Outlook for Southern Africa’s climate: key findings from SARCOF-29

The Twenty-Ninth Southern Africa Regional Climate Outlook Forum (SARCOF-29) was held from August 26 to 28, 2024, in Harare. This forum brought together climate experts from various Southern African Development Community (SADC) National Meteorological and Hydrological Services (NMHSs) and the SADC Climate Services Centre (CSC) to assess and forecast climate patterns for the upcoming 2024/2025 rainfall season.

Rainfall forecast

The outlook indicates a mixed forecast for the SADC region regarding rainfall:

• October to December 2024 (OND): Most of the SADC region is expected to receive normal to above-normal rainfall. Notably, Mauritius and central Madagascar are included in this pattern. Conversely, the north-western part of the Democratic Republic of Congo (DRC) is expected to experience above-normal rainfall, while the remainder of the region, including the island states of Comoros and Seychelles, is anticipated to see normal to below-normal rainfall.
• January to March 2025 (JFM): Similar trends are projected, with normal to above-normal rainfall predicted in most areas, excluding the south-western fringes of South Africa and northern regions of DRC, Angola, Tanzania, northern Zambia, northern Malawi, northern Mozambique, and the central western tip of Madagascar, which may experience normal to below-normal rains.

Temperature outlook

The temperature outlook for the 2024/25 rainfall season (October 2024 to January 2025) indicates a high likelihood of above-normal temperatures in most parts of the SADC region, which may have implications for agriculture and water resources.

Methodology

The climate outlook was derived through a combination of statistical analysis, climate prediction models, and expert interpretations. The assessment considered oceanic and atmospheric factors, including the current neutral phase of the El Niño-Southern Oscillation (ENSO) and the Indian

Ocean Dipole (IOD), which is forecast to remain neutral throughout the season.

Three-monthly periods

The rainfall season has been subdivided into overlapping three-month periods:

• October-November-December (OND) 2024
• November-December-January (NDJ) 2025
• December-January-February (DJF) 2025

Rainfall zone classification

The forum’s findings categorise rainfall forecasts into zones, each with specific probabilities.

For October-November-December 2024 (Figure 1):

• Zone 1: Increased chances of above-normal rainfall (northern DRC).
• Zone 2: Increased chances of normal to below-normal rainfall (central DRC, northern fringes of Zambia, easternmost Malawi, Tanzania, most of Mozambique and Zimbabwe).
• and surrounding areas.
• Zone 3: Increased chances of normal to above-normal rainfall (southern DRC, Angola, most of Namibia, Zambia, Botswana, western fringes of Zimbabwe, Northeastern South Africa, southern Mozambique and Eswatini).
• Zone 4: Increased chances of normal to below-normal rainfall (southern Namibia, southern Botswana, most of South Africa and Lesotho.
• Zone 5: Increased chances of normal to below-normal rainfall (southern Madagascar).
• Zone 6: Increased chances of normal to above-normal rainfall (central Madagascar).
• Zone 7: Increased chances of normal to below-normal rainfall (northern Madagascar).
• Zone 8: Increased chances of normal to above-normal rainfall (Mauritius).
• Zone 9: Increased chances of normal to below-normal rainfall (Seychelles).
• Zone 10: Increased chances of normal to below-normal rainfall (Comoros).

For November-December 2024-January 2025 (Figure 2):

• Zone 1: Increased chances of above-normal rainfall (western DRC and northwestern Angola).
• Zone 2: Increased chances of normal to above-normal rainfall (central and southern Angola, easternmost DRC, northwestern Tanzania, Zambia, Zimbabwe, Botswana, most of Namibia, western Malawi, central to southern Mozambique, Eswatini and northeastern South Africa).
• and surrounding areas.
• Zone 3: Increased chances of normal to below-normal rainfall (central to southwestern Angola, western coastal Namibia, most of central South Africa and Lesotho).
• Zone 4: Increased chances of normal to below-normal rainfall (bulk of Tanzania, eastern Malawi and northern Mozambique).
• Zone 5: Increased chances of normal to below-normal rainfall (southern Madagascar).
• Zone 6: Increased chances of normal to above-normal rainfall (northern Madagascar).
• Zone 7: Increased chances of normal to above-normal rainfall (northern Mauritius).
• Zone 8: Increased chances of normal to below-normal rainfall (Seychelles).
• Zone 9: Increased chances of normal to below-normal rainfall (Comoros).

For December 2024-January-February 2025 (Figure 3):

• Zone 1: Increased chances of below-normal rainfall (northern fringes of Tanzania).
• Zone 2: Increased chances of below-normal rainfall (northern DRC).
• and surrounding areas.
• Zone 3: Increased chances of normal to below-normal rainfall (most of Tanzania, northeastern Mozambique, northern tip of Malawi, southernmost DRC and Angola).
• Zone 4: Increased chances of normal to above-normal rainfall (southeastern Angola, most of Namibia, Botswana, Zambia, Zimbabwe, Malawi, most of South Africa, Lesotho, Eswatini and most of Mozambique).
• Zone 5: Increased chances of normal to below-normal rainfall (southwestern Namibia and southwestern South Africa).
• Zone 6: Increased chances of normal to below-normal rainfall (southernmost Madagascar).
• Zone 7: Increased chances of normal to above-normal rainfall (most of Madagascar).
• Zone 8: Increased chances of normal to above-normal rainfall (Mauritius).
• Zone 9: Increased chances of normal to below-normal rainfall (Seychelles).
• Zone 10: Increased chances of normal to below-normal rainfall (Comoros).

Long-term rainfall trends

Historical data (1981-2010) shows increased rainfall averages moving from southwest to northeast across the SADC region. This pattern is consistent for the major rainfall seasons, with maxima exceeding 500 millimetres in areas like Malawi and Zambia.

The SARCOF-29 forum emphasises the importance of understanding regional climatic patterns, as they have significant implications for agriculture, water management, and disaster preparedness in Southern Africa. Users are strongly encouraged to engage with their National Meteorological and Hydrological Services for further interpretation and updates as the seasons progress.

This comprehensive article encapsulates the vital forecasts and findings from the SARCOF-29, providing a clear and informative overview for stakeholders interested in Southern Africa's climate outlook. The forecasted probabilities are broadly consistent with the known influence of La Niña on the regional climate.