Reference Number: DMCN Dekad  27/2004
TENDAY BULLETIN
DROUGHT MONITORING CENTRE, NAIROBI (DMCN)
10 DAY CLIMATOLOGICAL SUMMARY AND IMPACTS FOR DEKAD 27(21-30 SEPTEMBER) 2004 AND OUTLOOK FOR DEKAD 29(11 - 20 OCTOBER) 2004

PRODUCED IN COLLABORATION WITH WMO AND THE NATIONAL METEOROLOGICAL AND HYDROLOGICAL SERVICES (NMHSs) IN THE GREATER HORN OF AFRICA (GHA) COUNTRIES

1.0    Hot Spot


Introduction

During dekad 27 (21-30 September) rainfall activities are usually located over the southwestern parts of the northern sector and western parts of the equatorial sector. The conditions, which prevailed during dekad 27 (21-30 September) 2004, the associated impacts on various socio-economic sectors and the climate outlook for dekad 29 (11-20 October) 2004 are summarized in the sections and subsections that follow.

 3.0  Observed rainfall situation during dekad 27

The spatial patterns of the rainfall distribution during dekad 27 (21-30 September) 2004 are shown in Figure 2 while figure 3 shows the patterns of the drought severity index.

3.1 Northern sector

Significant rainfall was recorded in southern parts of the sector with southwestern Sudan recording amounts above 100mm. On the other hand isolated areas in western Ethiopia observed driest conditions on record for the dekad since 1961.

 3.2 Equatorial sector

The western parts of the sector recorded significant rainfall with parts of eastern Uganda as well as western Kenya recording rainfall amounts in excess of 100mm resulting to wettest conditions on record for the dekad since 1961.

3.3 Southern sector

The northwestern parts of the sector received rainfall amounts in the range 10 to 30mm. The rest of the sector continued to experience dry conditions as expected at this time of the year.

 4.0 Assessment of current rainfall performance

An assessment of rainfall performance for some selected stations in the Sub-region is shown in figure 4.  Much of the equatorial and northern sectors have continued to record cumulative rainfall deficits.

5.0 Impacts on Socio-economic Sectors

The socio-economic impacts of the observed rainfall conditions over parts of the sub-region during the dekad including the vegetation conditions are described below.

5.1 Vegetation condition indicators

The Satellite imagery for dekad 27 (21-30 September) 2004 indicated much deterioration in vegetation conditions across eastern Ethiopia, Somalia, northern Sudan, eastern and northern Kenya, Tanzania, Djibouti and Eritrea. Improved vegetation conditions continued to be observed over western Ethiopia, portions of southwestern Kenya and southern Sudan.

5.2 Impacts of observed rainfall

The impacts of the rainfall conditions observed in the sub-region are highlighted below:

5.2.1 Positive impacts:

Parts of the northern and equatorial sectors that observed moderate rainfall had the following impacts:

5.2.2 Negative impacts:


6.0 Outlook

During dekad 29 (11-20 October) 2004 the St. Helena and Mascarene anticyclones and the associated high-pressure ridges are anticipated to weaken while the Sahara and Arabian high-pressure ridges are expected to intensify slightly. Consequently the zonal and meridional components of the ITCZ are likely to remain active over the southeastern parts of the northern sector and western parts of the sub-region respectively.

It is therefore expected that near to above normal rainfall is likely to be experienced over much of Burundi, Rwanda, Uganda, coastal and northwestern Tanzania, coastal, northeastern and western Kenya, southwestern Sudan, southern Djibouti, eastern Ethiopia as well as northern, central and southern coast of Somalia. Eastern and central Sudan, western and central Ethiopia, northeastern Uganda, southern Somalia and much of Kenya are likely to experience near to below normal rainfall. Generally dry conditions are likely to prevail over the rest of the sub-region (see map).