[gradsusr] Plotting a NEXRAD netCDF file

Fri Sep 20 18:22:44 EDT 2013

When you create the netcdf,  make sure the resolution is very large. Im
mobile right now so i cant check my code but try something like 1000 or
even 12000.... I dont recall how big is big enough to capture the data,
but you can re-run it and experiment.

The other thing is the resolution of the grid in grads. I use a regrid
function at very high resolution. I think its something like...

Re(dbz, 0.0018)

Again the order of magnitude may be off by 10 as im not in front of my code
right now.
On Sep 20, 2013 4:32 PM, "Sytske Kimball" <skimball at southalabama.edu> wrote:

> It was level2 and I tried setting the Grid Cell Size in NOAA's WCT to a
> finer resolution than the default value. That did the trick!!
>
> Sytske
>
>
>
> Sytske (seets-kah) Kimball
> Professor of Meteorology
> Director, South Alabama Mesonet
> Dept. of Earth Sciences
> University of South Alabama
> Mobile, AL
> phone (251) 460-7031
> fax       (251) 460-7886
> email   skimball at southalabama.edu <skimball at usouthal.edu>
> web:   http://chiliweb.southalabama.edu/
>
>
>
> On Fri, Sep 20, 2013 at 3:39 PM, Jeff Duda <jeffduda319 at gmail.com> wrote:
>
>> Specifically which product did you convert?  Was it level 2 or level 3
>> data?
>>
>> Jeff Duda
>>
>>
>> On Fri, Sep 20, 2013 at 3:34 PM, Sytske Kimball <
>> skimball at southalabama.edu> wrote:
>>
>>> Jennifer,
>>>
>>> I agree. Not sure how that happened. I used NOAA's Weather and Climate
>>> Toolkit to convert the radar data to netCDF so maybe something went amiss
>>> in that process.
>>>
>>> Thanks for your help,
>>> Sytske
>>>
>>>
>>> Sytske (seets-kah) Kimball
>>> Professor of Meteorology
>>> Director, South Alabama Mesonet
>>> Dept. of Earth Sciences
>>> University of South Alabama
>>> Mobile, AL
>>> phone (251) 460-7031
>>> fax       (251) 460-7886
>>> email   skimball at southalabama.edu <skimball at usouthal.edu>
>>> web:   http://chiliweb.southalabama.edu/
>>>
>>>
>>>
>>> On Fri, Sep 20, 2013 at 3:25 PM, Jennifer Adams <jma at cola.iges.org>wrote:
>>>
>>>>
>>>> On Sep 20, 2013, at 4:17 PM, Sytske Kimball wrote:
>>>>
>>>> Jennifer,
>>>>
>>>> Thanks for your response. Replies are added in below.
>>>>
>>>>
>>>> On Fri, Sep 20, 2013 at 3:03 PM, Jennifer Adams <jma at cola.iges.org>wrote:
>>>>
>>>>>
>>>>> On Sep 20, 2013, at 3:47 PM, Andrew Friedman wrote:
>>>>>
>>>>> Hi Sytske,
>>>>>
>>>>> In your script you have 2 plot settings right after each other:
>>>>>
>>>>> 'set gxout grfill'
>>>>> 'set gxout shaded'
>>>>>
>>>>> I believe the second one overrides the first. Try commenting it out to
>>>>> see what the grfill plot looks like.
>>>>>
>>>>> That's right -- grfill will give a better view of actual grid box
>>>>> size. What does 'q ctlinfo' give you after you invoke sdfopen?
>>>>>
>>>>
>>>> The plot with 'set gxout shaded' commented out, is attached - not very
>>>> nice looking...….
>>>>
>>>> True, but that pixelated nature of the data explains why your shaded
>>>> plot looked even worse.
>>>>
>>>>  'q ctlinfo' came back with the following:
>>>>
>>>> dset KMOB_V03_20091110_035730.nc
>>>> title Nexrad 2 radar dataset  03:57:30 UTC  11/10/2009
>>>> undef -999
>>>> dtype netcdf
>>>> xdef 800 linear -127.06 0.0776505
>>>> ydef 490 linear 20.4756 0.0776505
>>>>
