Analysis of the Percentage Contribution of Squall Lines and Thunderstorms to Annual Rainfall Amount Over the Middle Belt Region of Nigeria (Published)
This study examined the percentage contribution of squall lines and thunderstorms to annual rainfall amount over the Middle Belt region of Nigeria, using Jos and Makurdi as representative stations, based on daily records obtained from the Nigerian Meteorological Agency (NiMet) covering 1995–2024. Mean, Standard of Deviation, Coefficient of Variation, percentage Students t-test and trend analysis were employed in data analysis. The results indicate that both squall lines and thunderstorms were largely confined to the rainy season (March–October), with thunderstorms occurring far more frequently than squall lines at both stations. Thunderstorms accounted for the dominant share of annual rainfall, contributing 48.69% in Jos and 42.17% in Makurdi, while squall lines contributed a comparatively smaller proportion of 17.53% and 14.47%, respectively. The combined contribution of both systems therefore accounted for the majority of annual rainfall in the region, underscoring their central role in the Middle Belt’s hydro-climatic regime. Trend analysis revealed that the percentage contribution of squall lines declined significantly over the study period in Jos and marginally in Makurdi, while the contribution of thunderstorms also declined significantly in Jos but showed no significant trend in Makurdi. Despite these declines in relative contribution, total annual rainfall at both stations exhibited no significant long-term trend, suggesting a shifting balance in the convective mechanisms sustaining regional rainfall. The study concludes that squall lines and thunderstorms remain the principal drivers of annual rainfall over the Middle Belt, but their relative contributions are undergoing measurable change consistent with broader climate variability. The study recommended that NiMet enhance convective-system monitoring and that findings be incorporated into climate-smart agricultural planning and flood-risk management strategies for the region.
Keywords: Jos, Makurdi, Middle Belt region, Thunderstorms, climate variabilit, rainfall contribution, squall lines