Abstract : 2E.10
Mesoscale numerical study of Mediterranean heavy precipitating events

Raphael Bresson, Véronique Ducrocq, Didier Ricard
GAME/CNRM (Météo-France, CNRS)

The Western mountainous Mediterranean areas are prone to heavy precipitating events during the fall season. Most of them are associated with quasistationnary frontal or mesoscale convective systems and therefore are high rainfall total producers.

Several studies (Ricard 2002, Nuissier et al 2007, Ducrocq et al 2007) have focused on heavy precipitating systems over the Cévenne-Vivarais region (Southern flank of the Massif Central) on a case study basis and have highlighted different contributions of the relief either direct (Massif Central) or indirect through neighbourhood mountain ranges (Alps, Pyrenees): orographic lifting, steering flow, interaction with cold pool, ...

The study presented here aims at studying interactions between orography, low-level unstable flow and cold pool that occur during heavy precipitation events over Southern France through idealized simulations with the Meso-NH model at kilometric resolution. Sensitivity tests will be carried out by varying characteristics of the incident flow (direction, shear, instability, moisture) that impinges on the complex orography of the region.