Quantitative Precipitation Forecast (QPF)
After estimating the water loss, RainMachine takes into account the estimated QPF (Quantitative Precipitation Forecast) amount of rain, within a radius of ~1miles. QPF is an exact amount of precipitation accumulation (example 1.2 inch) for the day instead of chance of rain (expressed in percentage).
QPF is the expected amount of melted precipitation accumulated over a specified time period over a certain area.
To learn more about QPF, please refer to: more about QPF
Note: QPF becomes better as we approach the event (e.g.: the rainfall). Better results on saving water can be obtained if your program frequency is less than 3 days.
Observed Precipitation (RAIN)
The observed precipitation come from weather stations and it's usually available after 1 day. RainMachine uses observed precipitation to correct any differences in the forecast. You can supplement RainMachine weather data with reports from personal weather stations for a hyperlocal weather information as explained here.