Intensification of rainfall is projected for the Sahel rainy season, including large increases in wet spell frequency, wet spell duration, and wet spell intensity. These changes are statistically significant at mid-21th century, and become more spatially robust by the end of the century. A weaker intensified rainfall trend is also projected over East Africa, for northern Ethiopia in boreal summer, Tanzania in boreal winter, and southern Ethiopia, Somalia, and the Lake Victoria region in boreal fall. The changes are significant in scattered regions at mid-21st c., but widespread and highly significant by the end of the century. In contrast, increased drought is projected for southeast Africa (Angola, Zambia, Malawi), including 50%-100% reductions in wet spell frequency annually and increases in dry spell duration in austral spring.
The spatial coherence and rigorous statistical analysis of the projected changes combined with their physical consistency with the findings of previous studies support confidence in these results.