The South African Weather Service says a strong cold front, with an associated steep upper trough, is expected over the Western Cape and Namakwa District of the Northern Cape.
Spokesperson Hannelee Doubell said gale-force, north-westerly winds of 65-70km/h are expected between Cape Columbine and Cape Agulhas tomorrow, moderating overnight.
Strong to gale force, gusty north-westerly winds (50-70km/*) are expected over the Western Cape and Namakwa District interior Thursday into Friday.
“Significant rainfall amounts can be expected from tomorrow morning, where spells of heavy downpours are likely, from late morning into the afternoon. Accumulated rainfall amounts of 10-25mm can be expected, with 30-50mm over the mountains,” Doubell said.
Intermittent rain and showers are expected to continue over the western half of the Western and Northern Cape on Friday, with a further 10-20mm likely over the western mountains.
“Large accumulations of water will result in flooding of roads, as well as formal and informal settlements. This may result in damage to property and lead to a disruption in services to communities. Due to the vastness of the areas and District Municipalities covered, this may put short-term strain on emergency personnel.
"Heavy downpours tomorrow could result in flash flooding, possibly affecting transport routes and low-lying infrastructure,” she said.
Mudslides and rockfalls are also possible.
“As it is exam time, students in rural communities should be advised when making their way to and from school.
“Strong to gale force and gusty crosswinds along the (Western Cape) N1 highway may result in this major route as well as corresponding rail transport being adversely affected. Hazardous driving conditions may result in road accidents along this route. Moreover, high-sided vehicles are at risk of being toppled by intense wind gusts along the route.
Gale force, gusty winds may result in localised damage to informal as well as formal structures and infrastructure. Travel routes may also be affected,” Doubell said.
The weather service has warned that coastal damage may occur along the south-west coastal regions and small vessels should ideally remain in port during this period.
“Farmers are advised that the combination of cold, wet and windy weather may prove fatal to stock, unless animals are taken to shelter ahead of the onset of the extreme winter weather,” Doubell said.
Updated information can be found at www.weathersa.co.za