Perception and use of uncertainty in severe weather warnings by emergency services in Germany

Abstract In the course of the WEXICOM project at the Hans-Ertel-Centre for Weather Research of the Deutscher Wetterdienst (DWD), a survey was conducted in autumn 2012 to question how weather warnings are communicated to professional end-users in the emergency community and how the warnings are converted into mitigation measures. 161 members of emergency services (e.g. fire fighters, police officers and civil servants) across Germany answered an online questionnaire. Questions included user's confidence in forecasts, their understanding of probabilistic information and their perception and use of uncertainty in forecasts and warnings. A large number of open questions were selected to identify new topics of interest, unknown problems, and research gaps in the field of communicating weather information in Germany. Results show that the emergency service personnel who participated in this survey generally have a good appreciation of the uncertainty of weather forecasts. Although no single probability threshold could be identified for organisations to start with preparatory mitigation measures, it became clear that emergency services tend to avoid forecast based on low probabilities as basis for their decisions. This paper suggests that when trying to enhance weather communication by reducing the uncertainty in forecasts, the focus should not only be on improving computer models and observation tools, but also on the communication aspect, as uncertainty also arises from linguistic origins. Here, improvements are also possible and thus uncertainty might be reducible.