Hydrological forecasts are produced by forcing meteorological forecasts through a hydrological model or conceptual algorithm. In EFAS, meteorological forecasts from different numerical weather prediction systems are used for different forecasting ranges and products. Both deterministic (i.e single realisation from a single numerical weather prediction system) and ensemble (i.e. multiple realisations - also called ensemble members - from a single numerical weather prediction system) forecasts are used in EFAS, obtained from a range of providers.


•    Flash flood products are based on Radar precipitation and ensemble precipitation products
•    Medium range products are based on deterministic or ensemble forecasts
•    Seasonal and sub-seasonal products are based on extended and long range ensemble forecasts


Find more details on the different meteorological products in the Wiki under EFAS Meteorological Forecasts and under Meteorological Products Overview.