Recent years have seen remarkable improvement in the accuracy and scope of numerical weather predictions. The accuracy of global numerical weather predictions of mean-sea-level pressure and 500hPa height has improved by one-day over the last decade in the northern hemisphere, and by one day over the last three years in the southern hemisphere. Ensemble weather predictions are increasingly the prime medium-range forecasting tool in many countries. The skill of deterministic forecasts and ensemble forecasts have benefited in equal measure from developments in data availability, data assimilation methods, and model physics , numerics and resolution. New systems for forecasting severe weather are under development, based on the ensemble forecasts and on characterization of the climatology of extremes of the model used for the ensemble forecasts. Future developments in NWP will benefit from advanced satellite-sounding capabilities, effective assimilation of information on moist processes, more efficient numerics, and more accurate physical parameterizations.