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[IDV #WNP-744153]: FAO: Don Murray - MSLP Contours

Hi Tony-

Sorry for the delay in responding.  I've been playing catch up after being
away.

> Just a quick note about the attached problem with MSLP on IDV.  I am afraid
> that I was not able to do anything to solve the problem because I do not
> have any experience at programming with either Java , Jython or Python and I
> do not have the patience to start and learn either of them now.  :-(     Heh
> heh!

Unfortunately, we are in the midst of doing an IDV release and I'm
not able to put the time into writing the jython either at this point.

> I was using RIP4 to produce graphics for WRF and it was able to produce
> charts for MSLP.  I assume that the MSLP variable is included in the WRF
> output.

Actually, I'm guessing that RIP4 is calculating MSLP from the fields
in the WRF output.

> I am sorry to bother you, Don but I really would appreciate your help on
> this matter.

While you could write a formula to do this in the IDV, in general
we are recommending that people post process the WRF netCDF output
into GRIB and read in the GRIB files in the IDV.  The netCDF files
are usually on staggered grids and the IDV then has to do a lot
of interpolation to create any derived grid.  At that point, you 
have no control over the interpolation used.  

So, I would recommend that you take a look at the WRF POST software
described at:

http://wwwt.emc.ncep.noaa.gov/mmb/papers/chuang/2/wrfpost.txt

which will derive a sea level pressure grid from the available
data in the netCDF file.

Another option would be to post your request to the idvusers list
and see if anyone else has already done this.

Sorry I can't be of more help at this point.

Don Murray
> ----- Original Message -----
> From: "Unidata IDV Support" <address@hidden>
> To: <address@hidden>
> Sent: Friday, July 14, 2006 10:43 PM
> Subject: [IDV #WNP-744153]: FAO: Don Murray - MSLP Contours
> 
> 
> > Hi Tony-
> >
> >> I am having difficulty displaying MSLP contours in IDV.  My data source
> >> is WRF.
> >>
> >> The problem is that the Field Selector lists SFC PRESSURE as an available
> >> field but I want to display Mean Sea Level Pressure.
> >
> > The only way I could think to do this would be to write a Jython formula
> > that would take the surface pressure, the terrain height and the 2m
> > temperature
> > and calculate the sea level pressure from those.
> >
> >> I would appreciate your help.  Many thanks in  advance.
> >
> > I'm on my way out of town for a week, but will look at this when I
> > return if you haven't already gotten it working.
> >
> >> Yours sincerely,
> >>
> >> Tony Pigott,
> >> (Ireland).
> >
> > Don Murray
> >
> >
> > Ticket Details
> > ===================
> > Ticket ID: WNP-744153
> > Department: Support IDV
> > Priority: Normal
> > Status: Open
> >
> 
> 


Ticket Details
===================
Ticket ID: WNP-744153
Department: Support IDV
Priority: Urgent
Status: Open