One step closer to the RainBoW: First results from the development of a new weather warning system at the German Meteorological Service

With RainBoW ("Risk-based, Application-oriented and INdividualizaBle delivery of Optimized Weather warnings), the German Meteorological Service (Deutscher Wetterdienst/DWD) launched a program to renew its weather warning system. The overarching goal of the program is to tailor weather warnings more strongly towards the needs of end users, thus enabling the recipients to make informed decisions using the information provided. Specifically, we are working on three fields of action to achieve this. First, we want to increase the forecasting horizon of weather warnings to inform users early on. For this, we are implementing a probabilistic warning trend covering up to seven days and showing the likelihood of a specific warning to occur. It should transition as seamlessly as possible into an actively distributed warning. Second, we want to improve the comprehensibility of our weather warnings. This includes strengthening the consistency of warning criteria across all warning elements. Beyond this, we intend to improve the perception by shifting the communication focus away from the meteorological description of an event towards the associated weather impacts. For the latter, besides restructuring the warning text towards a more prominent placement of recommendations for action, we also plan to establish a data-driven approach resulting in illustrative impact description to add to that text. Third, we want to individualize our weather warnings, since the warning criteria for the general public do not neccesarily meet the needs of specialized user groups (e.g. professional users). For specific weather-dependent use cases, hazard-inducing thresholds can be individual for the application at hand. To cover for this, we are developing a warning portal serving as a warning toolbox for end users, with the possibility to configure, receive and visualize warnings as needed.This contribution will give an overview over the goals of the RainBoW program at DWD, including specific updates on current developments in all three fields of action.