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Weather Hazards Impacts Assessment for Africa: July 28 - August 3, 2005

News and Press Release
Originally published

Weekly Introduction:

Update of Seasonal Outlooks at Four-Months Lead:

November 2005 - January 2006 Forecast: Southern Africa;

There is a slight tilt in the odds favoring below normal rainfall locally over northern Mozambique. There is a slight tilt in the odds favoring above average rainfall over northwestern Angola.

Desert Locust situation deteriorates in Chad

The FAO bulletin of July 21 indicates that hopper bands have formed from recent hatching in eastern Chad and in adjacent areas of western and northern Darfur, Sudan. The extent of the populations is not well known because of the difficulty to access infested areas. This, and widespread rains that recently fell, could lead to the development of a local outbreak.

Weather Hazards Assessment Graphic:

Weather Hazards Text Explanation:

1. Rainfall during the March -- May 2005 rainy season was well below normal across southern Somalia, eastern Kenya and some parts of interior northeastern Tanzania. Rainfall totals for the period were only 40 to 70 percent of the long term average. This has resulted in deficits that range from 50 mm in some of the arid lowlands to over 400 mm in the mountains of southern Kenya. The lack of rainfall has likely reduced water supplies, degraded pastures, reduced crop production and resulted in crop failures. Along the north Kenya coast and far southern Somalia coast, heavy rains have managed to break the drought. However, conditions remain dry across the interior. Showers are possible along the coast during the period. Dry conditions are expected to persist away from the coast.

2. Below normal rainfall and above normal temperatures in recent years has lead to a decline in the water level on Lake Victoria. During late 2004 and early 2005, Lake Victoria’s water levels were more than three quarters of a meter below normal. This is the lowest the lake has been in over ten years. The low water levels reduced inflow to the Nile River and reduced hydroelectric power generation in southern Uganda. A recent satellite estimate of the lake’s level indicates that it is still about seven tenths of a meter below normal. As a result, reduced inflow into the Nile and the potential for reduced hydroelectric power generation will continue for the foreseeable future.

3. The rainy season ended 4 to 6 weeks early across much of Gabon and Equatorial Guinea. The early end to the rains resulted in moisture deficits of 150 to 400 mm and may have stressed crops that were not yet fully developed in May and early June. Showers are possible across Equatorial Guinea and far northern Gabon, however most of the region is expected to remain dry during the period. The rainy season typically begins in September across this part of Africa, with the heaviest rains of the year usually falling during the month of October.

4. Poor rainfall during the 2004-05 rainy season has resulted in the development of severe drought across southern Malawi, eastern Zimbabwe, a large portion of Mozambique and the northeastern corner of South Africa. Rainfall amounts for the season, which runs from November to April, were only 40 to 70 percent of normal. The moisture deficits of 200 to 600+ mm caused crop production losses, crop failures, degraded pastures and reduced water supplies. Except for some light rain along the Mozambique coast, seasonably dry conditions are expected during the period across southeastern Africa.

5. During the last few weeks of June and first few weeks of July, rainfall has been erratic and lighter than normal across the southwestern-most part of the Ethiopian Highlands and far southeastern Sudan. These erratic rains may result in crop stress across the area.

6. Periods of heavy rain are expected across central portions of Darfur, as well as Ouaddai and Biltine prefectures in Chad. The heavy rains will hamper overland travel in the region and disrupt the movement of humanitarian aid, fuel and supplies to IDP and refugee camps. In addition, the heavy rains will result in areas of standing water which raise concerns over sanitation and the spread of water/vector borne disease in the vicinity of the camps. The occurrence of heavy rain will also add to the overall stress and misery of those in the camps. However, the abundant rainfall will be beneficial to local farmers, pastures and will increase water supplies in the region.

7. Recent heavy rains in the mountains of western Ethiopia has swollen the Blue Nile and its tributaries. Additional heavy rain is expected during the period. As a result, flooding along the Blue Nile and its tributaries is possible in western Ethiopia and eastern Sudan. Further north, rain has been increasing. The situation will have to be monitored for possible flooding in some of the washes in western Eritrea, western Tigray and Kassala.

8. An early onset to the mini dry season in early July has resulted in a pocket of dryness in southwestern Ghana. Neighboring areas received some beneficial rainfall. However parts of southwestern Ghana have missed out. The short term dryness may have resulted in stress to crops that were not yet at maturity. Widespread crop failures, however, are not expected.

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