DYNAMICS OF TORNADIC THUNDERSTORMS.

Tornadic thunderstorms are the most intense and most damaging type of convective storm. Whereas ordinary convective cells grow, produce rain, and then decay over a period of 40 min to an hour, certain thunderstorms may develop into a nearly steady-state structure that persists for several hours, producing heavy rain, large hail, damaging surface winds, and tornadoes. In the article, author discusses the essential fluid processes promoting the special storm features that characterize the tornadic supercell thunderstorm. In doing so, he draws heavily from the results of three-dimensional numerical-modeling studies, in which storms can be generated under controlled conditions and which provide complete kinematic and thermodynamic data both in and around a storm. However, although these models have demonstrated good qualitative agreement with observed storms, some of the mechanisms derived from the detailed analyses of simulated storms must still be tested against future data that will be obtained from the increasingly sophisticated storm-observing systems.