Seasonal rainfall deficits continue to strengthen across the Greater Horn of Africa
Seasonal rainfall deficits since October have resulted in significant dryness across Angola, Namibia, Zambia, and Zimbabwe.
Continued below-average rainfall and high temperatures have strengthened moisture deficits in South Sudan, Ethiopia, Uganda, Kenya, Somalia, and Tanzania.
Parts of eastern Ethiopia and Somalia receive little to no rainfall Last week, increased seasonal rainfall was received in southwestern Ethiopia and parts of South Sudan, with well distributed weekly amounts exceeding 50mm. Parts of central Ethiopia continued to receive light rainfall, while east of the Oromia, little to no precipitation was registered, delaying the start of season (Figure 1). Similarly, parts of Somalia, Kenya, and northern Tanzania saw no increase in seasonal precipitation, except for isolated activity along the Kenya and Somalia border. Seasonable rainfall was received across parts of Uganda, Rwanda and Burundi.
A rapid strengthening of anomalous dryness has been observed across East Africa over the past several weeks, with notable moisture deficits of 25-200 mm, reflecting a delayed start of season in eastern Ethiopia and Somalia, and poor rainfall performance in parts of Uganda, Kenya, and northern Tanzania (Figure 2).
Coupled with the effects of above-average temperatures and below-average rainfall since early March, the continued belowaverage rainfall this month is increasingly likely to worsen ground conditions. Additionally, poor rainfall from the October-December rainfall season last year, is likely to amplify already dry conditions across the Greater Horn.
Next week, increased rainfall is possible over eastern Ethiopia and northern Somalia, however below-average precipitation is expected across central and southern Somalia, Kenya, northern Tanzania, South Sudan and Uganda into late April.
Increased rainfall in many Gulf of Guinea countries Last week, heavy rainfall was received across parts of southern Cote d’Ivoire, Ghana, Benin, and southwestern Nigeria, with amounts exceeding 100mm causing floods in some areas. In Nigeria, the increased rainfall marked the first week of favorable moisture following a slow start to the rainfall season, though anomalous dryness persists throughout the central and southwestern parts of the region (Figure 2). Meanwhile, above-average moisture conditions remain in eastern Guinea, Liberia, Cote d’Ivoire, and Ghana.
Next week, a return to drier conditions across Nigeria is expected with more seasonable rainfall forecast over the western Gulf of Guinea countries.