Special issue  

Dry spells can have a devastating impact on agricuture in areas where irrigation is not available. Forecasting these dry spells could enhance preparedness in sensitive regions and avoid economic loss due to harvest failure. In this study, ECMWF seasonal forecasts are applied in the Limpopo basin in southeastern Africa to forecast dry spells in the seasonal rains. The results indicate skill in the forecast which is further improved by post-processing of the precipitation forecasts.

Western Pacific SST gradients influence eastern East African precipitation in predictable ways. At seasonal and decadal timescales, warm equatorial western Pacific SSTs and cool eastern Pacific SSTs reduce precipitation in East Africa. The gradient between these regions can be used to make reasonably accurate forecasts in one of the world's most food-insecure regions. Recent warming in the western Pacific and stationary eastern Pacific conditions have produced large precipitation declines.