Despite recent decreases in rainfall, torrential rains have caused flooding across sub-Saharan Africa
Africa Weather Hazards
Since early August, above-average seasonal rainfall caused flooding in some areas. With well above-average moisture conditions, additional rain in September may trigger flooding in parts of Senegal,
The Gambia, Guinea-Bissau, Guinea, and Sierra Leone.Recent heavy rains have caused the Benue River in Nigeria to overflow its banks. Reports indicate that 100,000 people may have been displaced by flooding. Continued rainfall will keep rivers high.
Heavy rainfall triggered flooding in Sudan during the last week. Both the Blue and White Nile rivers are effected, and a dam has reportedly broken along the White Nile. Although rainfall is expected to decrease throughout the region in early September, saturated ground conditions sustain the risk for additional flooding.
Africa Overview
West Africa experiences a decrease in rainfall
According to the latest satellite rainfall estimates, many areas of Senegal, Mali, and Nigeria registered below-normal rainfall totals. Despite these broad decreases, Niamey, Niger and Benue state in Nigeria still received very heavy rain which has led to flooding. Over 100mm of rain was recorded in Niamey last week. Other areas that received heavy rain (>100mm) include eastern Burkina Faso, northern Benin, Guinea, and Sierra Leone (Figure 1). Rains have begun to lessen across the Sahel and little to no rain was observed in southern Cote D’Ivoire and Ghana.
August was characterized by a general decrease in seasonal rainfall, with an increase in rainfall towards the month’s end. The observed recovery was short lived, as rains lessened again to start September. In parts of southern Burkina Faso, northern Ghana, and Liberia, rainfall deficits exceed 50mm and less than 80% of normal over the last 30 days. Large seasonal moisture surpluses persist in western Gulf of Guinea regions and some portions of the Sahel, where parts of Guinea and Mali have experienced more than twice their normal rainfall accumulation since late July (Figure 2). The continuation of heavy seasonal rains in these areas elevates the risk for floods in September.
Next week, weather models suggest the potential for abovenormal rainfall for western Gulf of Guinea countries. The rest of the region is likely to receive seasonable conditions.