Abstract

Using a 10-year daily data thunderstorm and dry thunder (thunder without precipitation) that spans from 1991-2000, the spatial, seasonal and inter-seasonal variations of thunderstorm frequency have been investigated with results which include the production of seasonal and inter-seasonal maps of dry thunder (thunder without precipitation) and thunderstorm frequencies. Results showed that there exists a latitudinal belt of reduced thunderstorm activity between 8 and 10°N. Also, due to absence of little dry season (LDS) over the south-eastern part of the country, they do not experience double maxima of thunderstorm activity. Hence, the weather over the country has been observed as not following the latitudinal divides. Also, the thunderstorm activities over the country are more prominent over the coast, but gradually decrease towards the inland with anomaly over Ilorin and Yola. Though, several authors have carried out series of researches on the thunderstorm activities but none have been able to look at the seasonal and inter-seasonal variations of thunderstorm frequency over Nigeria. Hence, the need to look into this aspect came as a result of the fact that thunderstorm activities is one of the most contributing systems to total precipitation in Nigeria.

Key words: Thunderstorm, seasonal, frequency, latitude, Nigeria.