Africa: Weather hazards assessment 28 Apr - 04 May 2005
Situation in Ethiopia
Given reports of continuing food stress, the outcome of the current rainy season is especially important this year. The early dry spell this year may postpone harvests and extend the current hunger season. However, rains appear to be returning to the area and we will continue to monitor the situation with respect to pasture viability and crop availability.
Update of Seasonal Outlooks at Four-Months Lead: Aug-Oct 2005 Forecasts
Gulf of Guinea Region
Climatology is expected across the region, except locally over western Guinea, where there is a slight tilt in the odds favoring above normal rainfall.
There is a low to moderate tilt in the odds favoring above normal across central Sahel in the areas including eastern Mali, Burkina Faso, central and western Niger, and central Chad. There is also a slight tilt in the odds favoring above normal rainfall locally over southwestern Mauritania. There is a slight tilt in the odds favoring below normal rainfall locally over southwestern Mali, eastern Senegal, and northern Chad.
Northern Horn of Africa
The outlook for Aug-Oct 2005 at four months lead calls for a slight tilt in the odds favoring below normal rainfall over portions of western Sudan, including the southern Darfur region, and over southwestern Ethiopia. There is also a slight tilt in the odds favoring below normal rainfall locally over central and northern Ethiopia.
Weather Hazards Assessment Graphic:
Weather Hazards Text Explanation:
1. Much of Kenya continues to suffer from below normal precipitation, while southern Somalia is currently experiencing a delayed start to the season. This past week many areas received no rain, and throughout the current season the rains have been erratic and light. This unsteady rain has slowly degraded pastures and reduced soil moisture, negatively impacting the pastoral and bi-modal areas. Precipitation in the south has been especially light with deficits as high as 200 mm. The coming week will likely bring some rain to the northern areas, while much lighter precipitation will fall to the south.
2. The rains in Ethiopia's Somali region have been good, despite a late start to the season. The delayed start of the rains has extended the hunger season and will delay any harvests. During the past week up to and exceeding 50 mm of rain fell helping to improve soil moisture after a dismal 2004 season in which 50 to 70 percent of normal rain fell. The rains are expected to continue through the next week.
3. An abbreviated and erratic wet season across Central Darfur, Sudan and Biltine and Ouaddai, Chad in 2004 reduced soil moisture, degraded pastures and lowered water supplies. The humanitarian crisis in the region has not been helped by the dry conditions. The next opportunity for relief will occur with the beginning of the wet season in July.
4. As of April 13th Lake Victoria's surface level was at a 10-year low of 0.73 m below normal. This has reduced water flowing into the Nile River, where Uganda produces hydroelectric power. As a result of the lowered flow in the Nile, power generation has been significantly reduced. Rain did fall on the lake during the past week with totals of up to and exceeding 20 mm. Similar conditions are expected next week.
5. Dry conditions continue across interior Western Cape in South Africa. From April to September of 2004 only 25 to 60 percent of normal precipitation fell during what is typically the wettest time of year. Closer to the coast normal conditions have prevailed. Recent rains have eased the dry conditions and have begun refilling regional reservoirs. However, soil moisture deficits continue to plague the region. Light rains are expected in the region over the next week.
6. Reduced soil moisture, stressed pastures, and lowered river levels across a wide area of southeastern Africa were caused by large rainfall deficits of 150 mm to 400 mm. Specifically, southern and central Mozambique, southern Malawi, southern and eastern Zimbabwe and adjacent parts of northeastern South Africa experienced widespread crop failures. Southern parts of Mozambique are the worst affected, especially Gaza and Inhamambane. Zimbabwe's Manicaland and Masvingo provinces are also experiencing severe conditions. Seasonably dry conditions have moved into the area and only light scattered showers are expected over the next week.
7. Zimbabwe, central Mozambique, southern Zambia, central Malawi and northeastern Namibia continue to suffer from a poorly timed dry spell that occurred from February into mid-March. The rains came to an abrupt halt for 3 to 5 weeks during a critical period of crop development. Some small pockets in orographically favorable locations in Midlands and Mashonaland, Zimbabwe escaped the dry spell as the rains continued to fall with minimal interruptions. However, the negatively affected regions far outnumber those spared. During February and March only 25 to 75 percent of normal rain fell. Dry conditions have moved into the area, although some light scattered showers may fall over the region.
8. Rain continues to improve conditions across Tigray, Afar, Amhara, SNNPR and Oromiya regions of Ethiopia. The halt in the rains in late March and early April may have caused some wilting of crops. The pause in the rains has extended the hunger season and will delay the harvesting of crops. However with the return of the rains, conditions continue to improve. Precipitation totals of up to and exceeding 75 mm fell in some areas during the past week and similar conditions are expected during the coming week.
9. The abundant rains in Ethiopia and parts of Somalia have filled rivers, and will likely cause flooding during the coming week along the Jubba and the Shabelle Rivers. Flooding has also been reported in and around Hargeisa in northern Somalia. Some tributaries of the Shabelle have already burst their banks and with continued rainfall, more flooding is likely.
10. Little to no rain has fallen in northern portions of Morocco since mid March. This combined with above normal temperatures has reduced soil moisture available for the winter wheat crop. Only a few sprinkles fell in isolated locations during the past week, and similar conditions are expected next week.
AUTHOR: Eric J Wolvovsky