1. The African Monsoon Recent Evolution and Current Status Include Week-1 and Week-2 Outlooks Update prepared by Climate Prediction Center / NCEP 28 September 2015 For more information, visit: http://www.cpc.ncep.noaa.gov/products/Global_Monsoons/African_Monsoons/precip_monitoring.shtml

2. Outline Highlights Recent Evolution and Current Conditions NCEP GEFS Forecasts Summary

3. Highlights: Last 7 Days Portions of the Sahel region received above-average rainfall, whereas moisture deficits prevailed over many places of the Gulf of Guinea countries. Week-1 outlooks call for an increased chance for above-average rainfall over southeastern Ethiopia and the neighboring places of northeastern Kenya and central Somalia. In contrast, there is an increased chance for below-average rainfall over southern Ghana, Togo, Benin, western Nigeria, eastern South Sudan Republic, portions of western Ethiopia and northern Uganda.

4. Rainfall Patterns: Last 7 Days During the past seven days, much of Senegal, southern Mauritania, southern Mali, western Burkina Faso, southwestern Niger, portions of northern Nigeria, southern Chad, Congo- Brazzaville, local areas in DRC, Portions of southern Sudan, northwestern Ethiopia, and northern South Sudan Republic received above-average rainfall. In contrast, rainfall was below- average over Guinea, Sierra Leone, Liberia, Cote d’Ivoire, Ghana, Togo, Benin, much of Nigeria, Cameroon, Equatorial Guinea, Gabon, portions of CAR and DRC, local areas in Ethiopia, and portions of Uganda.

5. Rainfall Patterns: Last 30 Days During the past 30 days, rainfall was above-average over southern Mauritania, portions of Senegal, Mali, Guinea-Conakry, local areas in Sierra Leone and Liberia, Burkina Faso, portions of northern Ghana, northern Togo, northern Benin, southern Niger, northern Nigeria, portions of Cameroon, southern Chad, western CAR, southern and eastern Sudan, northern South Sudan Republic, Eritrea, northern Ethiopia, portions of DRC, northeastern Angola and portions of South Africa. In contrast, below-average rainfall was observed over portions of Guinea-Bissau, local areas in Guinea-Conakry, portions of Sierra Leone and Liberia, much of Cote d’Ivoire and Ghana, southern Togo, southern Benin, central and southern Nigeria, portions of Cameroon, Equatorial Guinea, Gabon, local areas in Congo-Brazzaville, eastern in CAR, many parts of DRC, local areas in South Sudan, much of Uganda, southern and central Ethiopia, and western Kenya had below-average rainfall.

6. Rainfall Patterns: Last 90 Days During the past 90 days, rainfall was above-average over portions of Mauritania, much of Mali, Senegal, Guinea-Bissau, Guinea-Conakry, Sierra Leone, much of Liberia, portions of northern Ghana, much of Burkina Faso, northern Togo, northern Benin, northern Nigeria, portions of Niger, southern Chad, portions of Cameroon and CAR, many parts of South Sudan Republic, southern and eastern Sudan, portions of DRC, local areas in Uganda, portions of Ethiopia and South Africa. In contrast, Cote d’Ivoire, much of Ghana, southern Togo, southern Benin, southern Nigeria, portions of Cameroon, Equatorial Guinea, Gabon, Congo Brazzaville, local areas in central Chad, central CAR, local areas in DRC and northern Angola, much of Uganda, western Kenya, and portions of South Sudan, and eastern Ethiopia received below-average rainfall.

7. Rainfall Patterns: Last 180 Days During the past 180 days, rainfall was above-average over parts of Senegal and Mauritania, much of Guinea, Guinea-Bissau, Sierra Leone, Liberia, Mali, Burkina Faso, portions of Cote d’Ivoire, Niger, portions of Chad, CAR, Gabon, southern Congo-Brazzaville, much of DRC, South Sudan Republic, southern Sudan, southern Somalia, western Ethiopia, Zambia, western Mozambique, Botswana, Zimbabwe, and local areas in South Africa. In contrast, portions of Cote d’Ivoire, Ghana, southern Togo, southern Benin, much of Nigeria, western Cameroon, portions of Angola and South Africa, Mozambique, much of Madagascar portions of southern Tanzania, northern Kenya, northern Somalia, and portions of Ethiopia had below-average rainfall.

8. Recent Rainfall Evolution Daily evolution of rainfall over the last 90 days at selected locations show that moderate to heavy rainfall sustained moisture surpluses over western Burkina Faso(bottom left) and eastern Sudan (top right). Seasonal total rainfall remained below-average over portions of Ghana(bottom right).

