Crespi, Massimo (Veneto Region, Agrometeorological Department, Experimental Centre of Hydrology and Meteorology)
Monai, Marco (same affiliation)
Zalazar, Elizabeth (same affiliation)
Veneto region climate is greatly influenced by the complex orography that characterises Northern Italy. Alpine mountains modify one of the most important weather parameters: rainfall, which intensity increases when approaching them.
Also the near Adriatic sea leads to precipitation. Besides originating advection fogs during cold seasons, relative hot moist air masses coming from the sea, during autumn, also produce stratified clouds with wide spread precipitation in the inner areas and sometimes stormy weather along the coast. These advected air masses develop thunderstorms also during spring and summertimes when a temperature decrease takes place at medium levels.
Po Valley summertime storms are also often associated with severe phenomena such as hail, strong winds, squall lines and sometimes even tornadoes.
In the majority of cases this events are linked with synoptic dynamical forcing, nevertheless in many cases stormy weather takes place because of deep convection.
Modern meteorology uses radar systems to monitor rain. With this new system it is possible to follow precipitation, knowing its position, intensity and, with doppler techniques, also its movement.
These possibilities become very useful specially when facing isolated thunderstorms, like the ones developed with thermal instability.
Several severe weather events that took place during the period 88-92 had been analysed.
To study these phenomena different kinds of information collected also with remote sensing techniques (specially weather radar) were used.
In more detail the analysis was made considering:
*weather charts (surface, standard levels, jet streams, etc) *ground stations data (temperature, sun radiation, precipitation, wind speed and direction, pressure, etc) *radio soundings *weather radar images *satellite images
The integrated study of these hazardous events allowed to improve the knowledge of these phenomena, so common on Po Valley, with interesting possibilities of operative applications in forecasting field.