Risk Assessment for Hail Damages to Buildings and Cars in Switzerland: Current Risk and Future Projections

Hail is a severe meteorological hazard that can cause significant damage to both buildings and cars. Here, we present the first-ever open-source risk model for hail damages, provided within the CLIMADA framework. The availability of high-resolution radar-based hail intensity measures and detailed damage and exposure data from local insurance companies in Switzerland allows for a spatially explicit calibration of vulnerability functions for buildings and cars. The model is able to provide climatological evaluations of hail risk and real-time hail damage estimates based on any user-provided exposure data. Furthermore, combined with crowd-sourced hail reports, the detailed damage data allows for an evaluation and uncertainty quantification of different radar-based hail intensity measures. Results highlight the limitation of radar-based state-of-the-art hail size estimates, such as Maximum Expected Severe Hail Size (MESHS), for accurate risk assessments of hail damages. In a second step, the model will be expanded to use high-resolution convection resolving simulations with the hail growth module HAILCAST as hazard variable. This enables the assessment of hail risk under climate change, when driven by 2-km nested climate simulations following a pseudo global warming approach. This submission is part of the scClim project (https://scclim.ethz.ch/), which seamlessly couples kilometer-resolution weather predictions and climate simulations with hail impact assessments for multiple sectors.