2013 Summer Climate Outlook for the Greater Horn of Africa
June to August constitutes an important rainfall season over the northern sector and western parts of the equatorial sector of the Greater Horn of Africa. The regional consensus climate outlook indicates an increased likelihood of below normal to near normal rainfall over much of the region in the forthcoming season, according to a statement issued by the Greater Horn of Africa Climate Outlook Forum. Increased likelihood of near to above normal rainfall is indicated over central parts of the northern sector as well as the coastal and extreme western parts of the equatorial sector.
Factors which are expected to influence regional climate during June to August 2013 include sea surface temperatures, especially over the Indian and Atlantic Oceans. The regional climate outlook covers seasonal timescale and relatively large areas. National meteorological services will downscale the regional outlook to provide detailed forecasts at national levels.
A consensus statement from the 34th Greater Horn of Africa Climate Outlook Forum 29-30 May in Addis Ababa, Ethiopia, organized by the Intergovernmental Authority on Development’s Climate Prediction and Applications Centre (ICPAC) issued the following rainfall outlook for June to August 2013:
Zones I and V: Climatology. In most of these areas, it is not the main rainy season
Zones II, VI and VIII: Increased likelihood of near normal to above normal rainfall
Zones III, IV and VII Increased likelihood of below normal to near normal rainfall
WMO has been promoting the development of seasonal climate outlooks through Regional Climate Outlook Forums in many regions of the world as part of the Global Framework for Climate Services to increase the availability of user-friendly climate information for decision-makers and local communities alike. ICPAC is implementing the demonstration phase to seek designation as a WMO Regional Climate Centre.
The numbers for each zone indicate the probabilities of rainfall in each of the three categories, above-, near-, and below-normal. The top number indicates the probability of rainfall occurring in the above-normal category; the middle number is for near-normal and the bottom number for below-normal category. For example, in zone II, there is 35% probability of rainfall occurring in the above-normal category; 45% probability of rainfall occurring in the near-normal category; and 20% probability of rainfall occurring in the below-normal category. It is emphasised that boundaries between zones should be considered as transition areas.