The severity of a thunderstorm can be judged in many ways. The main area of focus on this study is, however, its dynamical intensity, which can be expressed in terms of the strength and lateral dimensions of the vertical drafts. Related to these criteria are other factors, such as penetration of the updraft above the tropopause level, the strength of the surface winds, and to some extent, the maximum hail size. Surface rainfall, conversely, is not always well correlated with dynamical intensity, nor is lightning frequency. It is as such, quite probably justifiable to think of the dynamical severity in many cases as being related to the degree of steadiness of the dynamical organization. Although it has long been recognized that severe thunderstorms are favoured by strong convective instability, abundant moisture at low levels, strong wind shear usually veering considerably with height, and to some extent, a dynamical lifting mechanism, that can release instability. By analysing the main components, the vertical thermodynamic structure, the wind shear and veer and the amount and type of precipitation, forecasters are able to correctly predict the needed actions in order to mitigate severe weather events and to secure agriculture and agriculture-related industries. This paper discusses the aggravating factors of thunderstorms from a theoretical point of view with regard to agriculture, especially to the situation in the western and north western part of Romania.

thunderstorms, agriculture, severe weather events, hail, squalls

environmental engineering

Presentation: poster