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[McIDAS #VPF-945811]: Isobars based on PRE of METAR + PSL at seas

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  • Subject: [McIDAS #VPF-945811]: Isobars based on PRE of METAR + PSL at seas
  • Date: Thu, 14 Dec 2006 10:27:26 -0700
Hi Kwan,

re:
> Currently, if I want to draw isobars based on both the
> land and sea stations, I do the following McIDAS command.
> 
> SFCCON PMSL X 18 2006346 LSIZE=12 CIN=4 COL=3 LLI=.75 .75
> DAT=RTPTSRC/SFCHOURLY RTPTSRC/SHIPBUOY RTPTSRC/SYNOPTIC
> 
> I know that there are two types of pressure reported in
> land stations (METAR).  They are PRE (pressure reduced to
> mean sea level) and PSL (altimeter settings).  Only
> sea-level pressure is reported by ships and buoys.
> 
> When I execute the above command, I see that SFCCON uses
> PRE over land and PSL over seas.  Is there a way to tell
> SFCCON to use PRE over land instead of PSL when contouring
> PMSL using multiple surface datasets?

Yes.  The online help for SFCCON says this about selecting
the pressure to plot:

   In the PTYPE keyword, specify either PMSL or SLP for sea-level
   pressure, and ALT, ALTM or ALTIM for altimeter setting. The keyword is
   valid only with the calculated options that contain station pressure
   in their equations (PSTN, MIX, THA and THAE). Altimeter setting is the
   default because it's correct to use it (rather than sea-level pressure)
   when computing station pressure for use in the equations.

I am not exactly sure what this will do for the SYNOPTIC and SHIPBUOY
plotting, however.


Cheers,

Tom
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Ticket Details
===================
Ticket ID: VPF-945811
Department: Support McIDAS
Priority: Normal
Status: Closed