If you’ve been wondering why the summer was filled with wet and chilly days, you’re not alone. Usually, this time of the year we’d be scorching, but this time around a señorita called La Niña has the final say.
According to the South African Weather Service, the slightly cooler summer days are caused by a weather phenomenon called La Niña. This literally means “the girl” in Spanish.
Experts explain that La Niña comes around every two to seven years, resulting in the abnormal cooling of sea surface temperatures in the Pacific Ocean. It increases summer rains across the world, including in southern Africa.
While good rains are always appreciated in a water-scarce country such as Mzansi, it would appear that the rainy weather caused by La Niña is here to stay for the foreseeable future. And as farmers know very well, that comes with unintended consequences.
According to the agricultural meteorologist Johan van den Berg, La Niña has in the past been responsible for above-average rain in summer rainfall areas, often causing widespread flooding and diseases, as well as pests for the livestock industry.
However, the weather pattern also brings loads of good news, especially for those in the central to western parts of the country where drought is still a reality.
What to expect from La Niña
So, now that we’ve established why some South Africans have not ended their cuddling relationship with their favourite two-in-one winter blanket, let’s look at what La Niña has in store for the farming industry.
According to Van den Berg, the extent and amount of rainfall in December 2021 led to one of the wettest festive months ever recorded for considerable parts of the country, including winter rainfall areas.
Bothaville in the Free State received about 200mm in December, with parts of Wesselsbron and Bultfontein receiving between 200mm and 400mm. “The long-term average for December for these districts is in the order of 100mm.” Furthermore, close to the annual average has already been recorded since July, with another six months of the rainfall year still remaining.
In terms of what South Africans can expect this year, Van den Berg says the current forecast continues to favour substantial rainfall over the next two months. Strong rainfall is expected in the last few days of January, but especially in February.
“Expect substantial rains in the central-eastern parts, with showers progressively migrating westward until the end of February,” Van den Berg cautions.
He also flags an exceptionally high flood danger for the lower Vaal and Orange Rivers in the second to third weeks of January, and the first week of February.
The impact on farmers
Recent rains in parts of the Karoo and Kalahari are the best in years and will begin to assist in mitigating the impact of the droughts, believes Van den Berg. “Storage dams are virtually full, assuring water security for at least one summer season.”
More rain, however, is required to alleviate the drought, he believes. Ample rainfall is, however, good news for farmers as it signifies that grazing conditions for livestock will improve.
On the flip side, it can cause damage to maize crops in the Free State.
“In the north-western [part of the] Free State, large chunks of maize crops will not recover, and significant disease will arise.
“Large portions of maize fields in the north-western Free State will not recover, and animal disease will emerge as a result of the flooding, particularly where excess water pools into dams in lower-lying places,” Van den Berg predicts.
He also highlights that the rain is a stimulant for the hatching of brown locusts.
Don’t underestimate global warming
While the heavy rains are being blamed on La Niña, Van den Berg believes Mzansi is also seeing the consequences of climate change, which may have a significant impact on rain patterns.
“It is highly likely that 2022 to 2023 will see lighter rainfall conditions, with the next drought cycle expected to begin in 2025. Thus, this is part of the natural volatility of the climate with just a minor contribution from global warming,” he points out.
In order to adapt and survive these kinds of weather conditions, long-term planning is crucial.
“Right now, most of the damage is occurring in lower-lying places. Farmers must be aware of historical flood levels and choose fields that are less vulnerable to damage and usage.”
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