Development of an early indicator index for tornadic storms in the Euro-Mediterranean region

Abstract

Tornadoes are the most violent and destructive of all the severe weather phenomena that localized convective storms produce. Supercells in particular and severe convective storms in principle are among the primarily responsible section for the global losses in both lives and properties caused by tornadoes. A tornado is a narrow and violently rotating column of air, in contact with the ground, either pendant from a cumuliform cloud or underneath a cumuliform cloud, and often (but not always) visible as a funnel cloud around wall cloud. For a vortex to be classified as a tornado, it must be in contact with both the ground (or sea surface) and the cloud base. The movement, type, strength, and influence of fronts on clouds and precipitation must be accounted for in weather forecasts. Fronts can produce severe, structured convective storms, depending on the air's static stability in the presence of a frontal system. When the temperature and humidity gradients across the front become stronger, leading to the development of a more distinct and well-defined frontogenesis. It is revealed that as one of the main phenomena in severe weather in meteorology, thunderstorms are the most common source of hazardous weather at local scales including large hail, strong winds, and tornadoes. Known as mesoscale convective systems (MCS), these thunderstorm clusters are smaller than low-pressure systems with cold and warm fronts, but larger in scale than any single thunderstorm. Supercells or bow echoes may be embedded within MCSs and also coexist with multicells. Strong tornadoes are mostly produced by these persistent severe thunderstorms which known as mesocyclone supercell storms or bow-echo storms in terms of storm type in radar echo. In order to understand how a tornado occurs, it is necessary to examine the dynamics of mid-latitude front systems and mesoscale convective storm mechanisms (thunderstorms) very well. The middle latitudes between about 30° and 50° North or South, climatologically provide the most favorable environment for tornado-genesis and sometimes in land-falling tropical cyclones, nevertheless, common in US and Canada. Likewise, Europe is also intriguing continent for occurrence of severe convective storms and tornadoes.