Simulation of thunderstorm-orography interaction in complex terrain

Windstorms constitute nowadays one of the most dangerous hazards worldwide. Local non-synoptic phenomena, in particular tornadoes and thunderstorm outflows, are often responsible for the strongest winds, and, according to IPCC projections (Masson-Delmotte et al., 2021), these episodes are expected to further worsen soon in many parts of the world because of global warming. However, given the great unpredictability of thunderstorm events, the study of their behaviour is still a challenge, especially from a numerical point of view. In this work, a study based on the explicit cloud modelling is performed to investigate the mechanisms that underlie deep convective development and intensification of a thunderstorm in the Ligurian Sea, which is one of the areas in the Mediterranean region most affected by severe convective episodes, particularly during the autumn. The performed high-resolution simulations are focused on the intense thunderstorm event and its associated downburst that hit the city of Genoa in the morning of the 14th of August 2018, during the collapse of the Morandi Bridge. We investigate the processes responsible for its development and that triggered its intensification, as well as the influence of the complex topography. One of the goals is to understand whether topography can play a role in the enhancement of the thunderstorm outflow at the ground and affect the evolution and strengthening of the whole convective system. Therefore, two simulations are performed with and without the real topography, while keeping all the other conditions equal.