Winds of Change – It’s a Sign!

Did you ever notice how the increased winds in August in South Africa’s interior are closely linked to the seasonal transition from winter to spring?

Vox Weather Meteorologist Michelle du Plessis tells us more.

During winter, much of South Africa is dominated by a stable high-pressure system over the interior. By late winter, this high-pressure system begins shifting as the Intertropical Convergence Zone (ITCZ) also moves further south, while cold fronts from the southwest continue to pass across the country.

The interaction between these different air masses, namely colder, denser air from the west and warmer, lighter air building over the interior, creates a tighter pressure gradient. A tighter pressure gradient causes air to move faster, which is experienced as stronger winds. 

At this time of year, vegetation and soils are generally at their driest after months of limited rainfall. This allows dust and sand to be lifted more easily by the wind, and also creates ideal fuel for fires. The combination of dry vegetation, low humidity and strong winds makes it far easier for flames to spread rapidly and become uncontrollable. 

These conditions are a key reason why August is one of the worst times for any open burning, as even a small spark can quickly escalate into a runaway wildfire.

When Will the Rains Come?

The ‘August winds’ is generally a late‑winter feature that usually builds from late July, peaks through August, and fades during early to mid‑September. Mechanistically, the windiness is driven because of strengthening pressure gradients between lingering cold fronts to the southwest and a warming interior.

In most years, the interior’s first spring showers arrive mid to late September, but they’re usually light and isolated. The true start of the rainy season, with consistent, useful rainfall, tends to occur from October into early November.

Recent research confirms a shift toward a later onset of rain, especially in Gauteng and surrounding areas. What was once expected in September now often only establishes in October or even November.

This trend is linked to climate change and ENSO cycles, with El Niño years delaying rain and La Niña favouring earlier onset.

The bottom line is that the spring rains are coming, but they’re running later than they used to.

As the frontal influence relax and low‑level moisture flux from the northeast strengthens, winds generally ease from their late‑winter peaks and thunderstorm days begin to appear.

A practical rule of thumb is a one to four week overlap or transition: the gusty late‑winter pattern tapers off in early to mid-September; the first weak convective events pop up mid‑ to late September; and finally more reliable rainfall usually arrives in October.

Are We Seeing a Change in the Beginning of the Seasonal Spring Rains?

The short answer – in Michelle’s opinion – is yes.

She believes that there has been a change in the beginning of the seasonal spring rains in South Africa in recent times.

It matters because:

  • Rainy seasons are arriving later, shortening the wet window: A study across southern Africa confirms that the wet season is starting later, which also means shorter rainy periods and lower overall rainfall in many regions.
  • Climate change is a major culprit: Longer-term climate projections, especially under high emissions scenarios, suggest that shifts in global rainfall timing are already underway. In southern Africa, these shifts are tied to delayed wet-season starts, likely influenced by warming trends and changes in atmospheric circulation.

The Role and Effects of Fire

In the Western Cape, fire is essential for fynbos regeneration. In the interior grasslands and savannas, fire also plays an important ecological role, but timing and intensity matter.

Well-timed, cooler burns (usually done controlled, under calm, moist conditions) help remove old grass, stimulate new growth, and control bush encroachment.

However, August fires driven by strong winds are often too hot and fast, making them more destructive than beneficial. These fires can damage soil, kill recovering vegetation, and destroy grazing land.

So while fire is natural and even necessary in some ecosystems, the August fire season in the interior is more risky than helpful, especially when fires are uncontrolled and fuelled by dry, windy weather.

What Does This Mean on the Ground?

Farmers, planners and residents relying on spring rains can no longer count on September showery starts. In practice, October is fast becoming the more dependable month for meaningful rainfall, especially across Gauteng and the interior.

The bottom line?

Yes, spring rains are shifting later in South Africa. Research confirms that it’s happening, and that climate changes are steering the trend.

  • Recent studies show that the later start to the rainy season is linked to a combination of climate change and natural climate patterns.
  • Climate change is shifting weather patterns globally, including when and how rain falls in South Africa. Warmer temperatures affect how long dry seasons last and delay the arrival of reliable rain.

El Niño and La Niña also play a role. El Niño years tend to bring later and weaker rains, while La Niña often brings earlier and wetter conditions. We are expecting a weak La Niña to develop by summer, which may result in above-normal rain in the summer over the summer rainfall regions.

