Spectral analysis using long-term brightness temperature data highlights the presence of pronounced and significant 3-4 day periodicity in convection over central Sudan and adjacent western Ethiopia during the boreal summer season, a region not well known for synoptic scale wave activity. Composite analysis using a lag regression technique indicates that much of this variability arises in association with a regional oscillation that takes place between East Africa and the equatorial Congo region. The mechanism to explain this marked oscillation involves two key processes: (i) A local convective recharge-discharge process associated with periods of increasing conditional instability (charging) and decreasing conditional instability (discharging) and (ii) A dynamic interaction between the two regions associated with low-level moisture transport. A conceptual model will be presented to illustrate these processes and the consequences of this oscillation for the regional climate and climate variability will be discussed.