Filling Critical Gaps: An Empirical Assessment of Mesoscale Convective System Tracks Over Nigeria Using MSG Satellite Data

Mesoscale Convective Systems (MCS) are the dominant precipitation-producing weather systems over West Africa, yet systematic tracking of their characteristics and trajectories over Nigeria remains a significant gap in Nigerian meteorological literature. This study empirically characterizes MCS tracks, propagation speeds, and lifecycle parameters over Nigeria using Meteosat Second Generation (MSG) brightness temperature data from the EUMETSAT archive for six rainy seasons from 2018 to 2023. MCS objects were identified and tracked using the Flexible Object Tracker (FLEXTRKR) algorithm applied to 15-minute MSG channel 9 infrared imagery. Tracked systems were classified into long-lived organized MCS events and shorter-lived convective clusters based on size, duration, and propagation criteria. A total of 1,847 MCS events were tracked over Nigeria during the study period, with a mean propagation speed of 13.4 metres per second in a west-to-east dominant direction. Seasonal analysis confirms that the largest and most long-lived MCS events occur in August and September over the North Central and South West zones, while the North East zone experiences peak MCS activity in July. Orographic enhancement of MCS rainfall intensity over the Jos Plateau and Mambilla Plateau is confirmed through comparison of MCS tracks with IMERG satellite rainfall estimates. The empirical MCS climatology developed fills a documented gap in Nigerian meteorological research and provides a reference dataset for evaluating NiMet's convection-permitting operational model. Keywords: mesoscale convective systems, MSG satellite, tracking, Nigeria, rainfall climatology.