The use of MOGREPS ensemble rainfall forecasts in operational flood forecasting systems across

Abstract. Operational flood forecasting systems share a fun-damental challenge: forecast uncertainty which needs to be considered when making a flood warning decision. One way of representing this uncertainty is through employing an en-semble approach. This paper presents research funded by the Environment Agency in which ensemble rainfall fore-casts are utilised and tested for operational use. The form of ensemble rainfall forecast used is the Met Office short-range product called MOGREPS. It is tested for operational use within the Environment Agency’s National Flood Fore-casting System (NFFS) for England and Wales. Currently, the NFFS uses deterministic forecasts only. The operational configuration of the NFFS for Thames Region is extended to trial the use of the new ensemble rainfall forecasts in support of probabilistic flood forecasting. Evaluation includes con