The African Monsoon Recent Evolution and Current Status

1. The African Monsoon Recent Evolution and Current Status Update prepared by Climate Prediction Center / NCEP 08 March 2010 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 • During the past seven days, moderate to heavy rains continued to soak western Zambia and southeastern Angola and may have resulted in flooding in local areas. Early seasonal rainfall increased moisture surpluses over parts of the Greater Horn of Africa. • Dry conditions over the past few days sustained moisture deficits in southern Zimbabwe.

4. Rainfall Patterns: Last 7 Days During the past seven days, torrential rains increased moisture surpluses over western Zambia and parts of southeastern Angola. Rainfall was also above average over portions of central Mozambique, northern Malawi, western Tanzania, and along the east coast of Madagascar. Early rains soaked much of the Greater Horn of Africa, including eastern Ethiopia, local areas in southern Somalia, parts of Kenya, and eastern Uganda. Rainfall was below average locally over portions of northern and southern Mozambique, southwestern Madagascar, coastal Angola, and the northern areas of DRC.

5. Rainfall Patterns: Last 30 Days During the past 30 days, rainfall was above average central Mozambique and much of Zambia. Rainfall was also above average over parts of the Greater Horn of Africa, including eastern Ethiopia, western Kenya, and much of Uganda. Heavy rains resulted in moisture surpluses over parts of DRC and portions of the Gulf of Guinea region. In contrast, rainfall was below average over Madagascar, northeastern South Africa, northeastern Namibia, and local areas along coastal central Africa.

6. Rainfall Patterns: Last 90 Days During the past 90 days, rainfall was above average over the northern areas of southern Africa, parts of central Africa, and the Greater Horn of Africa. Rainfall was below average over southern Madagascar.

7. Rainfall Patterns: Last 180 Days During the past 180 days, rainfall was above average over parts of the northern areas of southern Africa, parts of central Africa and the Greater Horn of Africa. Rainfall was below average over southern Madagascar.

8. Recent Rainfall Evolution Daily evolution of precipitation during the last 90 days at selected regions shows that moderate to heavy rains over the past week sustained moisture surpluses over western Zambia (lower panel – left). Recent rains helped reduce moisture deficits over southern Zimbabwe (lower panel – right). Steady rains over the past several weeks brought seasonal rainfall to near average amounts over central Mozambique (upper panel – right).

9. Atmospheric Circulation:Last 7 Days The 850 hPa wind anomaly (left panel) reflected easterly wind anomalies over the central Indian Ocean extending into eastern Africa. The 200 hPa wind anomaly (right panel) reflected an anomalous cyclonic/anticyclonic couplet over the southern hemisphere mid latitudes.

10. Experimental Week-1 Precipitation Outlooks Week-1 Outlook 9 – 15 March, 2010 1. There is an increased chance for above average precipitation over western parts of equatorial Africa, including western Angola. The convergence between anomalous westerly winds from the Atlantic Ocean and easterly winds from the Congo Air Boundary (CAB) area is expected to enhance rainfall in the region. Confidence: Moderate 2. There is an increased chance for above average rainfall over much of Madagascar, northern Mozambique and the adjacent areas of southern Malawi and southern Tanzania. The interaction between mid-latitude and tropical systems across the Mozambique Channel together with the anomalous cyclonic flow in the vicinity of Madagascar are expected to increase rainfall in the region. Confidence: Moderate

11. Experimental Week-2 Precipitation Outlooks Week-2 Outlook 16 – 22 March, 2010 No forecast – Climatology suggested.

12. Summary • During the past seven days, torrential rains increased moisture surpluses over western Zambia and parts of southeastern Angola. Rainfall was also above average over portions of central Mozambique, northern Malawi, western Tanzania, and along the east coast of Madagascar. Early rains soaked much of the Greater Horn of Africa, including eastern Ethiopia, local areas in southern Somalia, parts of Kenya, and eastern Uganda. Rainfall was below average locally over portions of northern and southern Mozambique, southwestern Madagascar, coastal Angola, and the northern areas of DRC. • During the past 30 days, rainfall was above average central Mozambique and much of Zambia. Rainfall was also above average over parts of the Greater Horn of Africa, including eastern Ethiopia, western Kenya, and much of Uganda. Heavy rains resulted in moisture surpluses over parts of DRC and portions of the Gulf of Guinea region. In contrast, rainfall was below average over Madagascar, northeastern South Africa, northeastern Namibia, and local areas along coastal central Africa. • During the past 90 days, rainfall was above average over the northern areas of southern Africa, parts of central Africa, and the Greater Horn of Africa. Rainfall was below average over southern Madagascar. • For week-1, there is an increased chance for above average precipitation over western parts of equatorial Africa, including western Angola, as well as portions of eastern southern Africa.