Adaptive correction of deterministic models to produce probabilistic forecasts

Abstract. This paper considers the correction of deterministic forecasts given by a flood forecasting model. A stochastic correction based on the evolution of an adaptive, multiplicative, gain is presented. A number of models for the evolution of the gain are considered and the quality of the resulting probabilistic forecasts assessed. The techniques presented offer a computationally efficient method for providing probabilistic forecasts based on existing flood forecasting system output.