EUMeTrain: Case Study on Genoa Cyclone with Mistral 13-16 February 2005

Summary

In this case the development of cyclone started in the Genoa Bay triggered by the strong north upper level flow. At the beginning of cyclogenesis the flow of the cold air was tunneled through the Garone Valley between the Pyrennes and the Massif Central and through the Rhone Valley between the Massif Central and the Alps.
What makes this case special lies in the fact that with the cyclogenesis the very strong Mistral over West Mediterranean blowed alomost during the whole period.


The cyclogenesis in the Western Mediterranean was triggered by intrusion of dry, stratospheric air from north, north-west. The jet streak played the important roles in the process of cyclogenesis which can be followed through the satellite images, but also through relevant numerical parameters.
The big cyclone moved from the Genoa Bay down to south, south-east with small, similar processes (cyclogenesis) over Adriatic Sea and Central Europe. The upper level and surface low was well develop almost from the beginning of the process. The temperature advection showed the typical distribution for cyclonic circulations and the height of PV=1 indicated the intrusion of the dry, stratospheric air down to the 600 hPa.


The mechanism of Mistral was followed by vertical cross section. The VCS of wind field parallel and perpendicular on the coast of France showed origin, persistence and strenght of Mistral.