Overview of Forecast Communication and Use of Ensemble Hydrometeorological Forecasts

Abstract

Over the last few decades, hydrometeorological forecasting, warning and deci- sion making has benefited greatly from advances in the natural, physical, com- puting and social sciences. A fast developing computing capability has enabled meteorologists to produce ensemble prediction systems (EPS) that quantify the uncertainty in forecasting and simulating floods, droughts, and in water manage- ment decision making. At the same time, the social sciences have helped to understand the human perceptions of risk information and how different actors communicate hazard, risk and uncertainty information. Ultimately hydrometeo- rological forecasts are used in making decisions. However, to be effective, such decisions must be communicated to the hazard response organisations and to the general public. For this, the communication must be simple and clear, it must be relevant and should come from a trusted source. This overview summarises how such communication is organised for a variety of applications in different countries. It is the effectiveness of the entire system which must be considered and assessed. As ensembles are increasingly used in increasingly longer term man- agement and policy decisions, the range of end-users and their differing require- ments can only expand and flexibility and adaptability to individual circumstances will be required from both the natural and social scientists involved.