Snowfall blankets parts of Johannesburg as freezing winter weather continues to bite Gauteng
An advisory for icy conditions across Gauteng, where maximum temperatures are not expected to exceed 10C was issued by the South African Weather Service.
“We were just preparing to start our day, and then suddenly the weather changed – it was overcast and then the ice started falling,” said Jethro Moyo, a bricklayer in Johannesburg.
“We call it ice, we didn’t know it was snow, because when it falls down it melts!”
Like many people across Gauteng, Moyo was surprised to see snow falling on Monday morning, 10 July 2023.
The South African Weather Service (Saws) reported that this was due to an intense upper trough system and a cold front.
Wayne Venter, meteorologist and forecaster at Saws, explained to Daily Maverick that an intense upper trough system is basically an area of lower pressure in the atmosphere that meandered (hence the ‘trough;) due to strong winds (like the jet stream).
“What the snow needs to reach the surface is that the surface temperatures must be really low,” explained Francois Engelbrecht, professor of climatology and director of the Global Change Institute at Wits University.
Which is exactly what happened — Saws reported that a cold front caused a significant drop in temperatures over Gauteng on Monday, with maximum temperatures expected to reach 13°C in the northern areas of Gauteng and minimum temperatures recorded to have met criteria for snowy conditions.
As a result, snow was observed over areas in the south (such as Soweto, Alberton and Roodepoort) as well as the eastern areas of Gauteng, Heidelberg and parts of Vosloorus.
Engelbrecht said as it warmed up a bit below freezing in part of Johannesburg on Monday morning, it created perfect conditions for the snow, “because what happens is the ice crystals start to melt on the way from the cloud base to the surface, but not enough to completely melt away,” which is what Moyo saw.
“Then these melting ice crystals collide with each other, and then that way they form these larger snowflakes that are now right as I speak are still falling here on Wits campus,” said Engelbrecht.
The coldest day of the year
Venter reported that earlier this morning, minimum temperatures were the coldest so far this year, with Johannesburg dropping to -3C, OR Tambo to -4C, Irene to -1C, and Vereeniging to -5C.
“It was predicted to be the coldest day of the year so far in Gauteng,” said Venter, “the public should be advised that with the windy conditions today, temperatures may feel colder than the measured values due to the windchill factor.”
Venter explained that numerical model predictions indicated possible snowfall for parts of Gauteng for today (Monday) since last week and over the weekend, particularly for southern Gauteng, but models were struggling to predict moisture over Gauteng.
While many workers watched the snow falling behind their office windows or from home — excitedly taking to social media to share some snowy pictures — some had to be outside, braving the cold.
Tiney Chikanga, who sells his hand-crafted beaded sculptures on the intersection between Sandton Drive and William Nicole told Daily Maverick that they sat by the fire when it started snowing and that it was very, very cold. He has enough clothes, but is worried about others don’t.
Karabo Mahumane, a musician who plays near the same intersection said that while it was exciting to see the snow, it was very cold, and that this winter has been very bad.
Refuoe Mokuoane, a waste picker originally from Lesotho, told Daily Maverick that he was doing his collecting rounds (where he sifts through residents’ bins in the Northern Suburbs to find recyclable material that he can exchange for money) when it began to snow.
“I had to go and buy some tea because it was so cold today,” Mokuanae said laughing.
Like most waste pickers, Mokuoane sleeps at an informal sorting site and camp in Sandton during the week, before going back to his place on the weekend.
Waste pickers have to stay with their trolleys to look after the materials they collect throughout the week before a truck comes to pick up materials or before they drop off their collections at a recycling site or scrapyard on the weekend.
Mokuoane said this winter has been cold, and he uses a plastic sheet to keep him warm at night because he only has one blanket.
“I’m used to snow because in Lesotho every winter we saw the snow — it’s only that it was cold today,” said Mokuoane.
Moyo, the bricklayer, said when the snowfall got heavier they had to stop working and wait under the houses the construction team was working on.
“Ja it was annoying, but you know, to experience such a thing in our lifetime, it is something which is very exciting,” said Moyo, who said that he’s only seen snow in other provinces or on TV, but never in Joburg.
What causes it to snow?
“For snow to occur, several ingredients must be in place,” explained Venter. “First, there must be sufficient moisture in the atmosphere to produce precipitating clouds.
