Precipitation data is vital to river forecasting. Local NWS offices must supply the RFCs with precipitation data to input into their computer models. The SERFCprecipitation gage data is blended with precipitation estimates from a network of WSR-88D radars to produce cumulative precipitation maps. This processed data is one of the main inputs into the RFC's hydrologic model.
In the past, river forecasts were made strictly on the basis of rainfall which had occurred. Today, river forecasts incorporate quantitative precipitation forecasts (QPF) into the hydrologic model, as well. This has led to more accurate river forecasts, especially in the fall and winter months, when areal rainfall tends to be more uniform.