7Application of satellite rainfall estimation to flood early warning systems Satellite-based rainfall estimation (rfe) algorithms could potentially provide real time data on extreme rainfall events that could be utilised for flood early warning systems in Africa.Grimes & Diop ’03 studied the feasibility of using satellite rainfall estimates as input to a simple rainfall-runoff hydrological model, in order to forecast river flows. They used the Bakoye catchment area in Mali as a test case. The approach showed some skill at predicting river flow, but without contemporaneous gauge data for calibration (rare in Africa) it was not accurate enough to be useful operationally.Algorithms based on Cold Cloud Duration such as TAMSAT are statistical in nature, and need to be averaged over sufficiently large time and/or space scales to produce accurate estimates. For river flow forecasting time scales need to be of the order of a day or less, so the corresponding space scales must be an area of several thousand km squared. Therefore this approach is limited to medium to large river basins.