[gradsusr] Scripting in GRaDS

[Rowell, Mason D.]

Jeff,

FYI, though it doesn't sound like you can take the route I said, I swapped the variables in my explanation by mistake. Use t_c (converted to K) with actual CC to get es, and dew_c with inverse cc to get actual e. 

Mason 
________________________________________
From: gradsusr-bounces at gradsusr.org [gradsusr-bounces at gradsusr.org] on behalf of Jeff Lake [admin at michiganwxsystem.com]
Sent: Monday, January 09, 2012 1:26 PM
To: GrADS Users Forum
Subject: Re: [gradsusr] Scripting in GRaDS

Haven't tried ..
the formula is from my php METAR decoder ..
the GRIB file is the RTMA..
I knew I had to use the GRIB fields,
but couldn't find any reference if the math functions where exchangeable
between php and GRaDS..

-Jeff Lake
MichiganWxSystem.com
WeatherMichigan.net
TheWeatherCenter.net
GRLevelXStuff.com


On 1/9/2012 2:10 PM, Rowell, Mason D. wrote:
> Jeff,
>
> Does this equation fail to provide you with physically relevant RH numbers, or does grads not accept the format? I'm unfamiliar with the formula. For a less precise route, I would use dew_c, convert to kelvin and use inverse CC equation to find find es, and divide e (from CC equation and t_c, converted to kelvin) by es. Use the pressure and these to instead get w/ws for more accurate result.
>
> Mason
> ________________________________________
> From: gradsusr-bounces at gradsusr.org [gradsusr-bounces at gradsusr.org] on behalf of Jeff Lake [admin at michiganwxsystem.com]
> Sent: Monday, January 09, 2012 4:34 AM
> To: Grads
> Subject: [gradsusr] Scripting in GRaDS
>
> Greetings ..
> I have searched hi and low for someone else that has been in my situation.
> I need to plot relative humidity, wind chill and heat index..
> I have the needed perimeters from the GRIB data (Temp, Dewpt,&  Wind speed)
> now if this php, I could do it all day ...
> I just can't seem to get a handle on the scripting language ..
>
> anybody want to lend a hand converting the following??
>
> rh = pow(10, (1779.75 * (dew_c - temp_c) / ((237.3 + dew_c) * (237.3 +
> temp_c)) + 2));
>
> --
> -Jeff Lake
> MichiganWxSystem.com
> WeatherMichigan.net
> TheWeatherCenter.net
> GRLevelXStuff.com
>
> _______________________________________________
> gradsusr mailing list
> gradsusr at gradsusr.org
> http://gradsusr.org/mailman/listinfo/gradsusr
>
> _______________________________________________
> gradsusr mailing list
> gradsusr at gradsusr.org
> http://gradsusr.org/mailman/listinfo/gradsusr
>
_______________________________________________
gradsusr mailing list
gradsusr at gradsusr.org
http://gradsusr.org/mailman/listinfo/gradsusr