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 27 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 surpluses exceeded 100 mm over portions of Central Mozambique. • Week-1 outlooks call for an increased chance for above-average rainfall over northwestern Angola, parts of southern Tanzania, Malawi, northern Mozambique and northern Madagascar. In contrast, there is an increased chance for below-average rainfall over central and eastern Angola, portions of southern DRC, northeastern Namibia and northern Botswana, and western and central Zambia.

Rainfall Patterns: Last 7 Days During the past seven days, rainfall was above-average over local areas in Cote d’Ivoire, southern Ghana, southwestern Nigeria, portions of Cameroon, Equatorial Guinea, parts of Congo-Brazzaville, coastal Angola, local areas in Namibia, CAR, many parts of DRC, Zambia, northern Zimbabwe, Malawi, Mozambique, and parts of Uganda and Ethiopia. In contrast, Gabon, central Congo-Brazzaville, local areas in DRC, local areas in Zambia, parts of Tanzania and Kenya, and much of Madagascar had below -average rainfall.

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

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

Rainfall Patterns: Last 180 Days During the past 180 days, rainfall was above-average over local areas in Senegal and Mali, Guinea-Conakry, Sierra Leone, portions of Liberia, much of Cote d’Ivoire, central and southern Ghana, parts of southern Nigeria, CAR, local areas in South Sudan, southern Sudan, portions of Ethiopia, parts of Congo-Brazzaville, local areas in Angola, northwestern DRC, Namibia, Botswana, Zimbabwe, Malawi, Zambia, many parts of South Africa, Lesotho, Swaziland, and central and southern Mozambique, and parts of Madagascar. In contrast, below-average rainfall was observed over portions of Senegal and Liberia, parts of northern Ghana, Burkina Faso, Benin, Togo, portions of Nigeria, Cameroon, Gabon, portions of DRC, many parts of Angola, portions of southern Ethiopia, Somalia, Kenya, Uganda, Tanzania, Rwanda, Burundi, southern South Africa, northern Mozambique, and many parts 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). In contrast, moderate to locally heavy rainfall sustained moisture surpluses over parts of Mozambique (bottom right), and portions of costal Tanzania (top right).

Atmospheric Circulation: Last 7 Days An area of anomalous upper-level divergent flow across southeastern Africa may have contributed to observed above-average rainfall in the region.

NCEP GEFS Model Forecasts Non-Bias Corrected Probability of precipitation exceedance Week-1: Mar 28 – Apr 3, 2017 Week-2: Valid 04 – 10 April 2017 For week-1 (left panel) and week-2 (right panel), there is an increased chance for weekly rainfall totals to exceed 50 mm over portions of Gabon, southern and eastern DRC, northwestern Angola, eastern Ethiopia, parts of Tanzania, northern Mozambique and Madagascar.

Week-1 Precipitation Outlooks Mar 28 – Apr 3, 2017 1. There is an increased chance for above-average rainfall over northwestern Angola: An area of anomalous lowerlevel 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 central and eastern Angola, portions of southern DRC, northeastern Namibia and northern Botswana, and western and central Zambia: An area of anomalous lowerlevel anti-cyclonic circulation and upper level-convergence is expected to suppress rainfall in the region. Confidence: Moderate 3. There is an increased chance for above-average rainfall over parts of southern Tanzania, Malawi, northern Mozambique and northern Madagascar: An area of anomalous lower-level cyclonic circulation and upper-level divergence is expected to enhance rainfall in the region. Confidence: Moderate

Week-2 Precipitation Outlooks 4 – 10 April, 2017 1. There is an increased chance for below-average rainfall over portions of northern DRC, and western Zambia: An area of anomalous lower-level divergence and upper-level convergence is expected to suppress rainfall in the region. Confidence: Moderate 2. There is an increased chance for above-average rainfall over parts of eastern Zambia and southern Tanzania, Malawi, and northern Mozambique: An area of anomalous lower-level convergence and upper-level divergence is expected to enhance rainfall in the region. Confidence: Moderate

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