Mesoscale atmospheric vortex generation over the Adriatic Sea

Circumstances under which the Adriatic mesoscale vortex was generated at the end of March, 1995 is investigated. Assuming that a mesoscale vortex can be isolated from the synoptic environment, the scale separation technique is employed. This provides the mesoscale orographic disturbances with characteristic quasi-antisymmetric dipolar structure across the Dinaric Alps. The mesoscale wind field contains a pronounced ageostrophic component with small-scale vortices of short duration and clearly marked convergence zones. Hence, the cyclonic vortex was generated over the middle Adriatic in a macroscale wind field as defined here, in which the smaller scale instabilities, as noise, are filtered out during the procedure. A very persistent mesoscale anticyclonic vortex is found in Pannonian Plain following the northerly flow around the eastern flank of Alps. This flow is responsible for the Adriatic occurrence, but it also contributes to the Adriatic circulation, in which jugo wind in the southern and bora in the northern Adriatic lead to the vortex generation examined.