Hail and its impacts: An interdisciplinary research project in Switzerland

Hail represents the costliest atmospheric peril in Switzerland and many other European countries, highlighting the demand for a good understanding and actionable information about hail risk in current and future climate conditions. For this purpose, the four-year research project scClim, now in its closing stage, was initiated to bring together complementary expertise of several Swiss universities and institutions. The project’s goal is to study hail and hail impacts in a unifying framework, including (a) the improvement of radar-based hail observations, (b) the investigation of hail variability and its link to large-scale weather patterns, (c) the implementation and evaluation of high-resolution weather and climate simulations with a hail growth model, and (d) the modeling of hail impacts on different asset types such as buildings or agriculture. In the first part of this talk, we will give an overview of the project, presenting several results of the different subprojects and their connections.

In the second part, we focus on different types of impact-based hail forecasts for Switzerland. The unique data availability for Switzerland, including detailed exposure and impact data from cantonal building insurances, enabled us to implement and evaluate several impact-based hail forecasts based operational weather forecasts from MeteoSwiss with the hail growth module HAILCAST. We analyze two impact-based forecast products that have been tailored to two different user groups, private citizens who receive weather warnings, and larger institutions like federal or cantonal entities.