Abstract : 2E.11
Analysis of a Mediterranean “hurricane” over south-eastern Italy

Agata Moscatello, Mario Marcello Miglietta, Richard Rotunno
agata@le.isac.cnr.it
ISAC-CNR

The presence of a subsynoptic-scale vortex, formed over the Mediterranean Sea, has been documented in south-eastern Italy on 26 September 2006. Radar maps, Meteosat Second Generation satellite images and surface stations reveal that the vortex had features similar to those of tropical cyclones. The Weather Research and Forecasting Model (WRF) has been setup in a configuration including two nested grids. Model results show that the model is able to realistically simulate the origin and evolution of the system, although a strong sensitivity to the specification of the initial conditions is apparent. An analysis of the mechanisms responsible for the development and the maintenance of the cyclone has also been performed. Simulations show the topographic origin of the vortex, which was initiated on the lee side of the Atlas mountains. Subsequent to this topographically induced initiation, during the movement of the cyclone over the Mediterranean Sea, the sea surface fluxes play a dominant role in the maintenance of the system.