The project “Assessing the Impact of Hailstorms in a future Climate” (HailClim) as a sub-project of the joint project ClimXtreme (Module C) aims to derive past and future trends for hail of different intensity classes and to determine the effects of climate change on hail damage. Since hail causes massive damage to buildings, vehicles and agriculture, information on the effects of climate change on hail frequency and intensity and the associated damage is of great interest to various user groups. As a very small-scale phenomenon with little direct observation data, knowledge of the local hail hazard and its future development is very limited.

In HailClim, suitable combinations of thermodynamic and dynamic parameters (proxies) are first sought that best describe past hailstorms of different intensity classes. An object-oriented approach based on radar-detected cell attributes for Germany will be developed and applied to determine possible causes for trends in the data sets relevant for hail. Based on the improved relationships found between objects and environmental conditions, it will then be estimated how the frequency of hail of different intensity classes will change for different climate scenarios (e.g. +1.5, +2, +3 K). This information is transferred to an existing hail risk model, which still needs to be extended to the whole of Germany in order to be able to estimate changes in hail damage and hail risk in the future.