For my Canadian compadres, here's a quick way I converted to KPa Pressure and also graphed it using the weathershield mote... this assumes the mote's in the field transmitting inches.
Here a barometric compensation chart... http://www.engineeringtoolbox.com/barometers-elevation-compensation-d_1812.html (http://www.engineeringtoolbox.com/barometers-elevation-compensation-d_1812.html)...
Login to your raspberry pi and make a backup copy of the metrics.js file
cp /home/pi/gateway/metrics.js /home/pi/gateway/metrics.js_bak
Next nano into metrics.js
nano /home/pi/gateway/metrics.js
and modify the following line in the //WeatherShield metrics section
P : { name:'P', regexp:/P\:([\d\.]+)/i, value:'',valuation:function(value) {return (value/0.2952998748967986).toFixed(2);}, unit:'kPa', pin:1,graph:1, graphOptions:{ legendLbl:'Pressure', lines: { lineWidth:1 }} },
ctl-o to save and ctl-x to exit
reboot your raspberry pi and voila!