1. The African Monsoon Recent Evolution and Current Status Include Week-1 and Week-2 Outlooks Update prepared by Climate Prediction Center / NCEP 14 May 2012 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 Rainfall was heavy across portions of Central and East African countries, with the heaviest weekly total(>120mm) occurring over local areas in Congo, DRC, South Sudan Republic, and in the Vicinity of Lake Victoria. Week-1 outlooks call for an increased chance for above average rainfall across coastal Gulf of Guinea, portions of central African countries, the Lake Victoria region, and over portions of Somalia. Below average rainfall is expected across portions of South Sudan Republic.

4. Rainfall Patterns: Last 7 Days During the past seven days, local areas in Guinea, Burkina Faso and Ghana, northern Togo, northern Benin, parts of northern Nigeria, portions of Cameroon, southern Chad, local areas in Gabon, much of Congo and DRC, South Sudan Republic, western Ethiopia, portions of Uganda, western Kenya and coastal Tanzania received above average rainfall. Below average rainfall was observed, across portions of Burkina Faso, Ghana, Nigeria, Cameroon, and parts of CAR.

5. Rainfall Patterns: Last 30 Days During the past 30 days, below average rainfall was observed over eastern Liberia, much of Cote d’Ivoire, Ghana, southern Togo and Benin, portions of Nigeria, Cameroon, Equatorial Guinea, Gabon, Congo, DRC, and CAR, northern Angola, eastern Kenya, southwestern Somalia, portions of Sudan, and northern Ethiopia. Local areas in Guinea, northern Benin, southern Cameroon, local areas in Gabon, portions of Congo and DRC, much of Uganda, western Kenya, northern Tanzania, South Sudan Republic, portions of Ethiopia and Somalia, and northern Madagascar had above average rainfall.

6. Rainfall Patterns: Last 90 Days During the past 90 days, below average rainfall was observed across coastal Gulf of Guinea, portions of Nigeria and Cameroon, coastal Congo, portions of Angola and CAR, many parts of DRC, portions of Ethiopia and Uganda, eastern Kenya, portions of southern Somalia, southern and western Tanzania, Zambia, Botswana, Zimbabwe, portions of South Africa and Mozambique, Lesotho, Swaziland, and local areas in Madagascar. Equatorial Guinea, Gabon, southern Angola, local areas in Zimbabwe and Zambia, and much of Madagascar had above average rainfall.

7. Rainfall Patterns: Last 180 Days During the past 180 days, rainfall was above average over local areas in Congo, western Kenya, many parts of Tanzania, southern and eastern Angola, northern Namibia, northern Mozambique, and portions of Madagascar. In contrast, moisture deficits were observed over parts of Liberia, Cote d’Ivoire and Ghana, southeastern Nigeria, southwestern Cameroon, Gabon, Congo, local areas in Ethiopia, many parts of DRC, western and northern Angola, southern Zambia, portions of Botswana, Zimbabwe, central and southern Mozambique, South Africa, and portions of Madagascar.

8. Recent Rainfall Evolution Daily evolution of rainfall over the last 90 days at selected stations reflects that moderate to heavy rains sustained moisture surpluses over western Kenya(bottom panel – left). In contrast, rainfall remained below average across eastern Kenya(bottom panel right) and parts of southern Somalia (top panel – right).

9. Atmospheric Circulation: Last 7 Days The 850hPa wind anomaly (left panel) featured convergence between anomalous easterly and westerly winds across Central African region, which may have contributed to the observed moderate to heavy rainfall in the region. The 200hpa wind anomaly (right panel) featured upper-level easterly anomaly across Southern Africa Countries.

10. NCEP GEFS Model Forecasts Non-Bias Corrected Probability of precipitation exceedance Week-1: Valid 15 – 21 May 2012 For week-1, there is an increased chance for rainfall to exceed 50 mm across coastal Gulf of Guinea, Central Africa and the Lake Victoria Regions.

11. Week-1 Outlook 15 – 21 May 2012 Experimental Week-1 Precipitation Outlooks 1.There is an increased chance for above-average rainfall over Cote d’Ivoire, Ghana, southern Togo, southern Benin, coastal Nigeria, Cameroon, Equatorial Guinea, Gabon, Congo, and western DRC: Stronger than normal westerly winds, and the projected phase of the MJO are expected to enhance rainfall in the region. Confidence: Moderate 2.There is an increased chance for below-average rainfall over South Sudan Republic: Anomalous low- level divergence is expected to suppress rainfall in the region. Confidence: Moderate 3.There is an increased chance for above-average rainfall over central Somalia: Stronger than normal moist northeasterly flow is expected to enhance rainfall in the region. Confidence: Moderate

12. Experimental Week-2 Precipitation Outlooks Week-2 Outlook 22 – 28 May 2012 1.There is an increased chance for above-average rainfall over northern DRC and the neighboring areas of CAR and South Sudan Republic: The projected phase of the MJO is expected to enhance rainfall in the region. Confidence: Moderate

13. Summary During the past seven days, local areas in Guinea, Burkina Faso and Ghana, northern Togo, northern Benin, parts of northern Nigeria, portions of Cameroon, southern Chad, local areas in Gabon, much of Congo and DRC, South Sudan Republic, western Ethiopia, portions of Uganda, western Kenya and coastal Tanzania received above average rainfall. Below average rainfall was observed, across portions of Burkina Faso, Ghana, Nigeria, Cameroon, and parts of CAR During the past 30 days, below average rainfall was observed over eastern Liberia, much of Cote d’Ivoire, Ghana, southern Togo and Benin, portions of Nigeria, Cameroon, Equatorial Guinea, Gabon, Congo, DRC, and CAR, northern Angola, eastern Kenya, southwestern Somalia, portions of Sudan, and northern Ethiopia. Local areas in Guinea, northern Benin, southern Cameroon, local areas in Gabon, portions of Congo and DRC, much of Uganda, western Kenya, northern Tanzania, South Sudan Republic, portions of Ethiopia and Somalia, and northern Madagascar had above average rainfall. During the past 90 days, below average rainfall was observed across coastal Gulf of Guinea, portions of Nigeria and Cameroon, coastal Congo, portions of Angola and CAR, many parts of DRC, portions of Ethiopia and Uganda, eastern Kenya, portions of southern Somalia, southern and western Tanzania, Zambia, Botswana, Zimbabwe, portions of South Africa and Mozambique, Lesotho, Swaziland, and local areas in Madagascar. Equatorial Guinea, Gabon, southern Angola, local areas in Zimbabwe and Zambia, and much of Madagascar had above average rainfall. Week-1 outlooks call for an increased chance for above average rainfall across coastal Gulf of Guinea, portions of central African countries, the Lake Victoria region, and over portions of Somalia. Below average rainfall is expected across portions of South Sudan Republic.