The European Centre for Medium-Range Forecasts (ECMWF) recently implemented a revised annually varying aerosol climatology in their forecasting system. The new climatology greatly reduces the aerosol optical depth over the Sahara compared to the previous time-invariant climatology. Using high resolution dropsonde data in addition to the model analyses, it is demonstrated that the direct radiative effect resulting from the aerosol climatology modification significantly improves the ECMWF 5-day forecasts of the African Easterly Jet, the central dynamical feature in this region.