South Africans can expect a cold snap to affect most parts of the country from Tuesday until Thursday.
The South African Weather Service said in a statement that a steep upper-air trough, having the potential to cut off and further intensify, would result in significantly cooler weather over most parts of the country this week, with the expectation of snowfalls on some southern mountains.
“Maximum temperatures of the order of 16 to 19 °C will affect the southern parts of the Western Cape from Tuesday (November 14, 2017), with cold weather spreading further eastwards and northwards on Wednesday and Thursday.”
Cold weather, they said, would invade the Eastern Cape, southern KwaZulu-Natal, southern Free State and the Northern Cape on Wednesday, spreading to reach the remainder of KwaZulu-Natal, the Free State, Gauteng and Mpumalanga on Thursday, accompanied by maximum temperatures in the mid-teens.
“However, very cold weather, characterised by single digit maximum temperatures (9 °C or less), will dominate high-lying areas of the Eastern Cape and south-western KwaZulu-Natal on Thursday.”
They said “significantly cooler weather” in the upper-air would result in light snowfall over the high ground of the Western Cape as well as the western high ground of the Eastern Cape from Wednesday morning (November 15, 2017) onwards.
“Snow is expected to subsequently spread eastwards to include the eastern parts of the Eastern Cape by Wednesday afternoon, where it will become heavy and disruptive (with respect to traffic and infrastructure) over the north-eastern mountains of the Eastern Cape (Rhodes, Barkly East) and Lesotho.”
Snowfalls of this nature, they said, typically led to the closing of mountain passes, resulting in associated disruption to traffic flow.
“Further snowfalls, of a light to moderate nature, are expected to spread to the south-western and western high ground of KwaZulu-Natal as well as the south-eastern and eastern extremities of the Free State on Thursday.
Heavy rainfall (in excess of 50 mm in places in the Eden Districts) will also spread eastwards to parts of the Eastern Cape, KwaZulu-Natal and eastern parts of Mpumalanga on Wednesday.
“Although rainfall is expected across most parts of the country on Wednesday, the heaviest rainfall is likely to be restricted to the aforementioned provinces. Instances of flooding can also be expected during this period.”
They said the intensity of rainfall was expected to ease off from the west on Thursday, but it will persist over parts of Mpumalanga, KwaZulu-Natal, the eastern parts of the Free State and in the Eastern Cape.