20000406: storm relative winds

Mohan,

The ETA212 grids actually have a the U and V storm motion:
   64     000406/1200F000                       6000  0      HGHT VSTRM       
   65     000406/1200F000                       6000  0      HGHT USTRM
To create a vector from these 2 components,
VECN(USTRM,VSTRM)
Click on the "Vector" and "Layer" radio buttons in the Garp model selection
and chose the 6000:0 lyer from the Height coordinate pop-up.

If you want to specify your own storm motion vector using your own components,
you can just enter their U & V magnitudes like:
VECN(5,-5)

One more way would be to use the VLAV(OBS) function to create an avarage
wind over a layer as a way to specify a storm motion.

Steve Chiswell
Unidata User Support



On Thu, 6 Apr 2000, Mohan Ramamurthy wrote:

> Hi Chiz,
> 
> How do I plot storm relative winds in GARP?  I see that GEMPAK has  a VSUB 
> function I could use and subtract out storm motion, but how do I specify 
> storm motion as a vector (which would be second argument for VSUB)?  Thanks.
> 
> Mohan
> 
> 
> ----------------------------------------------------------------------------
> Dr. Mohan Ramamurthy                                  Email: address@hidden
> Associate Professor                                   Ph:  (217) 333-8650
> Department of Atmospheric Sciences                    Fax: (217) 244-4393
> University of Illinois at Urbana-Champaign
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> Urbana, IL 61801-3070
>