Despite substantial advances in both forecasting capability and emergency preparedness, recent years have seen a large number of natural disasters that have cost many lives, displaced large numbers of people, and caused widespread damage to property and infrastructure. Many of these disasters result from severe weather interacting with society. At the same time, less severe weather events place a continuing strain on society through more frequent impacts of smaller magnitude. This is especially evident in less developed countries with more fragile economies and infrastructure. In addition, weather forecasts are becoming increasingly important for economic applications (e.g. forecasting energy supply and demand) and for protecting the environment. In all these areas users of weather information expect more sophisticated guidance than was the case ten years ago.
The THORPEX programme delivered major advances in the science of weather forecasting thus providing the knowledge basis for improving early warnings for many High Impact Weather events for one day to two weeks ahead. At the same time, new capabilities in short range forecasting arising from the use of new observations and convective scale Numerical Prediction Models and Ensemble Prediction Systems have made it possible to provide warnings of weather related hazards, directly, up to one or two days ahead. Together with advances in coupling prediction models and better understanding by social scientists of the challenges to achieving effective use of forecasts and warnings, these advances offer the basis for a dramatic increase in the resilience of communities and countries to the threat of hazardous weather and its impacts. The time is ripe to capitalize on these advances.