Southern Africa's 2012–13 Violent Storms: Role of Climate Change

This study which sought to understand the phenomenal events surrounding numerous, intense and violent storms in southern Africa, was inspired by the unusually active 2012-2013 season. In addition to improving the Early warning system, the study supports the evaluation and calibration of the weather forecasting guidance NWP products and RCMs alike. The study also sought to investigate the role of Climate Change in the occurrence of these storms in addition to understanding the science behind them, the causes and possible return periods for better impact, vulnerability and adaptation studies as well as integration of Climate Risk Management practices like Weather Index Insurance and climate resilience planning into development. Preliminary analyses categorized Chivi storm as a Dry Macro-burst as the region experienced serious delayed onsets of rainfall and high temperatures, Chilonga and Mt Darwin as squall lines and nados respectively, whereas Bindura and Mberengwa cases were all Wet Macro-bursts. Density currents from nearby mountain ranges coupled with extreme temperature rises, influx of moisture into dry regions prior to these events were identified as the possible triggers which were aided by prolonged dry spells in the rain season. Rapid Climate Change is thought to have enhanced and prolonged the 2012-2013 storm activity which stretched until April which is cooler. Global warming which increases the atmospheric water vapour holding capacity, according to the Clausius-Clapeyron theory, also provides energy which fuels these violent storms. Thus as Climate Changes, the study hypothesize more intense storms, heavily impacting life, property and development.