CONSENSUS CLIMATE OUTLOOK FOR JUNE TO SEPTEMBER
2004 RAINFALL SEASON OVER THE GREATER HORN OF AFRICA
Summary
The June to September period constitutes a major rainfall season over much of
the northern sector of Greater Horn of Africa (GHA) sub-region. The consensus
climate outlook for this period indicates that there is increased likelihood
of near to above normal rainfall over eastern Uganda, coastal and western parts
of Kenya, southern coast of Somalia, northern coast of Tanzania, southern Sudan,
northern and southwestern Ethiopia, Djibouti and eastern Eritrea. On the other
hand, probabilities of near to below normal rainfall favour much of Uganda,
northwestern Kenya, central and extreme southern Sudan, southern Eritrea, extreme
northwestern Somalia as well as western, central and eastern Ethiopia.
Methodology
The current state of the global climate system and its implications over the
GHA region was examined. Among the principal factors taken into account were
the evolution patterns of the Sea Surface Temperature (SST) anomalies over various
parts of the global Oceans, particularly over the Indian and Atlantic Oceans,
the Quasi-Biennial Oscillation (QBO), monsoons and upper level wind circulation.
These and other factors that affect the climate over the Greater Horn of Africa
were similarly assessed. The products from several other advanced climate centres
were also taken into consideration in the development of the consensus climate
outlook. The centres whose products were utilized include the National Oceanic
and Atmospheric Administration/National Centers for Environmental Prediction
(NOAA/NCEP), European Centre for Medium Range Weather Forecasts (ECMWF), United
Kingdom Meteorological Office and the International Research Institute for climate
prediction (IRI). The current status of seasonal to inter-annual climate modeling
allows prediction of spatial and temporal averages and may not fully account
for the physical and dynamical factors that influence regional and national
climate variability.
June to September 2004 climate Outlook
The consensus climate outlook for June to September 2004 indicates increased likelihood of near to above normal rainfall over parts of eastern Uganda, coastal and western Kenya, southern coast of Somalia, northern coast of Tanzania, southern Sudan, northern and southwestern Ethiopia, Djibouti and eastern Eritrea. On the other hand, probabilities of near to below normal rainfall favour much of Uganda, northwestern Kenya, central and extreme southern Sudan, southern Eritrea, extreme northwestern Somalia as well as western, central and eastern Ethiopia. Areas that have been assigned for climatology include northern Sudan, northern Eritrea, much of Somalia, Kenya, Tanzania, Rwanda and Burundi (See Figure 1).
Note:
This Outlook is only relevant to seasonal time scales and relatively large areas;
local and month-to-month variations may occur. Users are strongly advised to
contact the respective National Meteorological Services for interpretation of
this Outlook and for updates and additional guidance.
Figure 1: GHA Consensus Climate Outlook for June to September 2004