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 24 March 2014 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 • Suppressed rainfall prevailed over many places of central, eastern and southern Africa countries, whereas moderate to locally heavy rainfall resulted in moisture surpluses over portion of the Gulf of Guinea region. • Week-1 outlooks call for an increased chance for below-average rainfall over much of Congo Brazzaville, DRC, southern Angola, portions of CAR, and Southeast Africa. In contrast, there is an increased chance for above-average rainfall over southern Ethiopia, portions of Kenya, eastern DRC, Rwanda, Burundi, Tanzania, northern Malawi, and portions of Kenya and Mozambique, the Comoros Islands, and northwestern Madagascar.

4. Rainfall Patterns: Last 7 Days During the past seven days, above-average rainfall was observed over portions of Cote d’Ivoire, much of Ghana, local areas in Benin, southwestern Cameroon, Equatorial Guinea, Gabon, southern Angola, northern Namibia, local areas in eastern Zambia and northern Mozambique, and eastern Madagascar. In contrast, southeastern Nigeria, northern Cameroon, portions of CAR, South Sudan and Ethiopia, much of DRC, central and northern Angola, western Zambia, Uganda, Rwanda, Burundi, Tanzania, portions of Kenya, central Mozambique, western Madagascar, and portions of Zimbabwe and South Africa.

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

6. Rainfall Patterns: Last 90 Days During the past 90 days, local areas in Cote d’Ivoire and Ghana, western Gabon, local areas in CAR and Ethiopia, parts of Tanzania, Zambia, southeastern Angola, eastern Namibia, much of Botswana, Zimbabwe, Mozambique, Malawi, local areas in South Africa, and western Madagascar received above-average rainfall. In contrast, rainfall was below-average over, parts of DRC, many parts of Angola, northwestern Namibia, parts of the Lake Victoria region, and eastern Madagascar.

7. Rainfall Patterns: Last 180 Days During the past 180 days, rainfall was above-average over local areas in Liberia, southern Cote d’Ivoire, southeastern Nigeria, portions of Cameroon, western Gabon, Congo Brazzaville, CAR, local areas in Ethiopia and Somalia, portions of Tanzania, northeastern Namibia, Botswana, local areas in Zambia, much of Zimbabwe, parts of Mozambique and South Africa, and much of Madagascar. In contrast, local areas in Nigeria, eastern Gabon, many parts of DRC, Angola, local areas in Kenya, and southern Somalia had below-average rainfall.

8. Recent Rainfall Evolution Daily evolution of rainfall over the last 90 days at selected places reflects that seasonal total rainfall remained below-average over parts of Uganda (top panel-right). Moderate to heavy rainfall sustained moisture surpluses over parts of Botswana (bottom right), whereas it helped to erode some of the accumulated moisture deficits over parts of Angola (bottom left)

9. Atmospheric Circulation:Last 7 Days The 850Pa wind anomalies (left panel) featured dry northeasterly winds across central Africa region, which may contributed to the observed rainfall deficits in the region.

10. NCEP GEFS Model ForecastsNon-Bias Corrected Probability of precipitation exceedance Week-1: Valid 25 – 31 March 2014Week-2: Valid 01 – 07 March 2014 For week-1 (left panel) and week-2 (right panel), there is an increased chance for rainfall to exceed 50 mm over parts of Angola, eastern DRC, much of Tanzania, and portions of Ethiopia.

11. Experimental Week-1 Precipitation Outlooks • There is an increased chance for below-average rainfall over much of Congo Brazzaville, DRC, southern Angola, and portions of CAR: Anomalous lower-level northeasterly flow with its associated divergence is expected to suppress rainfall. Confidence: Moderate • There is an increased chance for above-average rainfall over southern Ethiopia and portions of Kenya: Interaction between mid-latitude and tropical systems across the Horn of Africa is expected to enhance rainfall in the region. Confidence: Moderate • There is an increased chance for above-average rainfall over eastern DRC, Rwanda, Burundi, Tanzania, northern Malawi, and portions of Kenya and Mozambique, the Comoros Islands, and northwestern Madagascar: Anomalous lower-level westerly flow across the Congo Basin coupled with cyclonic circulation near the Mozambique Channel is expected to enhance rainfall in the region.. Confidence: Moderate • There is an increased chance for below-average rainfall over portions of Southeast Africa: Anomalous lower-level divergence coupled with upper-level anti-cyclonic flow is expected to suppress rainfall in the region. Confidence: Moderate Mar 25 – Mar 31, 2014

12. Experimental Week-2 Precipitation Outlooks Apr 01 – Apr 07, 2014 • There is an increased chance for below-average rainfall over much of Congo Brazzaville and western DRC: Anomalous lower-level northeasterly flow with its associated divergence is expected to suppress rainfall in the region. Confidence: Moderate • There is an increased chance for above-average rainfall over much of Tanzania and the neighboring areas of eastern DRC, Rwanda, Burundi, northern Zambia, northern Mozambique, and northern Malawi: Anomalous lower-level westerly flow across the Congo Basin with its associated convergence is likely to enhance rainfall in the region. Confidence: Moderate

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