Approaches for making ensemble forecasting based services more suitable to end-users needs

Most end-users are keen to exploit ensemble forecast products for decision-making, such as workflow planning, human resources management, preventive actions. An improper use of a probabilistic product can lead to taking bad decisions, which may result in consistent economic loss. Stake-holders using ensemble forecast product may be classified into two categories: the ones who integrate probabilistic products into decision-making models or leverage human expertise to provide valuable information, the ones who are not able to exploit probabilistic information and need a translation to binary forecasts. One of the current objectives of Meteo-France is to enhance the current range of products and services offered by the public institution by integrating uncertainty, reliability and probabilistic forecast information in order to meet the specific needs of each end- user. Some new approaches are presented that aims at exploring ensemble based binaries forecasts synthetising vulnerability and uncertainty to build simple and adapted decision making tools. One has been experimented to categorize wave heats risk at one day ahead. Another one has been held for vineyards protection against spring frost and developed the use of costs and losts economic balance related to the event. Both have in common that the end user impact associated to the event is the issue that is followed. The ensemble forecasting part of information that could help to determine when mitigation decision has to be taken can then be disciminated. Standardizing these approaches is also investigated in order to adress a large number of commercial and institutional sectors that are left behind the use of probabilistic forecasting today.