Sol, Bernard (Meteo-France)
The presented work proceed from a collaboration between the National Meteorological Research Centre (Toulouse) and the south-eastern interregional Direction (Aix-en-Provence). A fine mesh (7km) and limited area (1200kmx1200km) numerical model is used to try to modelise the Mesoscale Convective Systems (MCS) we often observe in the south-east of France. This model is coupled to the global operational French model (ARPEGE).
The parametrisation of this fine mesh model has been optimised with the MCS observed on 22/09/96 at Vaison-la-Romaine. Some specific convection diagnostics to help the forecasters were studied and computed with the model outputs. Then we studied dates where MCS could be forecasted, even if no MCS where observed, and also of course dates where we observed MCS.
The results of the modelisation are presented, with comparison to observations and to outputs of the operational models. Advantages of new diagnostics are also discussed.