In a changing climate, with increasing temperatures and moisture, the extratropical circulation will likely change, and so will the dynamics of North Atlantic windstorms. Extratropical storms may take different paths than in the past, and show modified characteristics such as their frequency, intensity, lifetime, or extent. However, these changes of storm characteristics and impacts, especially on the regional scale, still exhibit substantial uncertainties due to low confidence in the underlying changes of the circulation and storm tracks in a changing climate - partly because the interannual variability is larger than climate change related trends but also because previous analyses are based coarse resolution simulations and/or single model studies.

This project “Sturmklima Hessen”, funded by HLNUG (Hessisches Landesamt für Naturschutz, Umwelt und Geologie), aims to address these issues.

It aims to estimate the spread of possible developments regarding the storm risk and its impacts for the federal state of Hessen, Germany in a changing climate. A multitude of global and regional climate simulations is evaluated, including spatially and temporally higher resolved models preferably in large ensembles, to draw robust conclusions on expected changes using different warming scenarios. In cooperation with the GDV (Gesamtverband der Deutschen Versicherungswirtschaft) the storm induced loss on residential buildings will be related to the wind speed of model and observation based data using deterministic and probabilistic statistical models. The impact of the resolution of the model on the representation of the storm climate is explored and particularly ruinous episodes as well as categorized storm events are downscaled to estimate the range of losses. Seasonal and decadal predictions are considered as well as high resolved (regional) climate experiments.