15 Dec 2022 | 04:06 AM UTC
South Africa: Adverse weather forecast across most of the country through at least Dec. 18 /update 1
Severe weather forecast across most of South Africa through at least Dec. 18. Disruptions ongoing.
Event
Heavy rainfall and thunderstorms are forecast across most of South Africa through at least Dec. 18. Strong wind gusts and lightning could accompany thunderstorms. As of early Dec. 15, the South African Weather Service has issued the following weather warnings across the affected area:
Orange Level 6 (of 10) Severe Thunderstorm Warnings: most of Western Cape Province
Yellow Level 4 Severe Thunderstorm Warnings: southern and northeastern North Cape and the rest of Western Cape provinces
Rainfall is forecast across South Africa through at least Dec. 18. Officials could update and possibly extend the coverage of weather alerts over the coming days.
Heavy rainfall since Dec. 12 resulted in flooding in Western Cape Province; De Doorns, Worcester, Paarl, Ceres, and Gouda municipalities were the worst affected. At least 1,500 people in De Doorns Municipality have been affected and 50 informal structures were washed away. Several hundred other homes have been damaged. Authorities have confirmed one fatality in Soweto, Johannesburg City, Dec. 10 due to floodwaters. Thousands of people in Johannesburg City were without power; power has since been restored. Heavy rainfall Dec. 3 also resulted in flash flooding along the Jukskei River in the Alexandra area of Johannesburg City. Authorities confirmed at least 15 fatalities. Search and rescue operations are ongoing for the missing people. Further rainfall is likely to result in more flooding and hamper recovery and relief efforts.
Further sustained heavy rainfall could trigger additional flooding in low-lying communities near rivers, streams, and creeks. Urban flooding is also possible in developed areas with easily overwhelmed stormwater drainage systems. Sites located downstream from large reservoirs or rivers may be subject to flash flooding after relatively short periods of intense rainfall. Landslides are possible in hilly or mountainous areas, especially where heavy rain has saturated the soil.
Authorities could issue mandatory evacuation orders for flood-prone communities over the coming days. Disruptions to electricity and telecommunications services are possible where significant flooding or landslides impact utility networks.
Floodwaters and debris flows may render some bridges, rail networks, or roadways impassable, impacting overland travel in and around affected areas. Ponding on road surfaces could cause hazardous driving conditions on regional highways. Authorities could temporarily close some low-lying routes that become inundated by floodwaters.
Severe weather could also trigger flight delays and cancellations at airports across the affected region. Flooding could block regional rail lines; freight and passenger train delays and cancellations are likely in areas that see heavy rainfall and potential track inundation.
Localized business disruptions may occur in low-lying areas; some businesses might not operate at full capacity because of flood damage to facilities, possible evacuations, and some employees' inability to reach work sites.
Advice
Monitor local media for weather updates and related advisories. Confirm all transport reservations and business appointments before travel. Reconfirm the status of road routes before travel. Make allowances for localized travel delays and potential supply chain disruptions where flooding has been forecast. Do not drive on flooded roads. Charge battery-powered devices in the case of prolonged electricity outages.
