Abstract: The concepts and technologies disclosed herein are directed towards a predictive hydrological impact diagnosis system. According to one aspect disclosed herein, the system can obtain weather data associated with an area. The weather data can include an interval rainfall forecast and a total accumulated rainfall forecast for the area. The system can execute a flood index algorithm using the interval rainfall forecast and the total accumulated rainfall forecast. In response to executing the flood index algorithm, the system can obtain an output of the flood index algorithm. The output can include flood index data for the area. The system can plot the flood index data on a graph to show a forecasted rainfall intensity over a time. The system can determine hydrological potential energy data for the area. This data is representative of a cumulative area of the graph that is above a predetermined threshold value.