Cyclogenesis is a complex process that can be dependant on the region where it happens and the processes in the background of it.
In the introduction we mentioned two kinds of orographically induced cyclogenesis in the Western Mediterranean. The first takes places
below a southwesterly ("Vorderseitentype"), the second below the north or northwesterly upperlevel flow ("Ueberstroemungstype"). At the first
type the jet streak extends from SW to NE across or north of the Alps. The cyclogenesis occurs below the right entrance region of the jet streak
corresponding to mass flux divergences in the upper and mass flux convergences in the lower layers of the atmosphere. The cyclogenesis of the
second type is dominated by a large-scale N-NW flow over Western and Central Europe to the Western Mediterranean. The corresponding jet
streak extends from N (NW) to S (SE). Cyclogenesis takes place below the left exit region of the jet streak with corresponding mass flux
divergences in the upper and convergences in lower layers.
The explanation of the process of these two types of cyclogenesis is related with theory of the cyclogenesis, one of four, which we will
mention here :
The detalied description of the theories can be found in the Mediterranean Cyclogenesis case study at the home page of the EUMeTRAIN project.
Accompanied with the cyclogenesis, the Mistral wind is important for this case study. The characteristics of the wind and the process of its development are discribed:
Mistral wind and its development