The South African Weather Service (SAWS) has warned residents in the eastern part of the country to brace themselves for a stormy weekend.
According to the weather service, affected provinces include Gauteng, Mpumalanga, Limpopo, the north-eastern Free State and western KwaZulu-Natal.
"Storms in some of these areas may become severe, producing one or a combination of the following; large hail, abundance of small hail and heavy downpours which could lead to localised flooding and strong damaging winds," it warned in a statement on Thursday.
SAWS said the extreme conditions were the result of the presence of an upper air trough over central parts of the country.
'Stay indoors if possible'
It warned that roads may be flooded which could disrupt travelling and also possibly damage infrastructure.
Members of the public have been advised to stay indoors and keep off the roads if possible. They have also been urged to avoid crossing rivers and swollen streams where water is above the ankle.
The weather services also advised those in the affected areas to move their valuables to places that are safe from flooding and to also relocate livestock to higher ground.
"The South African Weather Service will continue to monitor any further developments relating to this weather system and will issue subsequent updates as required," SAWS added.
The eastern half of the Eastern Cape, KwaZulu-Natal and the Highveld of Mpumalanga will be cooler on Saturday with cooler air expected to spread through to Gauteng and Limpopo on Sunday, SAWS said.