Abstract:A framework of dynamic user oriented interactive forecast system is proposed. The new generation forecast system contains an initial user end module for configuring the dynamic forecast target, the physical predictive, downscaling components, user end professional models, and a user oriented assessing module in association with decision making at the user end. A case study involving application of current global ensemble forecasts (TIGGE) of rainfall for hydrological users in Linyi, a region rich in rivers and reservoirs in eastern China, is conducted in order to highlight interactive involvement of the user end information during forecast process. An iteratively self improving forecast system, involving changing decision making information throughout a flood season, a changing threshold for flood leading rainfall depending on previous weather and concurrent hydrological conditions, and a dynamic user oriented assessing process of concurrent skill and uncertainty of the prediction, is built up. It is demonstrated how a forecast of flood leading rainfall leads to a better warning signal for the user with interactive involvement of the user end than without.