Severe Deep Moist Convective Storms: Forecasting and Mitigation

Small-scale (2–20 km) circulations, termed ‘severe deep moist convective storms’, account for a disproportionate share of the world’s insured weather-related losses. Spatial frequency maximums of severe convective events occur in South Africa, India, Mexico, the Caucasus, and Great Plains/Prairies region of North America, where the maximum tornado frequency occurs east of the Rocky Mountains. Interest in forecasting severe deep moist convective systems, especially those that produce tornadoes, dates to 1884 when tornado alerts were first provided in the central United States. Modern thunderstorm and tornado forecasting relies on technology and theory, but in the post-World War II era interest in forecasting has also been driven by public pressure. The forecasting process begins with a diagnostic analysis, in which the forecaster considers the potential of the atmos-pheric environment to produce severe convective storms (which requires knowl-edge of the evolving kinematic and thermodynamic fields, and the character of the land surface over which the storms will pass), and the likely character of th