Thunderstorm Intensification from Mountains to Plains: The TIM Campaign

Observational data of thunderstorm hazards, such as hail reports in the European Severe Weather Database, suggest that severe convective storms are especially frequent over the surrounding slopes of mountain ranges. The same geographic regions are also projected to experience the strongest increases in severe weather occurrence as a result of global warming. Given the potential high impact of intensifying severe convection in these densely populated parts of Europe (and other regions of the world), it is critical to better understand where and why these storms become more severe. While a number of field campaigns has investigated either terrain effects on the atmospheric boundary layer or severe storm dynamics away from terrain, their topical overlap, severe convection dynamics near terrain, is less researched.For these reasons, ESSL is currently coordinating efforts to plan an international field campaign on severe convective storms surrounding the Alps and lower mountain ranges in central Europe from the Pyrenees to the West to the Tatras mountains to the East. A network of over 20 partner institutions across these countries has already been engaged. The research focus is on high-resolution data collection of the pre-convective environment and within individual severe storms. However, the field campaign will also provide wider opportunities to validate recent innovations in forecasting, nowcasting, and measurements, such as new instruments on the Meteosat Third Generation satellite, numerical model parametrizations of terrain-related processes, drone-based surveys and profiling, and polarimetric radar algorithms. This presentation will give a short review of the scientific literature on the topic of severe convective storms near complex terrain and summarize the most important research questions. Based on that, the current plans for the TIM field campaign are presented to invite collaborations from the EMS community.