The African Monsoon Recent Evolution and Current Status

The African Monsoon Recent Evolution and Current Status Include Week-1 and Week-2 Outlooks Update prepared by Climate Prediction Center / NCEP 06 March 2017 For more information, visit: http: //www. cpc. ncep. noaa. gov/products/Global_Monsoons/African_Monsoons/precip_monitoring. shtml

Outline • Highlights • Recent Evolution and Current Conditions • NCEP GEFS Forecasts • Summary

Highlights: Last 7 Days • Weekly total rainfall exceeded 150 mm over parts of northern Namibia, local areas in eastern Angola, portions of southern DRC, Zambia, and central Mozambique. • Week-1 outlooks call for an increased chance for above-average rainfall over parts of southern Angola and northern Namibia, portions of southern DRC, much of Zambia, and much of Madagascar. In contrast, there is an increased chance for belowaverage rainfall over portions of Botswana, South Africa, Lesotho, Swaziland, southern Zimbabwe, southern Mozambique, portions of Ethiopia, Uganda, northern Tanzania and Kenya.

Rainfall Patterns: Last 7 Days During the past seven days, rainfall was below-average over parts of southern Cameroon, Equatorial Guinea, Gabon, portions of Congo-Brazzaville and RC, many parts of Angola, local areas in Uganda and northeastern Mozambique, and portions of Madagascar. In contrast, local areas in southern Nigeria, parts of Angola and DRC, northern Namibia, much of Zambia, Tanzania, Malawi, portions of Mozambique, and southern Madagascar had above-average rainfall.

Rainfall Patterns: Last 30 Days During the past 30 days, rainfall was above-average over parts of Liberia and Cote d’Ivoire, local areas in Nigeria, portions of Ethiopia, local areas in Congo-Brazzaville, parts of Angola and DRC, Uganda, many parts of Tanzania, Zambia, Namibia, Botswana, Zimbabwe, South Africa, Malawi, portions of Mozambique, and southern Madagascar. In contrast, portions of Ghana and Cote d’Ivoire, parts of Nigeria, Cameroon, CAR, Equatorial Guinea, parts of Gabon and Congo-Brazzaville, many parts of Angola, portions of DRC, local areas in Tanzania and Kenya, northern Mozambique and northern Madagascar had below-average rainfall.

Rainfall Patterns: Last 90 Days During the past 90 days, rainfall was above-average over eastern Liberia, southern Cote d’Ivoire, southern Ghana, Equatorial Guinea, local areas in Gabon and Congo-Brazzaville, portions of DRC, local areas in Ethiopia, parts of southeastern Angola, portions of DRC, Namibia, Botswana, Zimbabwe, much of South Africa, Lesotho, Swaziland, Malawi, and central and southern Mozambique, and local areas in Madagascar. In contrast, below-average rainfall was observed over local areas in Nigeria, Cameroon, portions of Gabon and Congo-Brazzaville, much of Angola, parts of DRC, Rwanda, Burundi, local areas in Ethiopia, parts of Uganda, Kenya, local areas in Somalia, much of Tanzania, northern Mozambique, and much of Madagascar.

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

Recent Rainfall Evolution Daily evolution of rainfall over the last 90 days at selected locations shows that seasonal total rainfall remained belowaverage over parts of Angola (bottom left) and Madagascar (top right). In contrast, moderate to heavy rainfall sustained moisture surpluses over parts of Zambia (bottom right).

Atmospheric Circulation: Last 7 Days Anomalous lower-level moist easterly flow prevailed across northern portions of Southern Africa (left panel).

NCEP GEFS Model Forecasts Non-Bias Corrected Probability of precipitation exceedance Week-1: 7 – 13 Mar, 2017 Week-2: Valid 14 – 20 Mar, 2017 For week-1 (left panel), there is an increased chance for weekly rainfall totals to exceed 50 mm over portions of southern Angola, much of Zambia, parts of DRC, northern Malawi, southern Tanzania, and much of Madagascar.

