" An operational flash-flood forecasting chain applied to the test cases of the EU project HYDROPTIMET"

The application of a flash-flood prediction chain, developed by CIAM, to some testcases for the Tanaro river basin in the framework of the EU project HYDROPTIME is presented here. The components of the CIMA chain are: forecast rainfall depths, a stochastic downscaling procedure and a hydrological model. Different meteorological Limited Area Models (LAMs) provide the rainfall input to the hydrological component. The flash-flood prediction chain is run both in a deterministic and in a probabilistic configuration. The sensitivity of forecasting chain performance to different LAMs providing rainfall forecasts is discussed. The result of the application shown how the probabilistic forecasting system can give, especially in the case of convective events, a valuable contribution in addressing the uncertainty at different spatial-temporal scales involved in the flash-flood forecasting problem in small and medium basin with complex orography.