WEEKLY WEATHER HAZARDS ASSESSMENT STATEMENT May 5, 2004 DISCUSSION: 1. Poor performance of the wet season rains over the past several years has resulted in a long term, multi-year drought across the Sool Plateau and the nearby Togdheer Region in northern Somalia. This season, however, has seen above normal rainfall and overall good performance of the wet season rains. Satellite estimates show that rainfall was 25 to 50+ mm above normal for April 2004. Over the past week, 10 to 40 mm of rain fell across the region, resulting in additional improvement. However, long term deficits remain across the area. Some additional shower activity is possible early in the period. 2. Rainfall totals for 2003 were 40 to 65 percent of normal, resulting in long term moisture deficits. However, the long rains have so far been near to above normal which has resulted in improvement. Additional showers are expected during the period. The continuation of rainfall through early May will ease dryness concerns in the area and result in favorable conditions for pasture land improvement and water supply recharge. 3. Heavy rainfall in recent weeks has led to high water levels in the Jubba and Shebelle rivers in Somalia, with reports of flooding. Additional rainfall, some of which may be heavy, in the upper portions of the basins will continue the risk of flooding along these rivers during the period. 4. A very wet April was punctuated by a week of heavy rains across southwestern and portions of central Kenya, including the Nairobi area. Torrential rains (50-150 mm) resulted in widespread flooding problems in the area. Additional rainfall early in the period will exacerbate the flooding problems in the region. However, beneficial dryness is expected towards the end of the period which will help water levels to subside and soils to dry out. 5. Multi-seasonal drought has resulted in long term moisture deficits across interior sections of southeastern Kenya and northeastern Tanzania. Short term dryness has increased moisture deficits and has raised concerns over main season crops across most of the area. Dry conditions are expected during the period, which will increase stress on crops. 6. March-April rainfall has been about half of normal across portions of eastern Kenya, northeastern Tanzania and parts of southern Ethiopia. This has raised concerns over main season crops and pasture conditions. Scattered showers are possible in southern Ethiopia and extreme northeastern Kenya, while dry conditions are expected over southeastern Kenya and northeastern Tanzania. 7. Satellite estimates indicate that 75 to 150 mm of rain fell over northern S.N.N.P.R.S. and central Oromiya in the southern Ethiopian highlands during the past week. Additional daily showers and thunderstorms are expected over the area. Some of the rain may be heavy, especially early in the period. Therefore, the potential for flooding exists over the region. 8. Above normal rainfall during the 2003-04 season over the upper Zambezi basin has resulted invery high river levels and flooding problems along the upper Zambezi and its tributaries, especially in eastern Caprivi Strip. The dry season has set in across the region, however river levels remain high and flooding is a concern. Over the next few weeks, the river levels will subside and the risk of flooding will diminish. 9. Heavy rains over the past few weeks has resulted in high antecedent moisture levels along the Nigeria-Cameroon border. Additional rainfall may result in some flooding, especially early in the period. Torrential rains over central Nigeria may have resulted in flooding problems. Additional rains may aggravate these flooding problems. 10. TC 23S has developed over the central Indian Ocean near Diego Garcia, about 3000 km off the east coast of Madagascar. The system is not of immediate concern to Africa or Madagascar,but should be monitored. As of Wednesday, May 5 the maximum sustained winds were 35 knots. AUTHOR: Chester V. Schmitt