The meteorology of high‐intensity rainfall events over the west Mediterranean region

The meteorological situations in which heavy rainfall events occur over the western Mediterranean region are presented and discussed. The study of such situations has been made looking for mechanisms able to maintain convection during larger intervals than the life cycle of a single convective cell. These mechanisms have been analysed firstly from a thermodynamic standpoint, involving the determination of stability, precipitable water mass, convective available potential energy (CAPE), and bulk Richardson number (bRi). This permits definition of some features of these events and establishment of some thresholds for different variables. Secondly, resort has been made to objective analysis focused on the diagnosis of spatial and temporal distributions of quasi‐geostrophic forcing for vertical motion, convective instability, water vapour divergence/convergence at low levels and CAPE. Following this analysis compound maps were obtained, showing the zones of superimposition of the above four variables. These z...