CONSENSUS CLIMATE OUTLOOK FOR THE GREATER HORN OF AFRICA (GHA) JUNE TO AUGUST 2007 RAINFALL SEASON

SUMMARY

June to August constitutes an important rainfall season for the northern sector of the Greater Horn of Africa (GHA), as well as coastal and western parts of the equatorial sector. ICPAC consensus climate outlook for the June to August 2007 season indicates enhanced probabilities for near to above normal rainfall over Djibouti; southwestern Eritrea; northern, central and western Ethiopia; central and southern Sudan; Uganda; coastal and western Kenya; southern coast of Somalia and northern coast of Tanzania.

Cold temperatures, frosty and foggy conditions are likely to dominate most of the highlands over the equatorial and southern sectors.

Many parts of the equatorial sector have received poorly distributed rainfall during the March to May 2007 rainfall season. The June to August rainfall season is also dry over much of the equatorial sector. Further La Niña conditions have been projected to persist up to the end of the year. Drought stress that could prevail in the equatorial sector for most of the year should therefore be noted as the equatorial sector usually receives poorly distributed rainfall during the onset phase of La Niña events. A more comprehensive climate outlook for the September to December 2007 will be provided during COF 20 to be held at the end of August 2007.

METHODOLOGY

The state of the global climate system and its implications for the sub-region was reviewed to facilitate formulation of the June to August 2007 GHA climate outlook. Among the principal factors taken into account were the evolution patterns of the sea-surface temperature anomalies over various parts of the global Oceans including anomalous sea surface temperatures (SSTs) that have been observed over many parts of the global oceans, with special reference to the oceans surrounding Africa, the evolving La Niña conditions, and the dominant systems that control regional climate. Outputs from the advanced climate centres were also used in the development of the regional consensus climate outlook over GHA for June to August 2007. The centres whose products were utilised include ICPAC, University of Nairobi, the International Research Institute for climate and society (IRI); National Oceanic and Atmospheric Administration/National Centers for Environmental Prediction (NOAA/NCEP); Florida state University, European Centre for Medium Range Weather Forecasts (ECMWF) and the United Kingdom Meteorological Office.

OUTLOOK

June to August constitutes a major rainfall season over much of the northern sector as well as the coastal and western parts of the equatorial sector. The rainfall outlook for each zone within the sub-region is provided below.

June to August 2007 Consensus Climate Outlook for the Greater Horn of Africa

Zone I: Climatology is indicated over northern Sudan; northern and eastern Eritrea as well as northeastern Djibouti.

Zone II: Increased likelihood of near to above normal rainfall over much of Djibouti; northern, central and western Ethiopia; southwestern Eritrea; central and southern Sudan; Uganda and western Kenya.

Zone III: Climatology is indicated over much of Tanzania; Burundi; Rwanda; Kenya; Somalia; eastern and southern Ethiopia as well as extreme southwestern Uganda.

Zone VI: Enhanced probabilities for near to above normal rainfall over southern coast of Somalia; Kenyan coast and northern coast of Tanzania.

Note:

This outlook is relevant only for seasonal time scales and relatively large areas. Local and month-to-month variations may occur. The National weather services and the ICPAC provide regular update forecasts. The users are therefore strongly advised to keep in contact with their National Meteorological Services for interpretation of this outlook, finer details, updates and additional guidance.