No specific weather pattern can be linked to what the upcoming winter might bring, considering the good rainfall that occurred in the first weekend and week of June across parts of the country.
Most of the rain fell in the Southern Cape, Klein Karoo, Garden Route and Eastern Cape. This was caused by the combined effect of a cut-off low-pressure system that brought warm, moist air from the northwest and cold air from the southwest, along with a cold front. Where these two air masses met, mixing occurred. The warm, moist air was cooled, leading to condensation and often heavy rain. The influence of topography, such as mountain ranges and wind directions, also played a significant role, leading to rapid weather changes.
The heavy rains caused significant damage in some areas. However, the good rainfall of up to 50 mm or more, with relatively heavy snowfall in southern parts of the Free State, southeastern parts of the Northern Cape, almost the entire Eastern Cape, and the Klein Karoo and Groot Karoo in the Western Cape, also had a positive effect on soil moisture, particularly for green fodder.
“This will also cause relatively rapid regrowth of pasture after winter, making grazing conditions very favourable in the early part of summer,” says Johan van den Berg, an independent agricultural meteorologist.
What could happen in the coming months?
Van den Berg says that looking at similar years in the past, when the El Niño system was transitioning to a La Niña, no similar rainfall conditions to last week’s floods could be found.
“The recent floods in the Garden Route, Klein Karoo and the Eastern Cape can be attributed more to local factors such as warmer conditions over the western Atlantic Ocean off the West Coast, as well as what is happening in the Indian Ocean. Here, climate change could play a significant role.
“In recent months, the surface of both the Atlantic and Indian oceans has been warmer than normal. However, since March 2024, cooling has occurred in a narrow strip along the west coast of Africa and in a larger area in the adjacent Indian Ocean (south of Madagascar).
“There were thus very large temperature gradients that could have a significant impact on weather systems. During April, there were still relatively strong tropical storms north of Madagascar due to warmer than normal sea surfaces in the Mozambique Channel and further north, with cooler water to the south.”
Currently, there are no strong trends on which predictions can be made with certainty, says Van den Berg. “With relatively few frontal systems having moved over the country so far, the chances are good that there will still be quite a bit of cold front activity from the last week of June, but especially in July and August.
“There are thus indications that average to slightly above-average rainfall will occur in July and August over the winter rainfall area. There is also still a chance that similar systems to those that occurred from the beginning of June can occur over the Southern Cape and the adjacent interior as well as in the Eastern Cape and even KwaZulu-Natal’s coastal areas.
“Weak low-pressure systems remain present over the western Atlantic Ocean, the western and northwestern interior, and the adjacent parts of Namibia, which can quickly strengthen as frontal systems move in.”
Rain and snow
Light rainfall due to cold fronts is possible around 12 and 20 June over the Swartland of the winter rainfall area, with heavier rainfall possible in the last few days of June and the first two weeks of July. Over the next few weeks, lighter rain is expected over the Winelands, the Ruens and the Southern Cape, with a chance of light rain about once a week.
Over most of the summer rainfall area, very little or no rain is expected for the next few weeks. “Around 20 June, but especially on 29 June, there is a chance of rain and snow over the northern parts of the Eastern Cape and the adjacent parts of the Free State and KwaZulu-Natal.”
July, August the coldest
Van den Berg says low minimum temperatures will continue over southern parts of the country in the coming weeks, while daytime temperatures are starting to recover. “A place like Barkly East in the Eastern Cape can experience minimum temperatures of between -1°C and -5°C or lower for at least the next month to six weeks continuously.
“Low temperatures and frost can occur until September, and even early October, over the Free State, Northern Cape, Eastern Cape, and the interior of the Western Cape. Low temperatures with a possibility of frost can also occur until the end of July or early August over the warmer northern areas, particularly Limpopo. The coldest part of winter is expected to be in July and August.”
With the extremely cold conditions and snow that have occurred recently, farmers are on alert regarding shearing times.
Van den Berg says conditions look reasonably favourable for the next few weeks, although very cold conditions and low minimum temperatures will still occur.
“It is when rain and strong winds occur together with the cold that conditions can become very dangerous.”
For the Eastern Cape and southern Free State, there is a chance of light rain around 10 and 19 June, with more rain possible around the end of June and in the first week of July.
“The major danger is when cut-off low-pressure systems – like in the past week or two – develop. These develop very quickly while the area they can impact, as well as the duration, are very unpredictable. It is therefore of utmost importance to take the necessary precautions to be able to act quickly when there are indications that more rain can occur,” says Van den Berg.
