A review of worldwide occurrence of tornadoes

Abstract The objective of the present study was to re-visit and up-date data on tornado occurrences throughout the world. This was carried out by accessing the relevant literature, analysing, re-analysing and comparing the data on tornado occurrence from various sources. The investigation was aimed at those countries/regions for which no or little information is available. In addition to the literature survey, nearly 30 Weather Monitoring Authorities in various countries throughout the world were contacted. For some countries/regions a more detailed description of tornado occurrences than that found in the literature, was obtained. Several discrepancies between various sources of information were also identified. In addition to South Africa, contour maps of the mean rate of occurrence for France, Austria and Australia were developed.