4 July 2023
By: Alani Janeke
Frontal systems moving over the country from Friday may bring rain to the winter rainfall region over the weekend and in the first half of next week, as well as very cold conditions to the rest of South Africa.
The winter rainfall region can expect rain again from July 7 to 12. “The heaviest rainfall, exceeding 20 mm, is possible in the districts of Paarl, Stellenbosch, Somerset West and Grabouw. Rainfall of less than 20 mm is expected over the southern parts of the Swartland and the Overberg,” says Johan van den Berg, an independent agricultural meteorologist.
“Very little rain is expected over the more northern parts of the West Coast. Places like Nieuwoudtville and further north to Springbok, which have received a lot of rain in recent weeks, may receive less than 10 mm. Very little rain is expected in the Southern Cape and Garden Route.”
Van den Berg says minimal further rain is expected from July 13 to 23, though more may arrive in the last week of the month. “There is a lot of uncertainty for winter rain in August and September, which are important months for winter grain production, although the chances do not currently look unfavourable. An El Niño system is often favourable for late winter and spring rainfall.”
Chances of snow decrease
The chances of snow during the first two weeks of July have decreased. “Light snow may occur in the high-lying parts of the Eastern Cape, the Drakensberg, and surrounding areas,” says Van den Berg.
He says snow can still occur until September and the developing El Niño system increases the chances of snowfalls.
Cold, rain over summer rainfall region
Although heavy rain unexpectedly fell in parts of KwaZulu-Natal last week, no heavy rainfall is expected there in the coming weeks. Paddock, about 20 km inland from Port Shepstone, received approximately 320 mm on June 27 and 28, and Margate, along the coast, received about 160 mm.
Van den Berg says rain is possible along KwaZulu-Natal’s coast until mid-July, but heavy falls are not expected.
Minimal further rain is expected over the rest of the summer rainfall region for at least the next two weeks.
“Temperatures inland will not be as cold as predicted last week,” says Van den Berg. “With cold fronts affecting the country again from July 7 onwards, minimum temperatures can sharply drop from 8 July. Heavy frost is possible over the central to southern inland areas. Temperature drops can also occur further north. Frost can occur in places like Polokwane and Groblersdal, where temperatures can drop near freezing from July 8 to 13.”
Tornadoes, strong winds, and the El Niño system
Van den Berg says the strong winds or tornadoes reported in recent weeks, including in KwaZulu-Natal, are not unusual during the development of an El Niño system. In 1982, for example, when El Niño was also strengthening, there were several examples of very strong winds and tornadoes.
“On July 23 1982, a very severe storm hit Cape Town, causing significant damage. On September 1 1982, Bloemfontein was affected, and on October 10 a tornado hit Welkom. There were further examples of severe wind and storm activity in the 1982-83 summer season in places like the Swartberg, Creighton in KwaZulu-Natal, Pretoria, Bloemfontein, and Bloemhof.
“The risk is therefore very high for severe stormy weather conditions in the coming months.”