Week-1 Precipitation Outlooks 1. There is an increased chance for above-average rainfall over parts of southern Angola and northern Namibia: An area of anomalous lower-level convergence and upper-level divergence is expected to enhance rainfall in the region. Confidence: Moderate 2. There is an increased chance for above-average rainfall over parts of southern DRC and much of Zambia: An area of anomalous lower-level convergence is expected to enhance rainfall in the region. Confidence: Moderate 3. There is an increased chance for below-average rainfall over portions of Botswana, South Africa, Lesotho, Swaziland, southern Zimbabwe and southern Mozambique: A broad area of anomalous lower-level divergence and upper-level convergence is expected to suppress rainfall in the region. Confidence: Moderate 4. There is an increased chance for below-average rainfall over parts of Ethiopia, Uganda, northern Tanzania and Kenya: Anomalous lower-level divergent flow is expected to suppress rainfall in the region. Confidence: Moderate 5. There is an increased chance for above-average rainfall over much of Madagascar: An area of anomalous lower-level cyclonic circulation and the passage of tropical cyclone is expected to enhance rainfall in the region. Confidence: Moderate 7 – 13 Mar, 2017

Week-2 Precipitation Outlooks 14 – 20 Mar, 2017 1. There is an increased chance for above-average rainfall over parts of northern Angola: An area of anomalous lower -level convergence and upper-level divergence is expected to enhance rainfall in the region. Confidence: Moderate 2. There is an increased chance for below-average rainfall over southeastern Angola, parts of western Zambia, eastern Namibia, much of Botswana, western Zimbabwe and northern South Africa: An area of anomalous lowerlevel anti-cyclonic flow and upper-level convergence is expected to suppress rainfall in the region. Confidence: Moderate

Summary • During the past seven days, rainfall was below-average over parts of southern Cameroon, Equatorial Guinea, Gabon, portions of Congo-Brazzaville and RC, many parts of Angola, local areas in Uganda and northeastern Mozambique, and portions of Madagascar. In contrast, local areas in southern Nigeria, parts of Angola and DRC, northern Namibia, much of Zambia, Tanzania, Malawi, portions of Mozambique, and southern Madagascar had above-average rainfall. • During the past 30 days, rainfall was above-average over parts of Liberia and Cote d’Ivoire, local areas in Nigeria, portions of Ethiopia, local areas in Congo-Brazzaville, parts of Angola and DRC, Uganda, many parts of Tanzania, Zambia, Namibia, Botswana, Zimbabwe, South Africa, Malawi, portions of Mozambique, and southern Madagascar. In contrast, portions of Ghana and Cote d’Ivoire, parts of Nigeria, Cameroon, CAR, Equatorial Guinea, parts of Gabon and Congo-Brazzaville, many parts of Angola, portions of DRC, local areas in Tanzania and Kenya, northern Mozambique and northern Madagascar had below-average rainfall. • During the past 90 days, rainfall was above-average over eastern Liberia, southern Cote d’Ivoire, southern Ghana, Equatorial Guinea, local areas in Gabon and Congo-Brazzaville, portions of DRC, local areas in Ethiopia, parts of southeastern Angola, portions of DRC, Namibia, Botswana, Zimbabwe, much of South Africa, Lesotho, Swaziland, Malawi, and central and southern Mozambique, and local areas in Madagascar. In contrast, below-average rainfall was observed over local areas in Nigeria, Cameroon, portions of Gabon and Congo-Brazzaville, much of Angola, parts of DRC, Rwanda, Burundi, local areas in Ethiopia, parts of Uganda, Kenya, local areas in Somalia, much of Tanzania, northern Mozambique, and much of Madagascar. • Week-1 outlooks call for an increased chance for above-average rainfall over parts of southern Angola and northern Namibia, portions of southern DRC, much of Zambia, and much of Madagascar. In contrast, there is an increased chance for below-average rainfall over portions of Botswana, South Africa, Lesotho, Swaziland, southern Zimbabwe, southern Mozambique, portions of Ethiopia, Uganda, northern Tanzania and Kenya.