This lecture covers the importance of weather forecasting in hydrometeorological risk assessment, the advancements in weather forecast accuracy over the years, the value of ensemble forecasts in predicting events like Hurricane Katrina, the key elements for better weather forecasting, and the operational use of hydrological forecasting systems. The instructor discusses the hydrological forecasting system 'Prevah' and the weather-hydro model chain, emphasizing the significance of numerical models in forecasting natural hazards. References to operational hydrological ensemble prediction systems and snowpack model calculations are also provided.