Hows does cumulus calculate MSLP and other variables?

[swr03crw]

I want to compare my station's pressure to that of another station I have it next to. However cumulus has logged only MSLP (presumably based on the 65 m altitude I gave it). I want to know which formula cumulus used to convert my station pressure into a mean seav level pressure (MSLP).
[It would also be of use to see formulae for other dervied/calculated variables where possible]

[beteljuice]

... I want to know which formula cumulus used to convert my station pressure into a mean seav level pressure (MSLP)

It doesn't !

It reads whatever corrected value you have in your wx base station

[steve]

For the WS2300, Cumulus just reads the corrected pressure from the station, as it does with all of the other data, except where you have told it to calculate dew point and wind chill. In most cases, I now use Steve Hatchett's routines - http://www.softwx.com/weather/uwxutils.html - but I still have a few inconsistencies where I am still using formula I found myself on the web (before I knew about Steve's code) - usually on the NOAA web site. When I get chance I intend to go through and rationalise all of the calculations to use Steve's routines.

[swr03crw]

So, to be clear, the station height box in cumulus is purely for info.
So I need to adjust my base station to a pressue of my choosing (station or, for ease of comparison with other sites, MSLP).

Thanks

[steve]

So, to be clear, the station height box in cumulus is purely for info.

It uses the supplied altitude to calculate 'altimeter pressure', as required by APRS.

So I need to adjust my base station to a pressue of my choosing (station or, for ease of comparison with other sites, MSLP).

I don't know much about La Crosse stations (beteljuice will be back soon, no doubt) but normally, yes, you have to calibrate your station to sea-level pressure by some method.

[swr03crw]

Sorry, to be so slow here. I do have a background in atmospheric physics, but I'm new to these plug-n-play style weather stations.
I am familiar with station pressure (i.e. locall-measured).
I am familiar with pressure at mean sea-level (MSLP) for comparison with weather charts and general synoptic info.
I am familiar with the hydrostatic relationship of how we expect pressure to vary with altitude (and hence I can correct for MSLP to station and vice versa).
But was is "altimeter pressure"?

Thanks,
Curtis

[steve]

It's station pressure adjusted to sea-level just using altitude, rather than MSLP which also uses temperature and humidity. QNH as opposed to QFF, in aeronautical terms, I think.