Melchior FRANZ wrote:
> * Martin Spott -- Tuesday 17 August 2004 15:28:
> > I just realized you already calculate the rel. humidity from
> > temperature and dewpoint. You could calculate the cloud base from these
> > two numbers and the airport elevation as well - at least our instructor
> > taught us to do so in case of of doubt.
> What? The cloud base from temperature and dewpoint?

Yes, the dew point represents the temperature, when humidity
precipitates. In wet adiabatic conditions, which are likely to
predominate, temperature decreases 1 degree Celsius per 100 m altitude.
Now you can calculate the height above GND of your cloud base if you
know elevation and the spread (temperature at GND - dewpoint).

> And then:
>   $ ./metar -e `zcat $FG_ROOT/Airports/default.apt.gz|awk '/ LOWW /{print $5}'` -c 

I agree, this is a bit complicated for the average user  ;-))
Maybe it would make more sense to intregrate this logic into FlightGear
in order to make the weather model more realistic,

 Unix _IS_ user friendly - it's just selective about who its friends are !

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