Probabilistic Seasonal Rainfall Forecast for SOUTHERN AFRICA (Issued on 24 April, 2012)

This seasonal forecast is issued by the South African Weather Service (SAWS). The forecast is a result of a multi-institutional multi-model system that comprises of forecasts from: 1. The CCAM, operated by the CSIR, forced with persisted global SST anomalies; 2. The ECHAM4.5-MOM3-DC2 coupled GCM, administered by the International Research Institute for Climate and Society (IRI); 3. The CFS, a coupled seasonal forecast system administered by NCEP; 4. The ECHAM4.5 AGCM, run locally at SAWS and forced with predicted global SST anomalies. The forecast coarse-resolution large-scale circulation fields of these global models are empirically downscaled to a 0.5x0.5 degree resolution using the Climate Predictability Tool (CPT). There are two sets of maps presented - the maps on the left show the chance of the particular rainfall season being above-normal (wet), and the maps on the right show the chance for below-normal (dry) rainfall totals to occur.

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