Weekly Introduction:
Update of El Niño:
Synopsis: ENSO-neutral conditions are expected during the next 3-6 months. Sea surface temperature (SST) anomalies increased throughout the eastern equatorial Pacific during June. By the end of the month, positive equatorial SST anomalies were observed in most areas between Indonesia and 90°W, while negative anomalies persisted along the South American coast. The increase in SST anomalies in the eastern equatorial Pacific during June was reflected in an increase in the SST departures in the Niño 3 and Niño 3.4 regions. However, the overall pattern of tropical convection was near average. A majority of the statistical and coupled model forecasts indicate that SST anomalies will likely remain positive during the next 3-6 months, but still within the ENSO-neutral range.
This discussion is a consolidated effort of NOAA and its funded institutions.
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. This 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. The recent rainy season has helped to raise the water levels marginally, however a recent satellite pass indicates that the water level is still six 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. Scattered showers are possible across Equatorial Guinea, 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. Scattered showers are expected early in the period. Improvement will be very slight, if at all.
5. During the last few weeks of June and first few weeks of July, rainfall has been erratic and lighter than normal across the southern-most part of the Ethiopian Highlands and the southern foothills of the Ahmar Mountains. These erratic rains may result in crop stress across parts of central Oromiya and eastern SNNPR. However, some parts of the area have received adequate rainfall. Rain chances are expected to improve during the period. An increase in rainfall will benefit crops and pastures in the region.
6. After soaking rains during the first ten days of July, additional heavy rains are expected across central portions of the troubled Darfur region in Sudan and the adjacent Chadian prefectures of Ouaddai and Biltine. The heavy rains are expected to hamper overland travel in the region and disrupt the movement of humanitarian aid to IDP and refugee camps. In addition, the heavy rains may 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. Little, if any rain has fallen across east-central parts of Cote D’Ivoire and southwestern Ghana over the past few weeks. The dry spell has stressed crops in the area. Scattered showers are expected across the region, which may ease short term moisture deficits and crop stress.
8. Abundant rains have fallen across much of the western Ethiopian Highlands over the past several weeks. These rains have favored the growth and development of crops and pastures in the region while resulting in abundant water supplies. Seasonal rains will continue through the period. This will continue to favor crops and pasture lands. However, some of the rain may be very heavy. This may cause some localized flash flooding and crop damage in western Oromiya, eastern Beneshangul Gumuz and central Ahmara.
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.