By Alani Janeke
Residents of the winter rainfall region can expect stormy weather from Thursday onwards, with possible thunderstorms and even hail in some areas. A low-pressure system, set to bring significant rainfall to parts of Namibia on Wednesday, will extend southwards over the West Coast and western interior of South Africa by Thursday. As it merges with a cold front moving in from the southwest, it could lead to intense weather conditions, including thunderstorms and hail, in the winter rainfall region.
Namibians are thrilled about the recent good rains in places over the past few weeks. The low-pressure system is expected to bring substantial rainfall to large parts of the country, particularly from Wednesday onwards, before it extends southwards.
“The rainy conditions may spread across the rest of the winter rainfall region from the late afternoon of Thursday, 20 March,” says independent agricultural meteorologist Johan van den Berg. “It will begin to clear from the west the following afternoon as the system moves eastwards and northwards, extending into other parts of the country
Risk of hail
Van den Berg warns that the risk of hail poses a significant threat to the grape and fruit industry, which is still in the harvest season. Between 20 and 22 March, rainfall of more than 20 mm – and in some areas exceeding 30mm – is expected, particularly over the Cape Winelands and Cape Metropole. The Rûens and Southern Cape regions are likely to receive less than 20mm.
“Fairly heavy rainfall is also expected over the Eastern Cape, the south-eastern parts of the Northern Cape, the southern and eastern Free State, and adjacent areas of KwaZulu-Natal on 24 and 25 March.
He adds that localised heavy rainfall and flooding may occur, a pattern typical of this summer season.
Although the greater part of the summer rainfall region has received good rains, parts of the western and south-western Free State, along with adjacent areas of the Northern Cape, have experienced below-average rainfall so far this season.
Cold snap could further threaten summer grain crop
Van den Berg warns that the biggest threat to the summer grain crop – already impacted by drought in parts of the country – is a drop in temperatures and the potential for frost. Cooler conditions could prevent the grain from accumulating sufficient heat units, which are essential for achieving acceptable kernel weight and quality.
“Maximum temperatures of 20-25°C and minimums of 10-1°C provide only 5 to 10 heat units per day. This is far too low to complete the growing season if plantings were delayed,” he says.
