Northwestern Mediterranean region is often affected by heavy precipitating events, mostly during autumn. The present study aims at better understanding the relationship between mesoscale meteorological environment characteristics and location and intensity of heavy precipitating systems, by investigating mechanisms responsible for deep convec- tion triggering and maintain. First, idealised numerical simulations of quasi-stationary convective systems over the Cevenol region were analysed to highlight the dominent mechanisms. Sensitivity experi- ments varying humidity and wind speed of the marine inflow help to establish relation- ships between environment characteristics, dominent triggering mechanisms and precipi- tating system location. The results of this idealised study were confronted to the flood case of Var, June 15th, 2010. A quite large set of numerical simulations were performed to reproduce at best the heavy precipitation event. Then, the best simulations were used to understand the mechanisms leading to the quasi-stationary precipitating system observed over the Var region.
