African Monsoon: Recent Evolution and Outlook Update

1. The African Monsoon Recent Evolution and Current StatusInclude Week-1 and Week-2 Outlooks Update prepared by Climate Prediction Center / NCEP 11 February 2019 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 • Weekly rainfall surpluses exceeded 50mm over parts of Zambia, southern Tanzania, northern Malawi, and local areas in Mozambique and northern Madagascar. • Week-1 outlooks call for an increased chance for below-average rainfall across southwestern Angola, northwestern Namibia, parts of eastern DRC, Rwanda, Burundi, Uganda, southern Kenya, much of Tanzania, Malawi, and northern Mozambique. There is an increased chance for above-average rainfall across eastern Botswana, much Zimbabwe, southern Zambia, central and southern Mozambique, northeastern South Africa and Swaziland.

4. Rainfall Patterns: Last 7 Days Weekly rainfall totals exceeded 100mm over parts of Tanzania and Zambia, northern Malawi, and local areas in northern Mozambique and northern Madagascar. Rainfall was above-average northern Cote d’Ivoire, Gabon, local areas in CAR and South Sudan, much of DRC, many parts of Angola, Zambia and Tanzania, much of Malawi, portions of Botswana, northern Mozambique, and parts of northern Madagascar. Equatorial Guinea, Gabon, Southern Congo-Brazzaville, northwestern and southeastern Angola, many parts of Namibia, local areas in Zambia, northern Botswana, central and southern Mozambique, and western and southern Madagascar had below-average rainfall.

5. Rainfall Patterns: Last 30 Days During the past 30 days, rainfall was above-average along the Gulf of Guinea coast, southern CAR, northern Congo-Brazzaville, many parts of DRC, local areas in Angola, many parts of Tanzania, portions of Zambia, local area in Botswana, parts of South Africa, northern Malawi, and portions of Mozambique and Madagascar. Below-average rainfall was observed over Equatorial Guinea, much of Gabon local areas in DRC, southwestern Ethiopia, many parts of Uganda and Kenya, local areas in northern Tanzania, many parts of Angola, Namibia, portions of Botswana, southern Zambia, Zimbabwe, parts of South Africa, portions of northern Mozambique, and many parts of Madagascar.

6. Rainfall Patterns: Last 90 Days During the past 90 days, portions of Guinea-Conakry, Sierra Leone, Côte d’Ivoire, local areas in Ghana and Benin, parts of Nigeria and Cameroon, southern Central African Republic, much of Congo-Brazzaville, many parts of DRC, local areas in Ethiopia, Somalia and Kenya, much of Tanzania, parts of Angola, eastern Zambia, Malawi, many parts of Mozambique, Botswana and South Africa, and portions of Madagascar had above-average rainfall. Rainfall was below-average over parts of Liberia and Ghana, Togo, local areas in Cameroon, Equatorial Guinea, Gabon, northern CAR, portions of DRC, southern South Sudan, parts of Ethiopia and Uganda, parts of Somalia and Kenya. Below-average rainfall was also observed over many parts of Angola, Namibia, western Zambia, Zimbabwe, parts of Botswana and South Africa, and portions of Madagascar.

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

8. Recent Rainfall Evolution Daily evolution of rainfall over the last 90 days at selected locations shows that seasonal total rainfall remained below-average over southern Angola (left panel) and western Zambia (bottom left). Moderate to heavy rainfall sustained moisture surpluses over parts of Malawi (top right).

9. Atmospheric Circulation:Last 7 Days An area of anomalous lower-level anti-cyclonic flow was observed across southeastern Africa.

10. NCEP GEFS Model ForecastsNon-Bias Corrected Probability of precipitation exceedance Week-1: Valid 12 – 18 February 2019 Week-2: Valid 19 – 25 February 2019 For week-1 (left panel) , there is an increased chance for weekly rainfall totals to exceed 50 mm over local areas in Ethiopia and DRC, southeastern Zambia, eastern Botswana, much of Zimbabwe, eastern South Africa, southern Mozambique, and Madagascar. For week-2 (right panel), there is an increased chance for weekly rainfall totals to exceed 50 mm over parts of DRC, northern Angola, eastern Zambia, northern Mozambique, local areas in Ethiopia and Malawi, and parts of Madagascar.

