A pre-operational hail impact assessment platform for multiple sectors in Switzerland

Hail poses a significant risk to buildings, cars, and crops, making accurate hail impact assessments critical for decision makers in the insurance industry and agricultural sector. Here, we introduce a pre-operational hail impact assessment platform for Switzerland and multiple sectors that is co-created with potential end-users in the context of the project seamless coupling of kilometer-resolution weather predictions and climate simulations with hail impact assessments for multiple sectors (scClim, https://scclim.ethz.ch/). The platform provides both hindcasts and forecasts of hail impacts. The underlying hail damage models were developed with the open-source, event-based risk modeling platform CLIMADA (https://wcr.ethz.ch/research/climada.html). The applied vulnerability curves for buildings, cars, and crops were calibrated with damage data from 2002 to 2021, which was obtained from insurance companies. To assess hail damages from the previous day, the models rely on daily radar-based estimates of the maximum expected severe hail size (MESHS) or crowd-sourced hail reports gathered through a mobile application. To forecast hail damages in the upcoming day, the models utilize the output generated by the HAILCAST hail growth model, which is integrated into the numerical weather forecasting model COSMO. The COSMO model is operated in an ensemble configuration consisting of 11 members, allowing probabilistic short-term forecasts. The platform's first prototype was tested by stakeholders during the summer of 2023 to identify the most valuable content and presentation methods. Through this ongoing collaboration, we aim to create a comprehensive platform that addresses the various needs of stakeholders and enables them to make informed decisions when facing hail risks.