Update of Seasonal Outlooks at Four-Months Lead: May – July 2006
There is a weak to moderate tilt in the odds favoring above normal rainfall locally over western Mauritania, west central Mali, northern Burkina Faso, and locally over western Niger. A slight to moderate tilt of the odds toward below normal rainfall exists locally over southwestern Mali and central Chad.
Northern Horn of Africa
Climatology is expected across most of the region, except locally over western Ethiopia, where there is a slight tilt in the odds favoring below normal rainfall.
Gulf of Guinea Region
The outlook for the Gulf if Guinea region rainfall at four months lead indicates a weak tilt in the odds favoring below normal rainfall over southeastern Cote d’Ivoire, the southeastern part of Ghana, the southern areas of Togo and Benin and the southwestern portion of Nigeria.
Weather Hazards Assessment Graphic:
Weather Hazards Text Explanation:
1. Several poor consecutive rainy seasons have resulted in the development of severe drought across much of eastern Kenya, southeastern Ethiopia and southern Somalia. The poor performance of this year’s March-May season and the failure of the October- December season have resulted in rainfall totals for the year 2005 that are only 20 to 50 percent of the long term mean, and annual rainfall deficits of 250 to 500 mm. This severe drought has resulted in crop failures, pasture degradation, water shortages and has threatened the overall food security situation in the region. Although an increase in shower activity due to the start of the wet season has resulted in some improvement across interior central Tanzania, the rest of the region remained dry. No relief is expected in the short term and long term drought will persist for at least the next 2-4 months.
2. Drier than normal conditions since October has resulted in drought across western Kenya, much of Tanzania and the Lake Victoria Basin. In the bimodal areas of southern Kenya, northwestern Kenya and northeastern Tanzania, the short rains have failed for the 2005 season. In the southern and eastern parts of the Lake Victoria Basin, rainfall since October 1 has totaled only 200 to 300 mm. This is only 45 to 70 percent of normal, and has caused crop and pasture stress. On Lake Victoria, passenger ships failed to find docking stations in some areas due to the shallow water levels in recent weeks. Although the dry conditions in and around the basin have contributed to the low water levels, other factors such as downstream dam releases, are playing a substantial role. Across Tanzania’s interior, widespread rainfall a few weeks ago signaled the start of the season. However, these rains did start 4 to 6 weeks late, and deficits stand at 50 to 150 mm. Therefore, more rain is needed. An early end to last year’s season has combined with this years’ late start to the season over the central Tanzania to result in the development of hydrological drought. The drought is resulting in serious problems in the Rufiji basin.
3. Seasonal rains across Djibouti and the surrounding area have been erratic and lighter than normal. This has resulted in pasture degradation and possible water shortages. Rainfall totals for 2005 are around half of the long term mean. Scattered showers occurred over the past few weeks across southern Djibouti, however little in the way of improvement was observed. The next chance for relief will be when the March-May rains set in.
4. Rainfall has been above normal across most of Namibia, Angola, Botswana, Zimbabwe and Zambia this season, with many areas reporting the largest season to date totals in several years. These abundant rains have led to good crop prospects. However, the abundant rains have saturated soils and resulted in some flooding. Heavy rains during the period may trigger flooding across northern Namibia, northwestern Botswana and far southern Angola during the period. Heavy rains may also trigger some localized flash flooding problems in southern Zambia and northern Zimbabwe.
5. Tropical Cyclone Boloeste has redeveloped in the Mozambique Channel and is expected to have an impact on Madagascar and the central Mozambique coast early in the period. Heavy downpours and gusty winds are possible along the central Mozambique coast. However, the system is expected to either pass over or very close to southwestern Madagascar. As a result, the potential for a period of torrential rain and strong winds exists. At the time of writing, it appears the system will have the greatest impact on southwestern Madagascar on February 3rd. Landslides, flooding, crop and infrastructure damage are all a possibility. By the 4th, the system is expected to be on its way out to sea.
AUTHOR: Chester V. Schmitt
Questions or comments about this product may be directed to Alvin.Miller@noaa.gov or 1-301-763-8000 x7552
FEWS NET is a USAID-funded activity whose purpose is to provide objective information about food security conditions. Its views are not necessarily reflective of those of USAID. The FEWS NET weather hazards assessment process and products include participation by FEWS NET field and home offices, NOAA-CPC, USGS, NASA, and a number of other national and regional organizations in the countries concerned.