CROSCEA
Cross-Scale Processes of extreme convective events in the European Alps
Convective events, which include extreme precipitation, wind, lightning and hail, consistently account for a significant proportion of insured natural hazard losses and particularly affect agriculture, vehicles and buildings. In recent years, record-breaking hailstorms (up to 19 cm in Europe), significant damage (e.g. in Switzerland in 2021) and long-lasting, intense convective storms have been reported. The rise in temperature caused by global warming increases the saturation vapor pressure of the air and thus intensifies convective processes through moisture supply and increased latent heat release. Many of the most intense convective events in Europe occur around the Alps, where the large-scale atmospheric flow is significantly influenced by the complex topography of the mountain ridges and valleys and interacts with regional to local processes. Recent climatologies of hail and lightning indicate pronounced hotspots of convective activity around the Alps. However, a comprehensive analysis of these hotspots, their spatio-temporal variability and the underlying processes has not yet been conducted across several Alpine countries and convective hazards.
Objective and Methods
The objective of CROSCEA is the systematic classification and characterization of convective hotspots in the Alpine region. Subsequently, the regional to local processes that lead to increased convection will be analyzed in more detail using high-resolution observation and model data. CROSCEA is associated with the Europe-wide TIM field campaign (Thunderstorm Intensification from Mountains to Plains) of the European Severe Storms Laboratory (ESSL) and is committed to contributing to the overall objectives of TIM with its results.