Extra! Extra! Read All About It! Total Lunar Eclipse 7 September 2025

This is a celestial event you won’t want to miss — and one of the best lunar eclipses visible from South Africa in years.

Stargazers around the country have been waiting impatiently for a stunning astronomical spectacle that’s taking place on the night of Sunday the 7th of September 2025, when a rare total lunar eclipse, commonly called a Blood Moon, will be visible across the country. Grab your warm jackets (it can still be cold during September evenings) and get comfortable as the sky puts on an amazing show!

Vox Weather Meteorologist Michelle du Plessis tells us more about how lunar eclipses are formed, and the weather we can hope for on Sunday night.

What is a Lunar Eclipse?

A lunar eclipse happens when the Earth passes directly between the Sun and the Moon, casting its shadow onto the Moon. This only occurs during a full moon.

There are three types of lunar eclipses:

  1. Penumbral Lunar Eclipse – the Moon passes through Earth’s faint outer shadow (the penumbra), causing only a slight dimming.
  2. Partial Lunar Eclipse – part of the Moon passes through Earth’s dark central shadow (the umbra), and a section appears darkened.
  3. Total Lunar Eclipse – the entire Moon moves into Earth’s umbra, turning a reddish colour — often called a ‘Blood Moon’.

 

During a total lunar eclipse, the Earth blocks direct sunlight from reaching the Moon. However, sunlight still filters through Earth’s atmosphere and bends (or refracts) around the planet.

Shorter blue wavelengths are scattered, and the longer red and orange wavelengths reach the Moon — causing it to glow red or copper.

It’s the same effect that gives us red sunrises and sunsets — except this time, you’re seeing it reflected back from the Moon!

This TikTok video from Michelle shows us more on how lunar eclipses take place – together with a quick weather overview for the country’s stargazing.

The 7 September 2025 eclipse is special because:

  • It will be a total lunar eclipse, with the entire Moon turning red.
  • It will last 82 minutes, making it one of the longest lunar eclipses of the decade.
  • It will be visible across South Africa.
  • No telescope is needed — you can see it with the naked eye if skies are clear.

South Africa Viewing Details and Weather Conditions

The table shows the key moments to look out for. The best time to watch is between 7:30 PM and 8:52 PM, when the Moon will be completely within Earth’s shadow and glowing red.

The weather conditions for 7 September across the country will be mostly favourable for viewing the total lunar eclipse on Sunday evening.

  • However, around the Southern Cape, including parts of the Garden Route and Overberg, we are expecting widespread cloud cover, which will most likely obscure the view of the eclipse.
  • In contrast, much of the interior, including the Free State, North West, Limpopo, and Gauteng, will experience partly cloudy skies with high to mid-level cloud, allowing for intermittent but generally good visibility of the eclipse.
  • Cape Town is also expected to have clear enough skies, especially earlier in the evening, making for a great viewing opportunity.
  • Coastal areas in KwaZulu-Natal and parts of the Eastern Cape may see some coastal cloud or mist, especially early evening, but breaks in the cloud are possible later on.

For the best view, try to find an open area away from city lights — ideally elevated, with an unobstructed view of the eastern horizon where the Moon will rise.

Tips for Watching and Photographing

  • Dress warmly — it’s still chilly at night in September.
  • Use a camera with manual exposure settings if possible.
  • For smartphone users: Tap to focus on the Moon and reduce brightness for better contrast.

 

Fun Facts

  • A lunar eclipse can only occur during a full moon.
  • Unlike a solar eclipse, lunar eclipses are safe to view with the naked eye.
  • The Moon doesn’t completely disappear — it turns red due to Rayleigh scattering in Earth’s atmosphere.

Why Is It Called a “Blood Moon”?

The term ‘Blood Moon’ comes from the deep red colour the Moon takes on during totality. Ancient cultures often saw it as an omen, but today we know it’s simply the effect of Earth’s atmosphere bending sunlight.

Mark your calendars and if skies are clear, look up and enjoy the show!

How SA’s winter weather patterns compare to our neighbours

South Africa is one of the few countries in southern Africa that regularly has snow  – in places – in winter.

Vox Weather Meteorologist Michelle du Plessis tells us more.

South Africa’s climatic diversity is largely due to its geographic position at the southernmost tip of Africa, where it’s influenced by both the warm Agulhas Current on the east coast and the cold Benguela Current on the west coast. Its varied topography – ranging from high plateaus to mountain ranges like the Drakensberg – creates conditions cold enough for snowfall in winter. Being the furthest south on the continent, South Africa is also directly affected by mid-latitude cyclones and cut-off low-pressure systems. When looking at our neighbouring countries, clear contrasts emerge in winter weather patterns.

