West Africa's Rainfall Patterns and Vegetation Conditions: Highlights and Forecasts

Introduction:
As the rainy season begins in West Africa, the region experiences variable conditions with significant differences in rainfall patterns and vegetation conditions. While some areas have received above-normal rains, others are facing abnormal dryness. These conditions have implications for agriculture, water resources, and flood risks across the region. In this article, we will delve into the highlights of West Africa's current conditions and provide short-term forecasts for the coming weeks.

Variable Rainfall Patterns:
During the early stage of the rainy season (April-May 2023), parts of West Africa have observed above-normal rainfall, particularly in southern Senegal, The Gambia, western Mali, Guinea, Guinea Bissau, western Sierra Leone, and northeastern Nigeria, Cameroon, and Chad. Conversely, central Sahel, southern Burkina Faso, northern Ghana, Cote d'Ivoire, and coastal regions of Nigeria have experienced abnormal dryness. The Sahelian belt has maintained neutral conditions.

Vegetation Conditions and Water Resources:
The early season dryness has resulted in below-average vegetation conditions across an extensive area, stretching from southwestern Chad, northern Cameroon, and Nigeria's Central Belt to northern Benin, Togo, southern Burkina Faso, and western Mali. Vegetation deficits are particularly severe in northern Benin and Nigeria's Central Belt. However, areas of northern Burkina Faso, central Mali, eastern and southwestern Senegal, northern Ghana, central Côte d'Ivoire, northern Nigeria, and southern Chad show better-than-normal vegetation conditions. Water resources remain critically low throughout the Sahel region.

Short-Term Forecasts:
Mid-June (20th June 2023) is expected to bring improvements in rainfall across the West Africa region, especially in the Sahel, leading to more favorable conditions for the start of the growing season. According to the 2022 PRESASS seasonal forecast, above-average to average rainfall is predicted in the far western Sahel (Cap Vert, Senegal, western Guinea, and southwestern Mauritania) and the central Sahel (Mali and parts of northern Burkina Faso). Coastal areas of Gulf of Guinea countries may experience average to below-average seasonal rainfall, posing challenges for crop cultivation and increasing the risk of flooding.

Flood Preparedness and Monitoring:
Efforts to prepare for potential floods highlight administrative areas with medium or high flood risk located in river basins expecting normal to above-normal river levels in 2023. These areas include the Gambia basin, the Falémé basin (Senegal's tributary), the Inner Niger Delta in Mali, the middle Niger river basin, the Komadougou Yobé (in Nigeria), the middle Chari, and the Lower Chari-Logone (in Chad and CAR). Additionally, administrative areas with a high flood risk are identified in the upper Niger River basin (Guinea, Côte d'Ivoire, and Mali), the upper Chari basin, the Lower Niger, the Bafing and Bakoye sub-basins (Senegal basin), the Mono (Togo and Benin), Ouémé (Benin), and the upper and western Volta basin.

Conclusion:
West Africa's weather conditions at the early stage of the rainy season display significant variations, with some areas receiving abundant rainfall and others facing dryness. Vegetation conditions and water resources reflect these patterns, with below-average vegetation observed in several regions. Short-term forecasts suggest improvements in rainfall across the Sahel, potentially alleviating the impacts of early season dryness. However, the ongoing El Niño events and the predicted shift in rainfall patterns pose additional challenges. Flood preparedness and monitoring efforts are crucial to mitigate potential risks and protect vulnerable areas.