 week to process 1 year of data -- too slow! My programming
> experience is limited to shell scripting. I have some experience with
> NCL, but not with extracting data from numerical models. Has anyone
> written an NCL script to perform the foregoing t asks?
>
>
>
> My second goal is to calculate certain thermodynamic parameters (at
> specific latitude/longitude points) not available in the aforementioned
> GRIB files. The parameters are (1) Equilibrium Level (EL) height, (2) EL
> temperature, and (3) CAPE in the -10C to -20C layer. To clarify, the
> source data are Eta, WRF-NMM, and RUC GRIB files containing NWP forecast
> output, not "sounding" data. Does anyone have an NCL script to perform
> these tasks?
>
>
>
> Dennis Shea provided helpful comments to me on 17 August 2005 relating
> to the inability to use NCL's uv2dv_cfd function with the Eta and WRF
> (NMM/ARW??) NWP models. Hopefully, I can use NCL to simply extract
> interpolated values (from selected variables) at specific
> latitude/longitude points from NWP model data written to GRIB files. On
> 12 April 2007, Mary Haley mentioned Fortran code to perform some of the
> thermodynamic parameters. However, I need to extract EL height and
> temperature, and CAPE for specific layers, from NWP output, not
> a "sounding".
>
>
>
> Sincerely,
>
> Waylon
>
>
>
> Waylon Collins (Senior Forecaster)
> NOAA/National Weather Service
> 300 Pinson Drive
> Corpus Christi, TX 78406
> (United States)
> Telephone: (361) 289-0959
>
>
> ------------------------------------------------------------------------
>
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Received on Wed Aug 08 2007 - 09:24:45 MDT