Kenya + 9 more

Weather Hazards Impacts Assessment for Africa: September 15 - 21, 2005


Weekly Introduction:
Update of El Niño:

Synopsis: ENSO-neutral conditions are expected during the next 3-6 months.

By early September, equatorial SSTs were near average in most areas between 180°W and the South American coast. The SST departures in the Niño 3, Niño 3.4, and Niño 1+2 regions were near zero, while positive departures (+0.4°C) persisted in the Niño 4 region. The general decrease in surface and subsurface temperature anomalies, observed during the last three months, has been accompanied by stronger-than-average easterly winds and near-average convection over the central equatorial Pacific.

The large spread of the most recent statistical and coupled model forecasts (weak La Niña to weak El Niño) indicates considerable uncertainty. However, current conditions and recent observed trends support a continuation of ENSO- neutral conditions for the next 3-6 months.

This discussion is a consolidated effort of NOAA and its funded institutions.

Locust Update:

The FAO on September 9 provided the following update- "The Desert Locust situation is generally calm in the summer breeding areas in the Sahel in West Africa. Despite unusually good rainfall and ecological conditions, only isolated adults have been detected by intensive surveys in Mauritania, Mali and Niger."

http://www.fao.org/ag/locusts/en/info/info/index.html


Weather Hazards Text Explanation:

1. In Kenya and southern Somalia, dry and localized drought conditions continue to reduce water resources and degrade pastures. During the March -- May wet season precipitation totals were low as a result of erratic rains. The previous period saw continued rains in western Kenya, however rainfall within the negatively impacted area will not begin to until October.

2. Significant rains continued to fall on Lake Victoria. Up to and exceeding 30 mm of rain fell on the lake itself during the past week. As of August 30th satellites measured the lake at 85 mm below normal. The low lake levels have caused a reduction in hydroelectric power generation in Uganda. It is unclear what other consequences this may have in the future. The coming week will likely see continued precipitation over Lake Victoria.

3. Light rains have moved back into Gabon, however more moisture is needed to recharge degraded pastures. An early end of the rainy season is responsible for the current conditions in Gabon. The coming week will bring continued light rains, potentially slightly heavier than last weeks precipitation. Steady precipitation normally begins this time of year with heavier totals arriving in October.

4. Much of Mozambique, southern Malawi, eastern Zimbabwe and extreme northeastern South Africa, continue to suffer from low drinking water, degraded pasture and a general lack of available water. This is the result of an erratic and abbreviated 2004-2005 wet season. The next chance for recovery is when the rains return in late October or early November.

5. Saturated soils around Bangui, Central African Republic continue to pose the threat of more flooding. While there has been no flooding in the area during the past week, more than 50 mm of rain fell and similar totals are expected during the coming week. The continued rainfall is preventing the Mbali, Mpoko, and Pama Rivers from returning to normal levels and all three pose a risk of localized flooding.

6. Seasonal rainfall in Darfur, Sudan, and adjacent portions of Chad, is coming to an end as the ITCZ continues to slip further to the south. Even so, rainfall in the area will continue to hamper the humanitarian relief efforts in the area by making travel by road nearly impossible. Conditions have continued to improve in the northern areas as the rains retreat southward. As much as 20 mm of rain fell in the area, with isolated locations receiving around 50 mm of precipitation. Rainfall totals will continue to drop over the next few weeks.

7. In Liberia, and central portions of Ivory Coast there are conflicting reports of current conditions. It is possible, that below normal precipitation has caused some short term dryness in the area. It should also be noted that this area does receive in excess of 3 meters of rain annually and the possible deficits are on the order of less than 20% of this regions' annual total. If these deficits are having an impact, the missing rain could be easily made up in the coming weeks.