The study presents the development of flood warning decision support products based on ensemble forecasts in the European Flood Alert System (EFAS). EFAS aims to extend the lead time of flood forecasts to 310 days in transnational river basins and complement Member States' activities on flood forecasting. Weather forecasts are used as input to a hydrological model and simulated discharges are evaluated for exceedances of flood thresholds. Products were developed in collaboration with users for a concise and useful visualization of probabilistic results. Forecasts of flood events observed in the Danube river basin in 2005 illustrate the analysis.