(Image left courtesy Mantle Plumes; Image right courtesy Vox Weather)

Lesotho, though an independent country, is entirely landlocked within South Africa.

Its high elevation – most of the country lies above 1,800 metres – means it experiences regular snowfall in winter, particularly over the Maloti Mountains, much like surrounding high-lying areas of South Africa.

(Photo courtesy Snow Report SA / Marietjie Hayward)

Namibia and Botswana experience dry, sunny winters with cool nights and warm days, but their generally low elevation and arid conditions make snowfall virtually impossible.

In Namibia, bergwinds or “oosweer” often bring warm, dry weather and occasional sandstorms as strong north-easterly winds prevail after the passage of cold fronts. Although rare, light snowfall can occur in the far south of Namibia when a particularly strong cold front moves unusually far north.

Zimbabwe and Mozambique have subtropical to tropical climates. Their winters are dry and mild, with average temperatures rarely dropping low enough to produce frost, let alone snow.

Eswatini experiences slightly cooler conditions in winter, especially in its highland areas, but snowfall is extremely rare due to its lower elevation and more humid climate.

(Map image courtesy of BBC News)

These regional differences highlight how South Africa’s southern location, combined with its topographical range and oceanic influences, makes it uniquely positioned to experience a wide variety of winter weather, including rain and snow – conditions seldom seen in its neighbouring countries.

(Click here to find out how snow weather occurs.)

Snow possible in central SA and Gauteng this week

Forecaster warned that snow is possible in central SA and Gauteng this week. Here is the latest weather update.

Snow in Gauteng? Weather models are pointing to a rare wintry mix for the province this Thursday as a powerful cut-off low sweeps across South Africa, bringing freezing temperatures and the potential for snow, hail, or graupel.

While actual snow settling in Gauteng remains unlikely due to higher ground temperatures, forecasters warn that conditions may be cold and unstable enough to produce soft hail or snow-like precipitation.

Full article

The Effect of Climate Change on South Africa’s Winter Weather Patterns

What is happening to SA’s winters and is climate change playing a significant role? Vox Meteorologist Michelle du Plessis tells us more.

Data shows that winter temperatures across southern Africa have been steadily rising since the 1960s, with fewer days of frost and freezing conditions.

According to the NOAA, extreme cold events are now far less common – and when they do happen, they’re generally milder than in the past.

In the Western Cape, where winter rainfall is vital, climate models show that the rainy season is becoming shorter and more variable.

While some winters still bring strong cold fronts and good rainfall, others are marked by long dry spells.

The WMO warns that drought risks are increasing, especially in Mediterranean-type climates like the south-western Cape.

Interestingly, while total rainfall may decrease, when storms do occur, they may be more intense – bringing short bursts of heavy rain rather than steady soaking periods. This is because warmer air holds more moisture, which can lead to more powerful frontal systems when they develop.

Recent studies suggest that mid-latitude frontal systems – the cold fronts that bring winter rain – may grow stronger under climate change. However, this doesn’t mean we’ll get more of them. Instead, we may see fewer, but more intense, winter storms, followed by longer dry periods in between.

What this means for South Africa

In short, South African winters are becoming:

  • Warmer, with fewer frost days;
  • More variable, with rain falling in short, intense bursts; and
  • Less predictable, meaning long-range planning is harder.

A Note on Snow Forecasting at Vox Weather

Some early snow forecasts recently circulated on social media suggested possible snowfall over parts of Gauteng, North West, the Highveld, and other areas that rarely experience snow during late July. At Vox Weather, we chose not to post about these projections – and here’s why.

Advanced snow forecasts, particularly more than five days ahead, are often subject to significant change. In fact, updated model guidance today NO LONGER indicates snowfall over these north-eastern regions at all.

Our approach as meteorologists to snow forecasting involves more than just looking at model snowfall outputs.

We analyse:

  • The SYNOPTIC SYSTEM expected (e.g. a cold front or cut-off low);
  • The availability and timing of PRECIPITATION; and
  • The FREEZING LEVELS (the altitude at which temperatures are cold enough for snow to form and reach the ground).

These factors must all align for snowfall to be possible. A shift in any of them can lead to significant changes in where snow may fall – or if it occurs at all.

