Re: winds from WRF not matching RAOB

Hi Steve,

I recently had to produce Skew-T plots of WRF output and RAOB data overlaid together in NCL, similar to what you are trying to do. I've attached a template of the NCL script I used as well as a RAOB file that the script read in. Please let me know if this helps you.

Regards,

Elliot Tardif.

Elliot Tardif, Meteorologist I
NC DENR, Division of Air Quality
Planning Section, Attainment Planning Branch
1641 Mail Service Center
Raleigh, NC 27699-1641
Phone: 919-715-9773
Fax : 919-715-7476
Email: Elliot.Tardif@ncdenr.gov<mailto:Nick.Witcraft@ncdenr.gov>
Web : http://www.ncair.org<http://www.ncair.org/>

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From: ncl-talk-bounces@ucar.edu [mailto:ncl-talk-bounces@ucar.edu] On Behalf Of steve kirby
Sent: Tuesday, September 20, 2011 6:00 PM
To: ncl-talk@ucar.edu
Subject: winds from WRF not matching RAOB

Sorry - forgot to note, in the attached figure, WRF winds are in orange; RAOB winds are in black

--Steve

----- Forwarded Message -----
From: steve kirby <thin_runner@yahoo.com>
To: "ncl-talk@ucar.edu" <ncl-talk@ucar.edu>
Sent: Tuesday, September 20, 2011 3:54 PM
Subject: winds from WRF not matching RAOB
Hi,

I'm doing some plots of RAOB's vs WRF and the WRF-extracted winds aren't matching the RAOB. Here's the WRF portion --

=============================================================================================
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/skewt_func.ncl"
load "$NCARG_ROOT/lib/ncarg/nclscripts/wrf/WRFUserARW.ncl"

...

a=addfile("./wrfout_d02_2010-07-16_20_00_00.nc","r");

;get the variables
 wrftc=wrf_user_getvar(a,"tc",0)
 wrftd=wrf_user_getvar(a,"td",0)
 wrfp=wrf_user_getvar(a,"pressure",0)
 wrfz=wrf_user_getvar(a,"z",0)
 uvm=wrf_user_getvar(a,"uvmet",0)

;extract u and v from uvm array and convert to knots
 u=uvm(0,:,:,:)*1.94386
 v=uvm(1,:,:,:)*1.94386

;;;;
 ; get ij point in model domain for location of interest
 ; loc(1) is touth-north (y) and loc(0) is west-east (x)
 ; ensure this point is in the domain, as we are not checking
 ; we are interested in NCL array pointers, so subtract 1
  loc=wrf_user_ll_to_ij(a,-106.93,32.28,True) ; it should read (a, lon,lat,True) is that right?
  locX=loc(0)-1
 locY=loc(1)-1

dataOpts@colTemperature<mailto:dataOpts@colTemperature> = "red"
 dataOpts@colDewPt<mailto:dataOpts@colDewPt> = "magenta"
 ;new location for winds (default is 45)
 dataOpts@xpWind<mailto:dataOpts@xpWind> = 40.
 dataOpts@colWindP<mailto:dataOpts@colWindP> = "orange"

skewT_data = skewT_PlotData (wks,skewt_bkgd,wrfp(:,locY,locX),\
                                            wrftc(:,locY,locX),\
                                            wrftd(:,locY,locX),\
                                            wrfz(:,locY,locX),\
                                            u(:,locY,locX),\
                                            v(:,locY,locX),\
                                            dataOpts)

draw(skewT_data)
=====================================================================================================

QUESTION - Do I have it right, that in the wrf_user_ll_to_ij( ) call that I use longitude, latitude (in that order) to locate the point of interest?

I have done a couple of other plots of WRF winds vs. RAOB and the winds are not matching up with those either, so I was wondering if I had something wrong in code.

Thanks,
Steve

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