Angola + 5 more

Statement from the sixth Southern Africa regional climate outlook forum (SARCOF-6)


CLIMATE OUTLOOK (October 2002 - March 2003)

1.1 SUMMARY

The northern part of the SADC region (Democratic Republic of Congo, Tanzania, much of Angola, northern Zambia, northern Mozambique and southern Malawi) and the Island States are expected to receive normal to above normal rainfall for the period October to December 2002 while the rest of the region is likely to experience normal to below normal rainfall. During the period January to March 2003, there are high probabilities of normal conditions across much of southern Africa. However, there is a chance of rainfall sliding into the below normal category over the southern part of the region (Botswana, southern Zambia, southern Malawi, central and southern Mozambique, southern Namibia, much of South Africa, Zimbabwe and Swaziland), during the same period January to March 2003.

1.2 THE SIXTH CLIMATE OUTLOOK FORUM

The sixth Southern Africa Regional Climate Outlook Forum was held from 4 to 6 September 2002 to look at the prospects for the 2002/2003-rainfall season. This Outlook covers a period from October 2002 to March 2003. All the SADC countries within the region were represented as well as other scientists from cooperating international institutions.

This Outlook is relevant only 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.

The meeting reviewed the state of the global climate system and its implications for this region. Principal factors taken into account were sea-surface temperatures in the Pacific, Indian and Atlantic Oceans. In general, positive sea-surface temperature anomalies in the equatorial Pacific Ocean (El Nino) have been associated with below-normal rainfall conditions over much of the southern part of the subcontinent, particularly during the second half of the season. The current El Nino is still weak and developing as such the magnitude of its impacts on rainfall is unclear at this stage. The Indian and the Atlantic Ocean sea-surface temperature anomalies and the associated atmospheric circulation can significantly modulate the signal from the equatorial Pacific.

1.3 METHODOLOGY

The current status of seasonal-to-inter-annual forecasting allows prediction of spatial and temporal averages, and may not fully account for all factors that influence regional and national climate variability.

The experts established tercile probability distributions to indicate the likelihood of above-normal, normal to below-normal rainfall for each area (see Maps A and B). Above-normal rainfall is defined as within the wettest third of recorded rainfall amounts in each region; below-normal is defined as within the driest third of rainfall amounts; normal is the third centred on the climatological median.

1.4 OUTLOOK

October to March constitutes an important rainfall season over most of southern Africa. The outlook presented here is divided into two main periods, namely October to December (OND) 2002 and January to March (JFM) 2003.

October- December 2002

Zone I: DRC, much of Angola, northern Zambia, southern Malawi, Tanzania, northern Mozambique.

Likelihood of normal to above normal Rainfall

Zone II: Northern Zimbabwe, central and southern Mozambique, eastern Swaziland and the north-eastern tip of South Africa.

Likelihood of normal to above normal rainfall

Zone III: Much of Namibia, Botswana, southern and western Zambia, northern half of Malawi, southern Zimbabwe, northern and eastern South Africa, western Swaziland.

Likelihood of normal to below normal rainfall

Zone IV: Southern half of South Africa and Lesotho.

Likelihood of normal to above normal rainfall

Zone V: Mauritius.

Normal to above normal rainfall

Zone VI: Seychelles

Normal to above normal rainfall

Zone VII: Coastal Angola and northwestern Namibia.

January - March 2003

Zone I: Northern DRC.

Below normal to normal rainfall

Zone II: Tanzania, central and southern DRC, much of Angola, northern half of Zambia, northern half of Malawi, northern half of Mozambique, northern half of Namibia.

Normal to above normal rainfall

Zone III: Southern Zambia, southern Malawi, Zimbabwe, Botswana, southern Namibia, much of South Africa, Swaziland, central and southern Mozambique, Lesotho.

Normal to below normal rainfall

Zone IV: Mauritius.

Normal to above normal rainfall

Zone V: Seychelles.

Normal to above normal rainfall

Zone VI: Coastal areas of Angola and Namibia.

MAP CAPTION

The numbers for each region indicate the probabilities of rainfall in each of the three categories, below-normal, normal and above-normal. The top number indicates the probability of rainfall occurring in the above-normal category, the middle number is for normal and the bottom number is for below-normal. For example in the case of Mauritius for October-December 2002, there is a 45% probability of rainfall occurring in the above-normal category (i.e. within the range of the wettest third of recorded precipitation totals); a 35% probability in the normal category; and 20% probability in the below-normal category. It is emphasized that boundaries between regions should be considered as transition zones. Forecast information is provided only for countries that comprise the Southern Africa Development Community (SADC) region.

1.5 CONTRIBUTORS

The sixth Southern Africa Regional Climate Outlook Forum for the SADC region was organized jointly by the SADC-Drought Monitoring Centre, Harare (SADC-DMC), World Meteorological Organization (WMO), United Nation Environmental Programme (UNEP), Zimbabwe Meteorological Services and the International Research Institute for Climate Prediction (IRI), funded by the United States Agency for International Development (USAID), National Oceanic Atmospheric Administration/Office of Global Programmes and the Kingdom of Belgium.

Scientific contributors included representatives from Meteorological Services of fourteen SADC countries which are: Angola, Botswana, Democratic Republic of Congo, Lesotho, Malawi, Mauritius, Mozambique, Namibia, Seychelles, South Africa, Swaziland, Tanzania, Zambia and Zimbabwe. In addition there were contributors from International Research Institute for Climate Prediction, University of Cape Town, Drought Monitoring Centre-Nairobi and WMO. Additional inputs were also from the European Centre for Medium Range Weather Forecast and the United Kingdom Meteorological Office and other institutes.