Kabidi, Khadija (Direction de la Meteorologie Nationale, Casablanca, Maroc)
Thunderstorms occur often in Morocco especially during summer. Two major factors are behind their irruption and evolution, the presence of hot air blowing from Sahara at low levels and the incursion and the incursion of polar cold air at higher levels. The instability caused by this vertical temperature gradient is further intensified by the influence of the Atlas mountains. The present paper describes the June 1996 acse study corresponding to a severe thunderstorm which caused human and material damages as result of flash flood and thnder strikes. The description intended herein is based on synoptic charts and mesoscale informations recorded by radar, satellite, Rawinsonde and rain gauges.