Abstract
Cyclogenesis over the western Mediterranean Sea was triggered by the approach of a pre-existing upper trough over a lower frontal zone. The developing cyclone was first accompanied by heavy convective rains in northern Italy and later by heavy steady rains of non-convective character in Central Europe.
The occurrence of synoptic-dynamic anomalies is studied using re-analyses ERA-40. The location of the anomalies, their strength and extent are evaluated by the cumulative distribution function considering July–August area-related climatology of the considered variable from 1958–2002.
During cyclogenesis, significant anomalies associated with the processes that support the completion of vertical coupling between the lower frontal zone and the upper vorticity maximum are detected. Precipitation periods in the Mediterranean and Central Europe are characterised by the occurrence of the anomalies that created synoptic-scale conditions favourable for triggering and sustaining heavy rains.