Quantitative precipitation estimation or QPE is a method of approximating the amount of precipitation that has fallen at a location or across a region. Maps of the estimated amount of precipitation to have fallen over a certain area and time span are compiled using several different data sources including manual and automatic field observations and radar and satellite data. This process is undertaken every day across the United States at Weather Forecast Offices (WFOs) run by the National Weather Service (NWS).
A number of different algorithms can be used to estimate precipitation amounts from data collected by radar. Research in the fields of QPE and quantitative precipitation forecasting (QPF) is ongoing.
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Quantitative precipitation estimation Wikipedia(Text) CC BY-SA