The sattelite image shows the double front moving across the country. The SA weather service says it's not unusual, but a fairly typical winter system.
  • Two cold fronts are hitting South Africa this weekend.
  • Temperatures will drop sharply and suddenly across the country.
  • Joburg and Pretoria will be in the single digits on Saturday.
  • Watch out for flooding, wind, and veld fires.
  • For more articles, go to www.BusinessInsider.co.za.

The series of cold fronts hitting South Africa this weekend will be felt in Johannesburg and Pretoria too. 

And you should get ready – the fronts will continue battering the country all the way into September.

The South African Weather Service says a double cold front is approaching the west coast of South Africa. It’s already started to land, bringing strong winds across the south.

Here's what it looked like in the early hours of 10 July, according to a satellite image released by the SA weather service:

The cold front blanketing the Cape in the early hours of 10 July

But it’s not just the Western Cape that will feel it. According to Kevin Rae, chief forecaster at the South African Weather Service, it’s going to get very chilly this weekend across most of the country.

By Saturday, as the front moves over the interior of the country, most major cities, including Johannesburg, Bloemfontein and Pretoria will be experiencing temperatures in the single digits.

Light snow is expected in the mountains of the Western and Eastern Cape and Lesotho, with the weather service predicting snow might fall as far north as Namibia.

But it’s the Western Cape that’s going to bear the brunt of the double front, with the weather service warning of flooding and gale force winds. If you’re thinking of driving near Cape Town this weekend, perhaps change your plans.

Here are the big dangers to watch out for:

Gale winds

According to the weather service, the fronts are bringing gale force winds of between 60km/h and 75km/h. That’s enough to dislodge old trees, and cause damage to homes, especially in informal settlements. The gales will be felt over much of the interior, and it’s particularly road users who should be worried, as trucks are in danger of being knocked over by strong crosswinds. The weather service singled out the area around the Huguenot tunnel outside Paarl but cautions against travelling on the N1, N2, N7 and R60 in the Western Cape.

The fronts will also cause very high waves of between 6m and 8m, particularly in the area between Cape Columbine and Cape Agulhas, which means all along the South West coast, with Cape Town smack in the middle. The waves will be biggest tonight and tomorrow night, says the weather service. They suggest staying away from beaches and boats for the next few days.

Flooding

Heavy rain is expected in Cape Town, and that’s likely to cause flooding. The weather service says roads and low-lying settlements are likely to be impacted. It will put big pressure on essential services as well.

A danger to animals

It’s going to get cold really quickly. “The drop in temperature will be quite dramatic,” says Rae. He says small stock farmers, particularly in the Eastern Cape, should be prepared to cover their animals or bring them inside in the evenings.

Fires

One of the big dangers of a cold front during late winter is veld fires caused by bergwinds. The cause is pretty simple – the front is approaching from the west, and pushes air before it, like compressing air in a bicycle pump. As the front moves closer to the interior of the country, air is pushed down from the escarpment, and to the south coast. When air is forced lower, it quickly warms up, and blows as a hot, dry wind. In winter, when grass is dry, a spark can quickly turn to a fire. And bergwinds can quickly take that small fire and turn it into a major, widespread disaster.

It’ll soon be over – but not for long

The good news is that the double front will pass by fairly rapidly, says Rae, with warmer temperatures returning early next week. But fresh systems are already developing, he says.

“We’re by no means out of winter yet. These types of systems occur every seven to ten days, and can be felt right up to much of September.”

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