[gradsusr] Make a Skew-T diagram from WRF output

[Ryan Meiszberg]

Thanks for the help!

The script now works, here is a link to the skew-T image http://web.ics.purdue.edu/~rmeiszbe/testskew2.png .

Although the script now works, I'm still somewhat confused.

It seems that I can only get the diagram to plot correctly when running "grads -c filename" and not with "gradsc -c filename".  
What is the difference between grads and gradsc? With gradsc, it only plots the temperature and dewpoint lines and also appears to smooth the data.  

Ryan



----- Original Message -----
From: Jeffrey Duda <jdduda at iastate.edu>
To: GrADS Users Forum <gradsusr at gradsusr.org>
Sent: Fri, 10 Jun 2011 14:22:05 -0400 (EDT)
Subject: Re: [gradsusr] Make a Skew-T diagram from WRF output

Ryan,
I'm not sure what the ^M is at the end of each line of your script, but
check to make sure that is not affecting how it runs.  Also, note that the
program asks for snddewp in the form of dewpoint in degrees C.  Based on
your variable SPFHprs, which I'm guessing is specific humidity at pressure
levels, will not suffice.  You'll have to convert that to degrees Celsius.
If you make these changes and still get errors, note the line numbers of the
script that are mentioned in the errors and send them to me.  They will
probably tell you what is going wrong.

Jeff Duda

On Fri, Jun 10, 2011 at 1:01 PM, Ryan Meiszberg <rmeiszbe at purdue.edu> wrote:

> Hello,
>
> I'm trying to create a Skew-T diagrams using....
>
> "reinit"^M
> "open WRFPRS_2011031712_00.ctl"^M
> "set t 2"^M
> "set lat 18.275"^M
> "set lon -67.189"^M
> "set lev 1000 200"^M
> "define tt=TMPprs-273"^M
> "define qq=SPFHprs*1000"^M
> "define vel=mag(UGRDprs,VGRDprs)"^M
> "define dir=atan2(VGRDprs,UGRDprs)"^M
> *rc=plotskew(tt,qq,vel,dir)^M
> rc=plotskew(tt,qq,-1,-1)
>
> this is followed by http://moe.met.fsu.edu/~rhart/plotskew.gs
>
> The script seems to run properly for the first half and does plot
> temperature, but somewhere it is changing the Z dimensions and causes
> undefined regions for dewpoint and wind. (see output below)
>
> Data Request Warning:  Request beyond file limits
> Data Request Warning:  Request beyond file limits
> Data Request Warning:  Request beyond file limits
> Data Request Warning:  Request beyond file limits
> Data Request Warning:  Request beyond file limits
> Data Request Warning:  Request beyond file limits
> Data Request Warning:  Request beyond file limits
> Data Request Warning:  Request beyond file limits
> Data Request Warning:  Request beyond file limits
> Data Request Warning:  Request beyond file limits
> Cannot contour grid - all undefined values
> Drawing temperature sounding.
> Drawing dewpoint sounding.
> Non-numeric args to numeric operation
>  Error occurred on line 2237
>  In file plotskew2_new.gs
>  Error occurred on line 2252
>  In file plotskew2_new.gs
>  Error occurred on line 1058
>  In file plotskew2_new.gs
>  Error occurred on line 12
>  In file plotskew2_new.gs
>
>
> ga-> q dims
> Default file number is: 1
> X is fixed     Lon = -67.1913  X = 95.0002
> Y is fixed     Lat = 18.2755  Y = 138
> Z is fixed     Lev = -9.99e+33  Z = 3.33e+33
> T is fixed     Time = 13Z17MAR2011  T = 2
>
> Thanks,
>
> Ryan Meiszberg
> Senoir/Atmospheric Science
> Purdue University
>
>
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>



-- 
Jeff Duda
Iowa State University
Meteorology Graduate Student
3134 Agronomy Hall
www.meteor.iastate.edu/~jdduda