The South African Weather Service (SAWS) has issued a yellow level 2 warning for severe thunderstorms in Gauteng, and the western and southern parts of Mpumalanga on Thursday.
"Thunderstorms are expected to develop from the late afternoon over southern Gauteng and southern Mpumalanga, and will move northwards to the rest of Gauteng and the western parts of Mpumalanga in the evening," the weather service said.
Scattered rainfall of 15mm to 25mm can be expected, with heavy downpours of 30mm to 40mm possible in some areas. This may lead to localised flooding in susceptible areas, which may result in localised flooding of susceptible roads and low-lying areas due to heavy downpours, as well as localised flooding of informal settlements.