Emergency services in Tshwane and Johannesburg are on high alert following a yellow level 4 warning for severe thunderstorms issued by the South African Weather Service for Gauteng on Tuesday. The forecast predicts heavy rain, hail, and thunderstorms, potentially leading to flooding in susceptible low-lying areas, damage to infrastructure, and settlements due to strong, damaging winds. Several areas within Tshwane, including Centurion along the Hennops River, Pretoria North and West near the Apies River, Mamelodi and Nellmapius informal settlements, and Soshanguve and Mabopane, are identified as high-risk for flooding. Residents are urged to exercise caution, stay indoors, avoid contact with metal objects, refrain from sheltering under isolated trees, and not cross flooded roads or streams to mitigate risks such as localized flooding, structural damage from winds and lightning, traffic disruptions, vehicle accidents, and damage to homes.