9. Atmospheric Circulation: Last 7 Days The 850 hPa wind anomalies (left panel) featured westerly anomalies across the West Africa coast, and easterly anomalies across the equatorial Africa.

10. NCEP GEFS Model Forecasts Non-Bias Corrected Probability of precipitation exceedance Week-1: Valid 29 Sep – 5 Oct 2015 Week-2: Valid 6 – 12 Oct 2015 For week-1 (left panel) and week-2 (right panel), there is an increased chance for rainfall to exceed 50 mm over Sierra Leone, Liberia, southeastern Nigeria, Cameroon, Equatorial Guinea, Gabon, Congo Brazzaville, portions of DRC and northern Somalia.

11. Week-1 Precipitation Outlooks 29 Sep – 5 Oct, 2015 1.There is an increased chance for below-average rainfall over Ghana, Togo, Benin, and western Nigeria: Anomalous low-level divergence, combined with anomalous upper-level convergence is expected to suppress rainfall in the region. Confidence: Moderate 2.There is an increased chance for below-average rainfall over eastern South Sudan northern Uganda: Anomalous low-level divergence, combined with anomalous upper-level convergence is expected to suppress rainfall in the region. Confidence: Moderate 3.There is an increased chance for above-average rainfall over southeastern Ethiopia and parts of central Somalia: Anomalous lower-level convergence combined with upper- level divergence is expected to enhance rainfall in the region. Confidence: Moderate

12. Week-2 Precipitation Outlooks 6 – 12 Oct, 2015 1.There is an increased chance for below-average rainfall over South Sudan and northern Uganda: Anomalous lower-level divergence, combined with anomalous upper- level convergence is expected to suppress rainfall in the region. Confidence: Moderate 2.There is an increased chance for above-average rainfall over southeastern Ethiopia and parts of northern Somalia: Anomalous lower-level convergence combined with upper-level divergence is expected to enhance rainfall in the region. Confidence: Moderate

13. Summary During the past seven days, much of Senegal, southern Mauritania, southern Mali, western Burkina Faso, southwestern Niger, portions of northern Nigeria, southern Chad, Congo-Brazzaville, local areas in DRC, Portions of southern Sudan, northwestern Ethiopia, and northern South Sudan Republic received above- average rainfall. In contrast, rainfall was below-average over Guinea, Sierra Leone, Liberia, Cote d’Ivoire, Ghana, Togo, Benin, much of Nigeria, Cameroon, Equatorial Guinea, Gabon, portions of CAR and DRC, local areas in Ethiopia, and portions of Uganda. During the past 30 days, rainfall was above-average over southern Mauritania, portions of Senegal, Mali, Guinea-Conakry, local areas in Sierra Leone and Liberia, Burkina Faso, portions of northern Ghana, northern Togo, northern Benin, southern Niger, northern Nigeria, portions of Cameroon, southern Chad, western CAR, southern and eastern Sudan, northern South Sudan Republic, Eritrea, northern Ethiopia, portions of DRC, northeastern Angola and portions of South Africa. In contrast, below-average rainfall was observed over portions of Guinea-Bissau, local areas in Guinea-Conakry, portions of Sierra Leone and Liberia, much of Cote d’Ivoire and Ghana, southern Togo, southern Benin, central and southern Nigeria, portions of Cameroon, Equatorial Guinea, Gabon, local areas in Congo-Brazzaville, eastern in CAR, many parts of DRC, local areas in South Sudan, much of Uganda, southern and central Ethiopia, and western Kenya had below-average rainfall. During the past 90 days, rainfall was above-average over portions of Mauritania, much of Mali, Senegal, Guinea-Bissau, Guinea-Conakry, Sierra Leone, much of Liberia, portions of northern Ghana, much of Burkina Faso, northern Togo, northern Benin, northern Nigeria, portions of Niger, southern Chad, portions of Cameroon and CAR, many parts of South Sudan Republic, southern and eastern Sudan, portions of DRC, local areas in Uganda, portions of Ethiopia and South Africa. In contrast, Cote d’Ivoire, much of Ghana, southern Togo, southern Benin, southern Nigeria, portions of Cameroon, Equatorial Guinea, Gabon, Congo Brazzaville, local areas in central Chad, central CAR, local areas in DRC and northern Angola, much of Uganda, western Kenya, and portions of South Sudan, and eastern Ethiopia received below-average rainfall. Week-1 outlooks call for an increased chance for above-average rainfall over southeastern Ethiopia and the neighboring places of northeastern Kenya and central Somalia. In contrast, there is an increased chance for below-average rainfall over southern Ghana, Togo, Benin, western Nigeria, eastern South Sudan Republic, portions of western Ethiopia and northern Uganda.