>>>> Which is about an 8km grid. I'm guessing the radar data is much higher
>>>> resolution than that.
>>>> --Jennifer
>>>>
>>>>
>>>>
>>>> zdef 1 linear 0 1
>>>> tdef 1 linear 03:57Z10NOV2009 1mn
>>>> vars 1
>>>> Reflectivity=>reflectivity  0  t,y,x  Nexrad 2 radar dataset
>>>> endvars
>>>>
>>>>
>>>>
>>>>>
>>>>>
>>>>> Also, you could try changing the shaded plot setting to the
>>>>> higher-resoluttion algorithm:
>>>>> 'set gxout shade2b'
>>>>>
>>>>> shade2b is not higher resolution -- it has more smaller polygons and
>>>>> takes longer to render. shade2 and shade2b should look exactly the same.
>>>>>
>>>>
>>>> 'set gxout shaded' and 'set gxout shade2' look the same.
>>>>
>>>> Sytske
>>>>
>>>>
>>>>
>>>>>
>>>>>  --Jennifer
>>>>>
>>>>>
>>>>> Andrew
>>>>>
>>>>> On Sep 20, 2013, at 12:23 PM, Sytske Kimball <
>>>>> skimball at southalabama.edu> wrote:
>>>>>
>>>>> Dear GrADS users,
>>>>>
>>>>>
>>>>> I (finally) managed to plot a NEXRAD radar reflectivity fil, in netCDF
>>>>> format, using GrADS. The plot is attached (IdaRadar-test.png) as is the
>>>>> original radar image for the same area, displayed using GRLevelII
>>>>> (RadarLevel2.png). I can't figure out why the resolution on the GrADS image
>>>>> is so much worse than on the original image. The script is also attached.
>>>>>
>>>>>
>>>>> Any help would be much appreciated.
>>>>>
>>>>>
>>>>> Thank you in advance,
>>>>>
>>>>> Sytske
>>>>>
>>>>>
>>>>> Sytske (seets-kah) Kimball
>>>>>
>>>>> Professor of Meteorology
>>>>>
>>>>>  Director, South Alabama Mesonet
>>>>>
>>>>> Dept. of Earth Sciences
>>>>>
>>>>> University of South Alabama
>>>>>
>>>>> Mobile, AL
>>>>>
>>>>> phone (251) 460-7031
>>>>>
>>>>> fax       (251) 460-7886
>>>>>
>>>>> email   skimball at southalabama.edu
>>>>>
>>>>> web:   http://chiliweb.southalabama.edu/
>>>>>
>>>>> <RadarLevel2.png><IdaRadar-test.png><StationPlot+radar2.gs
>>>>> >_______________________________________________
>>>>>
>>>>> gradsusr mailing list
>>>>>
>>>>> gradsusr at gradsusr.org
>>>>>
>>>>> http://gradsusr.org/mailman/listinfo/gradsusr
>>>>>
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> gradsusr mailing list
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>>>>>
>>>>>
>>>>>  --
>>>>> Jennifer M. Adams
>>>>> Center for Ocean-Land-Atmosphere Studies (COLA)
>>>>> 111 Research Hall, Mail Stop 2B3
>>>>> George Mason University
>>>>> 4400 University Drive
>>>>> Fairfax, VA 22030
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> gradsusr mailing list
>>>>> gradsusr at gradsusr.org
>>>>> http://gradsusr.org/mailman/listinfo/gradsusr
>>>>>
>>>>>
>>>> <IdaRadar-test2.png>_______________________________________________
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>>>>
>>>>
>>>>  --
>>>> Jennifer M. Adams
>>>> Center for Ocean-Land-Atmosphere Studies (COLA)
>>>> 111 Research Hall, Mail Stop 2B3
>>>> George Mason University
>>>> 4400 University Drive
>>>> Fairfax, VA 22030
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
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>>>>
>>>
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>>>
>>
>>
>> --
>> Jeff Duda
>> Graduate research assistant
>> University of Oklahoma School of Meteorology
>> Center for Analysis and Prediction of Storms
>>
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>>
>
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