“Secondly, surface temperatures (usually at 1.5-2m) need to be 3 degrees Celsius and below. Lastly, the atmospheric freezing levels (which is the height above the surface where 0 degrees Celcius temperatures occur) should be low enough (over Gauteng freezing levels should be around or below 1,750m or 6,000 feet).”
“All three ingredients occurred this morning over southern and central Gauteng, causing snow and sleet to fall over parts of Johannesburg, in places over the West Rand, with noticeable snowfall occurring over the south-eastern parts of Gauteng such as Heidelberg and Alberton,” said Venter.
Liesl Dyson, meteorologist and associated professor at the University of Pretoria told Daily Maverick, “The process of making rain and snow is similar. Air cools down as it rises and then condensation takes place.
“When it rains this condensation process takes place higher and even if the drop freezes it melts as it falls and reaches the ground as rain. If it is very cold like today — the condensation and freezing of the droplets happens at much lower altitudes and they don’t melt before reaching the ground.”
Is it normal that it is snowing?
“This is normal, especially for winter. Most recorded snow events in the past over Gauteng occurred in winter — such as the snow events of July 1963, July 1964, July 1968, September 1981, August 2012 and today (10 July 2023),” said Venter.
Engelbrecht agreed that it’s not that exceptional that it’s snowing — nor is it due to climate change.
Light snow occurs in Gauteng roughly every five years, and this type of heavier snow occurs statiscally every 10 to 20 years, said Engelbrecht.
However, as per an article in the South African Journal of Science that Dyson mentioned, it’s valid to note that, “when snowfall does occur over highly populated areas, it causes widespread disruption to infrastructure and even loss of life.”
Weather for the rest of the day
“Looking at the forecast for today, cloud cover and light snow remain possible until this afternoon over south-eastern Gauteng, but it is expected to clear out this evening as the upper-air system will move further eastwards,” said Venter.
An advisory for very cold conditions (where maximum temperatures are not expected to exceed 10C over many parts of Gauteng) was issued for today by Saws.
What to expect from the weather in Gauteng for the rest of the week?
“The cold temperatures are here to stay for a few days,” said Venter. “A slight increase in maximum temperatures is expected from tomorrow but it will remain cold for the remainder of this week. Maximums will hover around 13C in the south to 16C over the northern parts of Gauteng from tomorrow (Tuesday).”
And the rest of the country?
Snow occurred over the mountains of the Western Cape, as well as the southern high ground of the Northern Cape (Sutherland) on Saturday into Sunday, which spread to parts of the Eastern Cape and KwaZulu-Natal on Sunday. Several warnings for disruptive snowfall are still in place for parts of the Eastern Cape high-lying areas, the south-western and western high ground of KwaZulu-Natal today and even the high ground of Mpumalanga. Snowfall and sleet are even possible in Mpumalanga, where maximum temperatures are expected to remain below 5C today.
The public and small stock farmers are advised that the very cold, wet and windy conditions may pose a risk to livestock, vulnerable crops and plants. The public is also warned to keep warm during these cold conditions and to regularly follow weather forecasts on television, radio as well as social media platforms. Updated information in this regard will regularly be available at www.weathersa.co.za, as well as via the SA Weather Service Twitter account @SAWeatherServic
It’s cold — how does global warming exist?
Willem Landman, a professor of meteorology at the University of Pretoria and a specialist in seasonal forecasts explained to Daily Maverick, “when it’s warming up, it doesn’t mean there is still inter-annual variability associated with that warming. So we are still getting cold winters and cool summers.”
To learn more about the difference between anthropogenic climate change (caused by humans) and climate variability (naturally occurring), read more in Daily Maverick: On the fence about climate change? We check the facts with three experts
“It’s just when it continues to warm as it is already warming up, we will see fewer events of extreme cold in the future, I think even in the near future. So it’s very likely that we will still get extreme cold snaps during winter for the foreseeable future,” said Landman.
Engelbrecht agreed, saying that, “I would say in a warmer climate, we can expect fewer of the snowfall events so far to the north,” explaining that a warmer world displaces cold fronts polewards, which will decrease South Africa’s chances of winter rainfall.
“That’s the most important impact for South Africa — but likely, our snow events over the Drakensberg and these exceptional ones further north, also will decrease statistically. But it doesn’t mean that they disappear completely. It just means that the seasons of good to winter rainfall. become less and less.”
When asked if he was happy that it stopped snowing, Moyo, the bricklayer in Joburg said, “We are happy [that it stopped snowing],” said Moyo, “but you — know nature has to play its part.” DM