* The rainfall season is generally predicted to start mid-November in southern Malawi districts
* Such as Mulanje, Thyolo, Chiradzulu, Blantyre, Phalombe, Zomba and Mchinji
* And spread to some districts during end November and early December
Maravi Express
The 2024/2025 season is expected to be wetter than the previous season with a high chance of normal to above normal rainfall amounts over most parts of the country.
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This is contained in a statement issued by the Department of Climate Change and Meteorological Services (DCCMS) after a seasonal forecast review held today at Sunbird Lilongwe Hotel, saying the “rainfall amounts across most areas of Malawi anticipated to be normal to below normal from the onset of October to December 2024.
“However, some areas in central region and along the northern Lakeshore may experience normal to above-normal rainfall.
Typically, the main rains begin in November, starting in the south and progressively moving northwards and pre-season rains, locally known as Chizimalupsya, frequently arrive before the main rainfall season begins.
The Department further says from January to March 2025, the public should expect total rainfall amounts to be generally above normal to normal across most areas.
The forecast review at Sunbird Lilongwe Hotel
Season Onset
The rainfall season is generally predicted to start mid-November in southern Malawi districts such as Mulanje, Thyolo, Chiradzulu, Blantyre, Phalombe, Zomba and Mchinji and spread to some districts during end November and early December.
The onset is expected to be slightly late roughly by two weeks mainly over some parts of the country such as Karonga, Kasungu and Chitipa, which is two weeks later than the previous 2023/2024 season, and the onset could reach mid to end December in some parts of these districts.
Season Cessation
Most areas of Malawi are expected to experience a normal to late cessation of rains, thus from early to mid-April. However, some parts of Kasungu, Machinga and Mchinji may see an early cessation of rain, possibly by a week or more.
Seasonal Length
The rainfall season is likely to be longer in most districts of southern Malawi compared to the previous 2023/2024 season.
The seasonal length is likely to be greater than 110 days in many districts, but attention is given to Machinga and Kasungu that may have shorter length by 10 days or more.
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Temperature
From October to December 2024, temperatures are anticipated to be higher than usual, raising the chances of heat waves during this time.
In contrast, from January to March 2025, most regions are expected to experience normal temperatures.
Impacts
The 2024/2025 season is expected to be generally wetter than the previous season. However, rainfall in November is likely to be reduced in most areas of the country which may have a negative effect on the season’s onset.
Despite some areas expecting an erratic onset, forecasts indicate that once the rainfall season establishes itself, the likelihood of experiencing a relatively good rainfall season will significantly increase.
This expected increase in rainfall could enhance agricultural productivity and improve water resources; nevertheless, it may also lead to significant rainfall extremes, raising the risk of flooding that might impact crop yields, properties, infrastructure and lives.
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Additionally, the forecast indicates that this season’s rainfall is likely to sustain the elevated water levels in Lake Malawi. This presents opportunities for various sectors including hydropower generation, water supply and irrigation.
However, elevated water levels could continue to pose significant challenges for communities along the lake and the Shire River.
Influential Rainfall Systems
The main drivers of rainfall in Malawi include the Inter-tropical Convergence Zone, Congo air mass, easterly waves, and tropical cyclones.
These systems are influenced by various factors, including mean sea level pressure, upper-level winds, and sea surface temperatures in the tropical Pacific, Indian, and Atlantic Oceans.
El Nino Southern Oscillation Projection
Global climate models indicate that weak La Niña conditions are expected to prevail during a considerable part of the 2024/2025 rainfall season.
La Niña is marked by the unusual cooling of waters in the Eastern-Central Equatorial Pacific Ocean and typically results in increased rainfall in southern Africa, potentially affecting southern Malawi as well.
Notable historical years that serve as analogues for the forthcoming 2024/2025 season are 1995/1996, 1998/1999, 2010/2011, and 2016/2017.
Application of the Forecast
This forecast is relevant for relatively large areas and seasonal time scales and therefore may not account for all factors that influence localized climate variability, such as daily and weekly variations.
To cater for localized climate variability and monthly variations, DCCMS has produced downscaled district forecasts. Furthermore, daily, five-day, weekly forecasts, ten-day agrometeorological bulletins and seasonal updates will continuously be provided throughout the season.
DCCMS will also issue warnings and advisories regarding potential extreme weather events that may occur during the season.
Users from various sectors, including agriculture, disaster management, energy, and water are encouraged to seek advice from the relevant Ministries to better apply this forecast in their respective fields.
Sub-season probabilistic forecast: October to December and January to March
In Map A, the yellow colour dominates and it indicates that the greater part of Malawi has 25% probability of rainfall amounts occurring in the above-normal category; a 40% probability in the normal category; and a 35% probability in the below-normal category, implying normal to below-normal total rainfall amounts are expected over most areas, with likelihood of above-normal over Central and Northern Lakeshore areas.
In Map B, the blue colour dominates which indicates a 40% probability of rainfall amounts occurring in the above-normal category; a 35% probability of rainfall amounts occurring in the normal category and a 25% probability in the below-normal category.
This implies above-normal to normal total rainfall amounts are expected over many areas.
“Stay informed, stay prepared, and stay safe during the upcoming rainfall season. Your safety and well-being are our top priorities,” concludes the statement.
For further information, the public is encouraged to contact: The Director of Climate Change and Meteorological Services, P.O. Box 1808, Blantyre; e-mail: metdept@metmalawi.gov.mw; website: www.metmalawi.gov.mw
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