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 04 February 2013 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 total rainfall exceeded 160mm over portions of northern Mozambique, the Comoros Islands, Madagascar, and local areas in Malawi. • Suppressed rainfall prevailed over much of Zambia, Zimbabwe, Botswana, Namibia and southern Mozambique. • Week-1 outlooks call for an increased chance for above-average rainfall over parts of South Africa, and much of Madagascar. In contrast, there is an increased chance for below-average rainfall over much of Tanzania and the neighboring areas of Mozambique and Malawi.

4. Rainfall Patterns: Last 7 Days During the past seven days, above average rainfall was observed over much of Congo, parts of DRC, Angola, Rwanda, Burundi, local areas in Uganda, many parts of Tanzania, Southwest Kenya, northern Mozambique, local areas in South Africa, and much of Madagascar. Local areas in Angola and DRC, portions of Namibia, Botswana, much of Zimbabwe, Zambia, southern Mozambique, and local areas in Madagascar received below average rainfall.

5. Rainfall Patterns: Last 30 Days During the past 30 days, below-average rainfall was observed over southern Gabon, southern Congo, much of Angola, Namibia, portions of DRC, southern Botswana, Namibia, portions of South Africa, southern Uganda, parts of Tanzania, local areas in Kenya, and many parts of Madagascar. In contrast, local areas in Nigeria, southern CAR, local areas in DRC and Angola, southern Zambia, northern Botswana, much of Zimbabwe and Mozambique, southern Tanzania, and local areas in Madagascar received above-average rainfall.

6. Rainfall Patterns: Last 90 Days During the past 90 days, local areas in Guinea, Sierra Leone, local areas in Ghana, Nigeria and Cameroon, northern Gabon, portions of DRC, local areas in Angola, portions of Zambia, Uganda, portions of Kenya, local areas in Tanzania, portions of Mozambique, local areas in Zimbabwe, northeastern South Africa, and local areas in Madagascar received above average rainfall. In contrast, rainfall was below-average over parts of Gabon and DRC, local areas in Angola, parts of Botswana, Namibia and South Africa, local areas in Kenya, Somalia and Tanzania, and much of Madagascar.

7. Rainfall Patterns: Last 180 Days During the past 180 days, rainfall was above-average over local areas in Senegal, southern Mauritania, parts of Mali, Guinea Bissau, Guinea, Sierra Leone, portions of Liberia, local areas in Cote d’Ivoire, parts of Burkina Faso, Ghana, portions of Nigeria, local areas in Niger, southern Chad, northern Cameroon, much of CAR, portions of Gabon and DRC, portions of Angola, South Sudan, Uganda, local areas in Kenya and Ethiopia, parts of Zambia, central and southern Mozambique, eastern South Africa and portions of Madagascar. Local areas in Cameroon, portions of DRC, local areas in Ethiopia, portions of Kenya, local areas in southern Somalia, local areas in Namibia, South Africa, and portions of Madagascar had below average rainfall.

8. Recent Rainfall Evolution Daily evolution of rainfall over the last 90 days at selected stations reflects the recent moderate to heavy rainfall that helped to erode some of the moisture deficits over parts of Tanzania, (bottom panel – left) and Madagascar (top panel-right). Seasonal rainfall showed a decreasing trend recently over portions of Zimbabwe (bottom panel right).

9. Atmospheric Circulation:Last 7 Days The 850hPa wind anomaly (left panel) featured anomalous southerly winds from the Indian Ocean across northern Mozambique and Tanzania, which may have contributed to the observed moderate to heavy rainfall in the region. The 200hPa wind anomaly (right panel) featured anomalous upper-level cyclonic flow near South Africa.

10. NCEP GEFS Model ForecastsNon-Bias Corrected Probability of precipitation exceedance Week-1: Valid 05– 11 February 2013Week-2: Valid 12 – 18 February 2013 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, Zambia, Malawi, Mozambique and Madagascar.

11. Experimental Week-1 Precipitation Outlooks 05 – 11 February 2013 • There is an increased chance for above-average rainfall over parts of South Africa: Lower level wind convergence is expected to enhance rainfall in the region. Confidence: Moderate • There is an increased chance for below-average rainfall over much of Tanzania and the neighboring areas of Mozambique and Malawi: The projected phase of the MJO is expected to suppress rainfall in the region. Confidence: Moderate • There is an increased chance for above-average rainfall over much of Madagascar: Anomalous lower level cyclonic circulation is expected to enhance rainfall in the region. Confidence: Moderate

12. Experimental Week-2 Precipitation Outlooks 12 - 18 February 2013 • There is an increased chance for above-average rainfall over western Zambia, and the neighboring areas of Angola and Zimbabwe: Anomalous easterly winds from the Indian Ocean, with their associated convergence are expected to enhance rainfall in the region. Confidence: Moderate • There is an increased chance for below-average rainfall over Northeast South Africa and the neighboring areas of Southeast Botswana, northern Zimbabwe and southern Mozambique: Combination of anomalous lower level anti-cyclonic flow and upper level cyclonic circulation is expected to suppress rainfall in the region. Confidence: Moderate • There is an increased chance for above-average rainfall over the much of Madagascar: Anomalous lower level cyclonic circulation is expected to enhance rainfall in the region. Confidence: Moderate

13. Summary During the past seven days, above average rainfall was observed over much of Congo, parts of DRC, Angola, Rwanda, Burundi, local areas in Uganda, many parts of Tanzania, Southwest Kenya, northern Mozambique, local areas in South Africa, and much of Madagascar. Local areas in Angola and DRC, portions of Namibia, Botswana, much of Zimbabwe, Zambia, southern Mozambique, and local areas in Madagascar received below average rainfall. During the past 30 days, below-average rainfall was observed over southern Gabon, southern Congo, much of Angola, Namibia, portions of DRC, southern Botswana, Namibia, portions of South Africa, southern Uganda, parts of Tanzania, local areas in Kenya, and many parts of Madagascar. In contrast, local areas in Nigeria, southern CAR, local areas in DRC and Angola, southern Zambia, northern Botswana, much of Zimbabwe and Mozambique, southern Tanzania, and local areas in Madagascar received above-average rainfall. During the past 90 days, local areas in Guinea, Sierra Leone, local areas in Ghana, Nigeria and Cameroon, northern Gabon, portions of DRC, local areas in Angola, portions of Zambia, Uganda, portions of Kenya, local areas in Tanzania, portions of Mozambique, local areas in Zimbabwe, northeastern South Africa, and local areas in Madagascar received above average rainfall. In contrast, rainfall was below-average over parts of Gabon and DRC, local areas in Angola, parts of Botswana, Namibia and South Africa, local areas in Kenya, Somalia and Tanzania, and much of Madagascar. Week-1 outlooks call for an increased chance for above-average rainfall over parts of South Africa, and much of Madagascar. In contrast, there is an increased chance for below-average rainfall over much of Tanzania and the neighboring areas of Mozambique and Malawi.