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Weather Hazards Impacts Assessment for Africa: March 24 - 30, 2005


Weekly Introduction:

July-September 2005 Forecasts

Sahel


There is a low to moderate tilt in the odds favoring above normal rainfall across central Sahel in the areas including south central Mali, Burkina Faso, central and western Niger, and southern Chad. There is a slight tilt in the odds favoring below normal rainfall locally over western Mali, and portions of northern Chad.

Northern Horn of Africa


The outlook for Jul-Sep 2005 at four months lead calls for a slight to moderate tilt in the odds favoring below normal rainfall over portions of western Sudan, including the Darfur region, and over southern Ethiopia and central Somalia.

Gulf of Guinea Region


Climatology is expected across the region, except locally over eastern Guinea, where there is a slight tilt in the odds favoring above normal rainfall.

Locust Update

The report from the Food and Agriculture Organization (FAO) of the United Nations on the locust situation in western Africa was last updated on March 16 (http://www.fao.org/NEWS/GLOBAL/locusts/Locuhome.htm) indicating that the overall situation remains better than it was in 2004. Unless other indications are presented, this will be the last discussion of the locust situation. Additional details can be found at the USAID web site for Assistance for Emergency Locust/Grasshopper Abatement (AELGA) at http://www.aelga.net and the AGRHYMET site at http://www.agrhymet.ne.



Weather Hazards Assessment Graphic:

Weather Hazards Text Explanation:

1. The long and short rainy seasons of 2004 in much of eastern and central Kenya as well as parts of northern Tanzania produced rains that were well below normal. This has resulted in reduced moisture for the pastoral and bi-modal growing areas. The past several weeks, especially this past week, have brought significant rains to northern Tanzania and extreme southern Kenya. The coming period will likely bring continued rains to these areas.

2. Korahe, Gode, and Afder zones in Ethiopia's Somali region and adjacent parts of central Somalia received between 50 to 70 percent of normal rainfall in 2004. Seasonal dryness is expected to continue through the period.

3. Western Afar, eastern Tigray, eastern Ahmara and adjacent parts of Eritrea have seen significant improvement over the last few weeks. In 2004 the wet season was short and provided less than 50 percent of normal rainfall in some areas. However, recent rains have significantly increased soil moisture in the area. The coming week will likely bring continued rains, though not quite has heavy as they have been.

4. Central Darfur in Sudan and Biltine and Ouaddai in eastern Chad experienced a 2004 wet season that was short and contained erratic rainfall. This reduced soil moisture, degraded pastures and generally lowered water supplies throughout the region. The dryness has also aggravated the ongoing humanitarian crisis in the area.

5. Lake Victoria's water levels remain at 10 year lows. As of March 5th, water levels were 0.76 meters below the normal levels. This has reduced the flow into the Nile River. The below normal flow into the river is responsible for reduced hydroelectric power production in Uganda, causing power shortages, according to IRIN news. Rainfall totals of over 100mm fell on the lake during the previous week and more rain is expected during the coming week over the Lake Victoria Basin. While this will likely improve conditions for the lake, prolonged rainfall is needed to raise lake levels back to normal levels. The heaviest rains typically fall on the lake from April until May.

6. Several weeks of continuous rainfall over the western mountains of Angola have saturated the ground and swollen rivers. In Kwanza Norte alone 10,000 people have been left homeless. More rain is expected during the coming period and while it will likely be less intense, further flooding remains a concern.

7. The interior parts of Western Cape, South Africa have seen 25 to 60 percent of normal rainfall from April to September 2004, while closer to the coast normal conditions are being experienced. This extended drought has caused major shortages in both drinking and irrigation water resources and stressed pastures. Several reservoirs are reporting being at or near record lows. This past week brought less than 5mm of rain for most of the region, and the coming week will not bring any relief, with little or no rain expected.

8. Southern and central Mozambique, southern Malawi, southern and eastern Zimbabwe and adjacent parts of northeastern South Africa are well below normal for the 2004-2005 wet season. Deficits of 150 mm to 400 mm, or 60 to 25 percent and worse have continued to impact a wide area. This has significantly reduced soil moisture, stressed pastures, and lowered river levels causing water shortages. The driest areas are in the Gaza and Inhamambane provinces of Mozambique and Manicaland and Masvingo provinces in Zimbabwe. Lighter than normal rains during February and the first half of March have caused large areas of crops to wilt. Most of the area remained dry during the past week, although coastal Mozambique received some thunderstorms. This moisture however is too late to revive crops. The coming week will likely bring some scattered showers to the area.

9. A poorly timed dry spell in February has negatively impacted parts of Zimbabwe, central Mozambique, southern Zambia, central Malawi and extreme northeastern Namibia. Rains came to a halt for 3 to 5 weeks, this happened to occur during a critical period of crop development. This dry spell will reduce crop yields in affected areas. However, not all areas shown graphically are experiencing problems. Localized rains did manage to fall in some scattered spots, and yields in these areas can be expected to be better than surrounding. This occurred mainly in the orographically favored parts of Midlands and Mashonaland in Zimbabwe. Other areas, however, in negatively affected regions received anywhere from 25 to 75 percent of normal rain during February and similar conditions during March. This past week much of the region remained dry, with only scattered showers falling in some areas. The coming period will likely bring only light showers to much of the area, with central Malawi and southern Zambia receiving slightly higher totals.

AUTHOR: Eric J Wolvovsky