The Linear Organization of Localized Storms in the Summer Rainfall Zone of South Africa

Abstract

The spatial organization of localized showers in the summer rainfall region of South Africa has been studied by means of spatial correlation functions. A predominant linear arrangement of parallel shower belts has been identified, with an orientation between W?E and WNW?ESE. No differences were found in this respect between the driest years in the 1960's and the wettest ones in the 1950's and 1970's, but a linear trend was absent, or at least not prevalent at any fixed orientation, during the dry spell extending from the late 1940's to the early 1950's. The above linear trend has been found to persist also throughout the year, though, in general, rainfall appeared as spatially less organized during summer months than during spring and autumn.