The African Monsoon Recent Evolution and Current Status Include Week-1 and Week-2 Outlooks

1. The African Monsoon Recent Evolution and Current StatusInclude Week-1 and Week-2 Outlooks Update prepared by Climate Prediction Center / NCEP 10 October 2016 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 • Above-average rainfall was observed over portions of the Central Africa countries, including the Lake Victoria region. • Week-1 outlooks call for an increased chance for above-average rainfall over Guinea, Sierra Leone and Liberia. In contrast, there is an increased chance for below-average rainfall over northeastern Angola, portions of DRC, South Sudan, Uganda, and portions of southeastern Somalia and southern Somalia.

4. Rainfall Patterns: Last 7 Days During the past seven days, rainfall was above-average over many parts of Cote d’Ivoire, parts of Ghana, local areas in Nigeria, much of CAR, northern DRC, parts of Congo-Brazzaville, southern Sudan, portions of South Sudan Republic, Uganda, Rwanda, Burundi, and portions of Tanzania and western Ethiopia. In contrast, parts of Sierra Leone and Liberia, portions of Nigeria, Cameroon, parts of Gabon, and local areas in Angola and Ethiopia had below-average rainfall.

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

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

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

8. Recent Rainfall Evolution Daily evolution of rainfall over the last 90 days at selected locations shows seasonal total rainfall remained above-average over Sierra Leone (bottom left) and eastern Sudan (top right), while below-average rainfall prevailed over parts of southern Ethiopia(bottom right).

9. Atmospheric Circulation:Last 7 Days The 700 hPa (left panel) wind anomalies featured westerly flow with its associated lower-level convergence across Central Africa, which may have contributed to the observed above-average rainfall in the region.

10. NCEP GEFS Model ForecastsNon-Bias Corrected Probability of precipitation exceedance Week-1: Valid 11 – 17 Oct, 2016 Week-2: Valid 18 – 24 Oct, 2016 For week-1 (left panel) and week-2 (right panel), there is an increased chance for weekly rainfall totals to exceed 50mm over local areas in Sierra Leone, southeastern Nigeria, parts of Cameroon, northeastern DRC, and portions of Ethiopia.

11. Week-1 Precipitation Outlooks 11 – 17 Oct, 2016 • There is an increased chance for above-average rainfall over portions of Guinea, Sierra Leone, and Liberia: An area of anomalous lower level convergence and anomalous upper-level divergence is expected to enhance rainfall in the region. Confidence: Moderate • There is an increased chance for below-average rainfall over portions of central and southern DRC and northeastern Angola:An area of anomalously strong lower-level divergence and upper-level convergence is expected to suppress rainfall in the region. Confidence: Moderate • There is an increased chance for below-average rainfall over portions of South Sudan, Uganda, and northeastern DRC:An area of anomalously strong lower-level divergence and upper-level convergence is expected to suppress rainfall in the region.Confidence: Moderate • There is an increased chance for below-average rainfall over southeastern Ethiopia, and southern Somalia: An area of anomalous lower-level divergence is expected to suppress rainfall in the region. Confidence: Moderate

12. Week-2 Precipitation Outlooks 18 – 24 Oct, 2016 • There is an increased chance for above-average rainfall over portions of Guinea, Sierra Leone, and Liberia: Anomalous lower level convergence is expected to enhance rainfall in the region. Confidence: Moderate • There is an increased chance for below-average rainfall over Nigeria: Anomalous lower-level divergence and upper level convergence is expected to suppress rainfall in the region. Confidence: Moderate • There is an increased chance for below-average rainfall over portions of northern CAR, eastern Chad, southern Sudan and South Sudan: Anomalous lower-level divergence and upper-level convergence is expected to suppress rainfall in the region. Confidence: Moderate

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