Thunderstorm distribution and frequency in Australia

A recently updated Average Annual Thunder-Day Map for Australia is presented. On the basis of this map, the distribution of thunderstorms over Australia is analysed in terms of the factors required for storm development. Thunderstorms are most frequent over the northern half of the country, and generally decrease southward, with lowest frequencies in southeast Tasmania. A secondary maximum is also apparent in southeast Queensland and over central and eastern New South Wales, extending into the northeastern Victorian highlands. Thunderstorm frequency does not, in general, appear to vary in any consistent way with rainfall. There appears to be no evidence of any widespread temporal trend in thunderstorm frequency.