The South African Weather Service (Saws) has issued a yellow level 2 warning for severe thunderstorms over most parts of Mpumalanga into the central and northern parts of Gauteng on Monday afternoon.
Isolated showers and thunderstorms are expected over the eastern provinces.
Saws forecast a 60% chance of showers and thunderstorms in the afternoon over Gauteng, Mpumalanga and the northern parts of KwaZulu-Natal.
Forecaster Lehlogonolo Thobela said there is a chance of minor impacts from heavy downpours, which could lead to localised flooding and possible damaging winds and hail in Gauteng and parts of Mpumalanga.
“Damaging winds are expected in the interior of KwaZulu-Natal, especially the southwestern parts, which may cause problems for high-sided vehicles. Along the south coast, we’re expecting damaging winds and waves that might result in navigation at sea being difficult and may disrupt some coastal activities,” he said.
For Tuesday, he said isolated showers and thunderstorms are expected mainly over the northeastern areas, covering Limpopo, Mpumalanga, parts of Gauteng and the northern parts of KwaZulu-Natal.
Tshwane emergency services said the weather system, caused by a cut-off low-pressure system, is expected to affect Tshwane from 2pm.
Its emergency services department spokesperson Nana Radebe-Kgiba said the department would continue to monitor weather conditions and remain on high alert to respond to any related emergencies.
Radebe-Kgiba said heavy downpours may cause localised flooding, particularly in low-lying areas, flat plains and vulnerable roads. Large amounts of small hail stones may fall in open areas, with damaging winds and lightning that could result in structural fires.
She said risks include traffic disruptions due to flooded roads and poor visibility, motor vehicle accidents on slippery surfaces, localised power outages, service disruptions and property damage, especially to roofs in formal and informal settlements.
Radebe-Kgiba advised residents to take safety precautions during severe thunderstorms.
These include staying indoors where possible and avoiding metal objects such as fences and power lines that can conduct electricity. She warned against outdoor activities such as fishing or playing golf as metal equipment can attract lightning. She urged people not to seek shelter under isolated trees or tall objects and to never attempt to cross flooded roads, bridges or swollen streams.
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