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[IDV #KZL-643401]: Dew Point Depression in IDV

Dear Nicholas,

Short answer/workaround: In the Displays tab, convert to kelvin (Edit --> 
Change Display Unit), and change the color table and contour intervals.

Long Answer: Temperature scales like Fahrenheit, and Celsius are difficult 
because their zero point is not at absolute zero. The problem is that the 
temperature and dew point are converted to kelvin before the calculation. After 
the difference calculation, you have a delta expressed in kelvin which is the 
same as the delta in Celsius. Unfortunately, that final delta is converted to 
Celsius (as if it were not a delta) resulting in nonsensical values.

Best Wishes,

Unidata IDV Support

> Full Name: Nicholas Rothfuss
> Email Address: address@hidden
> Organization: Central Michigan University
> Package Version: 3.0u2 build date:2012-02-10 17:21 UTC
> Operating System: Linux
> Hardware: Java: home: /usr/local/IDV_3.0u2/jre version: 1.6.0_20 j3d:1.5.2 
> fcs (build4)
> Description of problem: I am getting non-sensical values for dew point 
> depression (on the order of -250 degrees Celsius at 850 hPa) with both 
> current GFS and NAM data (sourced from the Mother Lode catalog).  This is the 
> case for both the first time and all additional times (out three days, in my 
> situation) rendered.
> 
> 


Ticket Details
===================
Ticket ID: KZL-643401
Department: Support IDV
Priority: Normal
Status: Closed