Assessing the Performance of Convection-Permitting Regional Climate Models in Simulating the 2002 Extreme Rainfall Event Over Central Europe

Extreme rainfall events represent a substantial risk to regions across the globe, including the Central Europe. The 2002 Central European flood was a devastating natural disaster affecting countries like Germany, Austria, the Czech Republic, and Hungary. Intense rainfall, saturated soils, and overflowing rivers caused severe flooding, displacing many and leading to significant loss of life. With damages exceeding €20 billion, it remains one of Europe’s most costly flood events, heavily impacting historic cities such as Prague and Dresden (Chorynski et al., 2012).

The spatial and temporal resolution of climate models can present challenges when simulating extreme rainfall events at regional or local scales in term of both the intensity and spatial distribution of precipitation. Therefore, In this study the implementation of high-resolution RCMs with "explicit" convection has been applied which directly resolves deep convection on the model grid without relying on parameterization schemes, known as convection-permitting (CP) models (Prein et al., 2013a,b). This study evaluates the performance of RegCM5 in simulating two consecutive extreme rainfall events (6–7 and 11–13 August 2002) over Central Europe and the Czech Republic, comparing 12 km and 3 km i.e. CP-RCM simulations along with sensitivity of planetary boundary layer (PBL) scheme Holtslag and UW. The results reveal significant discrepancies in the 12km RCM simulations, particularly in Czech Republic, where they struggle to capture the rainfall patterns of both events. The model configurations with UW PBL closely follow the observed extreme rainfall patterns, demonstrating improved alignment with the events. While CP simulations improve the representation of small-scale processes, accurately capturing localized extreme events, particularly the first spell, remains challenging. These findings highlight the potential of CP-RCM simulations for extreme precipitation in terms of climate adaptation, infrastructure development, and policy planning to mitigate the potential risks