5 April 2024
Heavy rain is forecast from the weekend into early next week over central and southern parts of South Africa, with warnings of floods in some areas.
After a very dry 2024 to date, large parts of South Africa can expect heavy rain from Saturday onwards.
Summer rainfall region
On Saturday and Sunday, the rain will initially occur over North West, western parts of the Free State and eastern parts of the Northern Cape, before expanding to the eastern Free State and KwaZulu-Natal.
From Sunday to Wednesday 10 April, the rain may shift further south to the southern Free State, the Eastern Cape and the Garden Route, where heavy rain may fall.
“There is a warning that flooding may occur, especially in the Eastern Cape and adjacent areas. Heavy rain may even occur over Lesotho, which could rapidly raise the levels of the Gariep and Vanderkloof dams,” says Johan van den Berg, an independent agricultural meteorologist.
During this time, lighter rainfall is predicted over Gauteng, Limpopo and Mpumalanga, although rainfall of 20mm or more may occur in some areas. Very little rain is forecast over the summer rainfall region for the rest of April, says Van den Berg.
Winter rainfall region
Reasonably heavy rainfall may occur from Friday, especially on Sunday and Monday. This rainfall is expected over the Cape Winelands as well as further east. Heavy rainfall may occur in places like Paarl, Worcester, Caledon, Swellendam, and even George and Mossel Bay.
“Rain is also possible in the Klein Karoo in places like Oudtshoorn, Barrydale and Laingsburg, with rainfall of more than 20mm possible. There is a reasonably high risk of flooding in low-lying areas, especially along the south coast and adjacent inland areas,” says Van den Berg.
“Little rain is predicted over the Swartland, with more than 20mm expected over the Rûens and south coast.” The rainfall here may be sufficient to start preparing the first fields for planting. “The outlook for especially the Swartland looks less favourable for the second part of April and the first part of May.”
Cold and frost until mid-April
Frontal systems will move over South Africa in the next two weeks. The first system will move in on Friday and Saturday. Due to a high-pressure system typically moving behind a cold front, it will import cold polar air over the southern parts of the country. Temperatures may drop to near freezing, especially in the inland and northern parts of the Eastern Cape from Saturday until Tuesday. Another frontal system will also ensure that cold air moves over the country from 11 to 14 April.
“It is especially the second cold front that has the potential to bring colder air further north, possibly as far as the central and eastern parts of the Free State. It may also potentially cause frost.”
The drought conditions over large parts of the summer grain region have led to premature frost damage. However, there are still parts where late plantings of sunflowers and maize in the west may suffer frost damage.
“It does not seem like temperatures will drop sharply in the central to northern parts of North West in places like Lichtenburg. Places like Schweizer-Reneke and Bloemhof may experience frost in low-lying areas, with temperatures dropping to near 5°C or lower in lower-lying areas where frost pockets could occur with colder and heavier draining air,” says Van den Berg.
“After the temperature drops until about 10 April, it seems like the next real colder conditions may occur only in the second week of May.”
Risk for small livestock
The cold, wet conditions expected from Saturday until Wednesday 10 April could be accompanied by reasonably strong easterly winds, which could significantly lower the perceived temperature.
“With a wind speed of 15 km/h, a measured temperature can drop from, for example, 5°C to a perceived temperature as low as 2°C. A temperature of 0°C can then be experienced as a perceived temperature of -4°C,” says Van den Berg.
Sustained cloudy and rainy conditions with wind can create dangerous conditions for small livestock. These conditions are especially possible from Friday April 11 over central and northern parts of the Eastern Cape. “So, provide shelter, as well as high-quality feed for livestock to produce enough heat,” warns Van den Berg.
