Hydrology and Earth System Sciences www.hydrol-earth-syst-sci.net 1027-5606 1607-7938 11 2 2007 10.5194/hess-11-725-2007 http://www.hydrol-earth-syst-sci.net/11/725/2007/ http://www.hydrol-earth-syst-sci.net/11/725/2007/hess-11-725-2007.html http://www.hydrol-earth-syst-sci.net/11/725/2007/hess-11-725-2007.pdf 725 737 2007-01-17 Skill and relative economic value of medium-range hydrological ensemble predictions E. Roulin emmanuel.roulin@oma.be Institut Royal Météorologique de Belgique, Brussels, Belgium A hydrological ensemble prediction system, integrating a water balance model with ensemble precipitation forecasts from the European Centre for Medium-Range Weather Forecasts (ECMWF) Ensemble Prediction System (EPS), is evaluated for two Belgian catchments using verification methods borrowed from meteorology. The skill of the probability forecast that the streamflow exceeds a given level is measured with the Brier Skill Score. 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