Precipitation in Western Africa follows a clearly seasonal pattern. The forecasts of seasonal precipitation and the incorporation of their error bounds are invaluable in water resources planning and operations under uncertainty. In this paper the relationships between the seasonal precipitation in several western Africa sites and climatic precursors like the SST in the Equatorial Pacific are analyzed and their predictive skills are evaluated using simpler relationships and adaptive filtering techniques like the one proposed by Liu et al (1997,1998).
The forecasts also include uncertainty intervals and confidence limits. The forecasts are based on the temporal and spatial variability of standarized precipitation anomalies and their relationships with climatic interannual and intraseasonal El Niņo-Southern Oscillation (ENSO).
The performance skills of the alternative models are compared for the period of record and also for the last ENSO episode.