20 May 2022 | 11:58 AM UTC
South Africa, Lesotho: Adverse weather forecast across central, southern, and southeastern regions of South Africa and Lesotho through at least May 22 /update 1
Severe weather forecast across parts of South Africa and Lesotho through at least May 22. Flooding and associated disruptions possible.
Event
An active weather system is expected to bring heavy rainfall, thunderstorms, and snowfall over higher aground across central, southern, and southeastern regions of South Africa and across Lesotho through at least May 22. Heavy rainfall is expected across parts of Eastern Cape Province May 20, spreading inland to parts of eastern Northern Cape, western Free State, and southern North West provinces. Thunderstorms are possible over much of Free State and North West provinces May 20-21 and heavy rainfall will move into KwaZulu-Natal Province May 21, with the heaviest downpours expected over coastal areas. Light snowfall is possible over elevated areas of Western and Eastern Cape provinces May 20, spreading into the Lesotho Drakensberg mountains May 21-22. The passing of the cold front will also see a drop in temperatures across the affected area.
As of May 20, the South African Weather Service (SAWS) has issued the following weather warnings:
Orange level 5 of 10 disruptive rain warnings: West-central parts of Eastern Cape Province and southern and central coastal regions of KwaZulu-Natal Province.
Yellow level 4 of 10 disruptive snow warnings: Parts of northeastern Eastern Cape.
Yellow level 2 of 10 disruptive rain and thunderstorm warnings: Parts of central and western Eastern Cape, eastern Northern Cape, Free State, southern, central, and eastern North West, and much of KwaZulu-Natal provinces.
The Lesotho Meteorological Services has issued a press release warning of moderate to heavy snowfall and widespread rainfall across the country May 20-22.
Officials will likely issue new alerts or update/rescind existing advisories as weather conditions change.
The orange disruptive rainfall warnings cover areas of KwaZulu-Natal Province which are still recovering from major flooding following heavy rainfall April 11-13. The severe flooding caused at least 443 fatalities and over 40,000 people were displaced, mostly in Durban and surrounding areas. Nearly 4,000 homes were destroyed and over 8,000 others damaged by flooding and landslides. Further rainfall in the region could trigger additional flooding due to high groundwater saturation levels and may hamper ongoing recovery efforts.
Hazardous Conditions
Sustained heavy rainfall could trigger 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 areas, especially where the soil has become saturated by heavy rainfall.
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.
Precipitation could fall as snow in the higher elevations over the coming days. Wind gusts could cause blowing and drifting snow; decreased visibility is likely in mountainous areas.
Transport
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.
Heavy snowfall will likely make driving hazardous in some areas; authorities could implement temporary road closures or detours in such locations. Mountain passes and tunnels could be closed as a precautionary measure during periods of intense snowfall.
Severe weather could also trigger flight delays and cancellations at airports across the affected area. 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. 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.
