Communicating Uncertainty in Hydro-meteorological Forecasts: Mission Accomplished?
Résumé
Almost ten years ago, we published a paper where we raised the question whether effective communication of uncertainty in hydro-meteorological forecasts was an impossible mission. We wanted to understand if the multiple ways of interpreting uncertainty, as well as the multiple users and forecasting situations affecting forecast display and confidence, could hamper probabilistic forecast communication in hydrology. We looked at the main general interconnections present in a typical flood forecasting and alert chain, the challenges of extracting meaningful information from probabilistic forecasts and the way ensemble forecasts were effectively used in flood warning and decision-making. At the end of the paper, we were optimistic and tempted to bet that the "mission is not impossible, although the tasks to be executed might be difficult to accomplish." In this presentation, we discuss a follow-up question: what have we accomplished in terms of communicating probabilistic (or ensemble-based) forecasts to users in hydrological applications? We present experiments with role-play games developed to familiarize forecast producers and users with the way probabilistic predictions are used to support decisions. Approaches to foster training on the use and the value of probabilistic and/or ensemble-based forecasts and to communicate forecast quality through benchmarking skilful streamflow forecasts are also discussed.