During the 2002 summer monsoon season, the IMPETUS (Integrated Project for the Management of Scarce Fresh Water Resources) field campaign collected high-quality meteorological and hydrological observations near the headwaters of the Oueme River in the West African nation of Benin. Somewhat equatorward of the Sahel, the Upper Oueme Valley experienced a several different mesoscale regimes of heavy precipitation, including examples of classic West African squall lines and stationary vortices in the African Easterly Jet. A number of these Mesoscale Convective Systems have been examined in detail to compare their large-scale meteorological environments. Hydrometeor profiles from TRMM Precipitation Radar reveal that the structure of the squall lines is in good agreement with the surface-based observations taken during COPT-81 and HAPEX-SAHEL.