11. Week-1 Precipitation Outlooks 12 - 18 February, 2019 • There is an increased chance for below-average rainfall across southwestern Angola and northwestern Namibia: An area of anomalous lower-level divergence and upper-level convergence is expected to suppress rainfall in the region. Confidence: Moderate • There is an increased chance for above-average rainfall across eastern Botswana, parts of southern Zambia, much of Zimbabwe, northeastern South Africa, Swaziland, and central and southern Mozambique: An area of anomalous lower-level convergence and upper-level divergence is expected to enhance rainfall in the region. Confidence: Moderate • There is an increased chance for below-average rainfall across parts of eastern DRC, Rwanda, Burundi, Uganda, southern Kenya, much of Tanzania, Malawi and northern Mozambique: An area of anomalous lower-level divergence and upper-level convergence, combined with the projected phase of the MJO is expected to suppress rainfall in the region. Confidence: Moderate

12. Week-2 Precipitation Outlooks 19 - 25 February, 2019 • There is an increased chance for below-average rainfall throughout southern Angola, northern Namibia, southwestern Zambia, northern Botswana and much of Zimbabwe: An area of anomalous lower-level divergence and upper-level convergence is expected to suppress rainfall in the region. Confidence: Moderate • There is an increased chance for above-average rainfall throughout parts of Congo-Brazzaville, northern Angola, and western and southern DRC: An area of anomalous lower-level convergence and upper-level divergence is expected to enhance rainfall in the region. Confidence: Moderate • There is an increased chance for below-average rainfall across much of Tanzania, and the neighboring areas of eastern Zambia northern Malawi and northern Mozambique: An area of anomalous lower-level divergence and upper-level convergence is expected to suppress rainfall in the region. Confidence: Moderate

13. Summary • Weekly rainfall totals exceeded 100mm over parts of Tanzania and Zambia, northern Malawi, and local areas in northern Mozambique and northern Madagascar. Rainfall was above-average northern Cote d’Ivoire, Gabon, local areas in CAR and South Sudan, much of DRC, many parts of Angola, Zambia and Tanzania, much of Malawi, portions of Botswana, northern Mozambique, and parts of northern Madagascar. Equatorial Guinea, Gabon, Southern Congo-Brazzaville, northwestern and southeastern Angola, many parts of Namibia, local areas in Zambia, northern Botswana, central and southern Mozambique, and western and southern Madagascar had below-average rainfall. • During the past 30 days, rainfall was above-average along the Gulf of Guinea coast, southern CAR, northern Congo-Brazzaville, many parts of DRC, local areas in Angola, many parts of Tanzania, portions of Zambia, local area in Botswana, parts of South Africa, northern Malawi, and portions of Mozambique and Madagascar. Below-average rainfall was observed over Equatorial Guinea, much of Gabon local areas in DRC, southwestern Ethiopia, many parts of Uganda and Kenya, local areas in northern Tanzania, many parts of Angola, Namibia, portions of Botswana, southern Zambia, Zimbabwe, parts of South Africa, portions of northern Mozambique, and many parts of Madagascar. • During the past 90 days, portions of Guinea-Conakry, Sierra Leone, Côte d’Ivoire, local areas in Ghana and Benin, parts of Nigeria and Cameroon, southern Central African Republic, much of Congo-Brazzaville, many parts of DRC, local areas in Ethiopia, Somalia and Kenya, much of Tanzania, parts of Angola, eastern Zambia, Malawi, many parts of Mozambique, Botswana and South Africa, and portions of Madagascar had above-average rainfall. Rainfall was below-average over parts of Liberia and Ghana, Togo, local areas in Cameroon, Equatorial Guinea, Gabon, northern CAR, portions of DRC, southern South Sudan, parts of Ethiopia and Uganda, parts of Somalia and Kenya. Below-average rainfall was also observed over many parts of Angola, Namibia, western Zambia, Zimbabwe, parts of Botswana and South Africa, and portions of Madagascar. • Week-1 outlooks call for an increased chance for below-average rainfall across southwestern Angola, northwestern Namibia, parts of eastern DRC, Rwanda, Burundi, Uganda, southern Kenya, much of Tanzania, Malawi, and northern Mozambique. There is an increased chance for above-average rainfall across eastern Botswana, much Zimbabwe, southern Zambia, central and southern Mozambique, northeastern South Africa and Swaziland.