TENDAY BULLETIN
IGAD CLIMATE PREDICTION AND APPLICATIONS CENTRE (ICPAC*)
10 DAY CLIMATOLOGICAL SUMMARY AND IMPACTS FOR DEKAD 17(1-10 JUNE) 2008 AND OUTLOOK FOR DEKAD 19(21 - 30 JUNE) 2008
THIS BULLETIN IS PRODUCED IN COLLABORATION WITH WMO AND THE NATIONAL METEOROLOGICAL AND HYDROLOGICAL SERVICES (NMHSs) IN THE GREATER HORN OF AFRICA (GHA) COUNTRIES
1.0 Highlights
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Rainfall intensified in the northern sector of the Greater Horn of Africa (GHA) during dekad 17 (11 - 20 June 2008.
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The northern sector of the GHA is likely to continue receiving heavy rainfall while coastal equatorial sector will experience decreased rainfall during dekad 19.
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The rainfall occurred during deakad 17 led to floods and outbreak of respiratory diseases over the coastal sector and cholera in parts of western Kenya.
2.0 Introduction
This bulletin provides a summary of the observed climate conditions during dekad 17 and the climate outlook for dekad 19 over the Greater Horn of Africa (GHA) sub-region. The potential impacts of the observed and expected regional climate conditions are also highlighted.
3.0 Observed rainfall situation during dekad 17(11 - 20 June) 2008
The spatial patterns of the observed rainfall and the rainfall stress severity index during dekad 17 over the GHA sub-region are shown in figures 1 and 2 respectively.
3.1 Northern sector
During dekad seventeen of the year 2008, the eastern and the northern parts of the northern sector received less than 10mm of rainfall, leading to dry conditions (fig.2.). Southwest and central parts received between 30mm to 100mm of rainfall leading to near normal to wet conditions.
3.2 Southern and Equatorial sectors
The coastal strip received between 50 to 100mm during Dekad seventeen leading to above normal rainfall while north western side of the equatorial sector received rainfall between 30mm to 50mm leading to near normal conditions (fig.2).Most of the southern and the eastern parts of the equatorial sector received less than 10mm of rainfall leading to generally dry conditions shown in figure 2.
Figure 1: Spatial distribution of observed rainfall during dekad 17 (11 - 20 June) 2008
Figure 2: Rainfall Stress Severity Index for Dekad 17 (11 - 20 June) 2008
4.0 Assessment of current rainfall performance
The cumulative dekadal rainfall is used to evaluate water stress over various parts of the GHA sub-region. The dekadal rainfall totals cumulated since January 2008 for selected stations indicate a reduction in rainfall over the southern and equatorial sector with a shift of rainfall to the northern sector (Figures 3a, 3b and 3c).
Figure 3a: Cumulative rainfall series for selected stations
Figure 3b: Cumulative rainfall series for selected stations
5.0 Climate outlook
The climate outlook for dekad 19 (1 - 10 July 2008) indicates that central and southern Sudan; western and parts of central Ethiopia; western Kenya; central and northern Uganda are likely to receive near to above normal rainfall. However, coastal Kenya, North coast of Tanzania and south coast of Somalia are expected to receive near to below normal rainfall. The rest of the GHA sub-region are likely to remain generally dry (Figure 4).
Figure 4: Climate outlook for dekad 19 (1 - 10 July) 2008
6.0 Impacts expected on vegetation and Socio-economic sectors
The socio-economic impacts associated with the vegetation conditions and observed rainfall conditions are highlighted below:
6.1 Vegetation condition indicators
The vegetation anomalies for dekad 17 (11-20 June 2008) indicates improved vegetation conditions over western equatorial, central and southern Sudan as well as western and central Ethiopia (Fig. 5).
Figure 5: NDVI anomalies between second and first Dekad of June 2008
6.2 Socio-economic impacts
The observed rainfall conditions over the GHA sub-region during the second dekad of June 2008 were associated with the following impacts:
• Improved agricultural production over the western and coastal equatorial sectors.
• Increased agricultural activities over parts of the northern sector.
• Floods over the coastal equatorial sector.
• Improved pasture and water conditions for livestock over parts of north eastern Kenya and Southern Somalia
• Outbreak of respiratory diseases over the Kenya coast due to increased moisture conditions
• Outbreak of cholera in parts of western Kenya.
6.3 Expected socio-economic impacts associated with Outlook
• Increased cases of weather related diseases such as malaria over the coastal and western Kenya
• Floods over parts of central and southern Sudan and western Ethiopia
• Reduced pasture conditions and water stress for livestock over Somalia, eastern Ethiopia and north eastern Kenya
