The Extreme Precipitation Event of 11 to 16 February 1996 over South Africa

Summary

 The extreme precipitation event of 11 to 16 February 1996 was one of four significant events during the 1995/96 rainfall season over southern Africa. Extensive flooding and related damage was recorded at this time, with historical records showing one of the highest flood peaks of the past century. This extreme event is analysed using a combination of mesoscale numerical modelling and Lagrangian trajectory analysis, allowing a comprehensive three-dimensional reconstruction of the associated atmospheric structure and its evolution. The adjustments in the circulation patterns as well as the timing and contribution of different moisture source regions are clearly important in influencing the duration and intensity of this extreme rainfall event over southern Africa. The moisture that contributed to precipitation during the event, as well as to the south-western part of the country, was imported mainly from the Indian Ocean tothe east and south-east, suggesting that the equatorial Indian Ocean may not be the predominant source of moisture as previously believed.