As of the latest forecast, we see:

  • A cold front expected to move in on Friday 25 July.
  • A strong ridging high-pressure system to follow, introducing colder air over southern South Africa during the weekend of 26 and 27 July.
  • Forecast snowfall now largely restricted to the Eastern Cape, Lesotho, the southern Free State, and adjacent high-lying areas.

At Vox Weather, we prefer to wait until we see consistency in multiple forecast runs – usually within a five-day window – before communicating potential snowfall.

 

This ensures that our updates are as accurate and reliable as possible.

Snow Patrol!

The arrival of snow isn’t an everyday occurrence for most of South Africa.

As we find ourselves back in snow season, we sat down with Vox Meteorologist Michelle du Plessis to give us the lowdown on how snow is formed.

And it turns out that, for snow to fall and reach the ground, three main weather conditions must come together.

Cold air from top to bottom: The air must be below freezing (0 °C) all the way from the clouds to the ground. If there’s a warmer layer in between, the snow will melt and fall as rain or sleet. Ideal snow forms in clouds where temperatures are between -10 °C and -20 °C.

Enough moisture in the air: Cold air alone isn’t enough – you also need moisture so that water vapour can form ice crystals. Dry air, even if freezing, won’t produce snow.

Something to lift the air: Snow usually forms when air is forced to rise, cool, and condense. This can happen with cold fronts, low-pressure systems like cut-off lows, or when air is pushed up over mountains.

Gauteng’s last snowfall: July 2023…

In July 2023, Gauteng experienced rare snowfall – something locals hadn’t seen in over a decade (before 2023 it snowed in 2012 and 1996). While light snow sometimes falls in the province, heavier events like this happen only once every 10 to 20 years. So yes, it was unusual, but not unheard of.

The July 2023 cold snap wasn’t driven by climate change – instead, it was the result of a powerful cold front that swept across the entire country and extended into our neighbouring countries – supported by a steep upper-air trough, pushing icy air far north.

Looking ahead to winter 2025…

We find that the odds of another snowfall in Gauteng remain low. Climate trends suggest snow in the region will become even rarer in future. That said, nature still has surprises.

If the right weather patterns align—such as a strong cold front or cut-off low pressure system – we could see isolated snow again. But it would remain the exception, not the rule.

Half a Million Followers and Climbing!

As Winter 2025 tightens its grip, more and more viewers are tuning in every day to the skilled presentation and deep expertise of Vox Weather’s popular Meteorologists, Annette Botha and Michelle du Plessis.

Vox Weather, which was launched and managed by telecommunications and IT services provider Vox, is now proudly on the peak of reaching 500,000 followers as South Africans across the country rediscover the joys of a daily weather update that’s presented with flair and style.

So it’s “Goodbye app…” and hello to “No matter the weather, we’re in this together!” as we tune into the daily weather news.

The first significant milestone was reached when Vox Weather grew to 50,000 followers within the first six months of launching in late 2021. After this, the platform took just another year to double up to 100,000 dedicated followers, and a reach of close to two million people per month, on average, in its first 18 months. Now, in mid-2025, Vox Weather is on the bridge of crossing the half a million mark – groundbreaking and impressive indeed.

But what is making the Vox Weather channel so successful? There are probably multiple reasons for this, but Vox Social Media Specialist Lynelle Davids, who tracks the Vox Weather statistics regularly, has some ideas. 

“For starters,” she says, “it helps that the weather is presented by two living, breathing rays of sunshine… but seriously, there are indeed multiple reasons for the growth. Besides the interesting content – the weather is important to everyone! – the animated graphics are modern and eye catching, but also easy to understand. There is, of course, serious technology behind each graphic that they share.

“Annette and Michelle are both highly qualified scientists, bringing credibility to their weather presentations – they really understand what they are telling the viewers; in fact, they prepare the visuals themselves from the raw data.

And Vox Weather makes excellent use of available social media platforms to actively market its content. This includes sharing different types of information across the channel’s home web page as well as Facebook, YouTube, X, Instagram, WhatsApp  and LinkedIn.”

Annette says: “We are so humbled to have achieved this important milestone of 500,000 followers, and appreciate the time and trust our audience has placed in us by regularly tuning in across the various platforms for the latest updates. As we like to say: it’s all about putting the ‘WE’ back into weather!”

Michelle adds: “It’s a joy and an honour to deliver a presenter-led weather report, together with animated graphics. It’s our belief that this truly helps to bring the weather to life with a real personal touch.”

 

 

According to Lynelle, there have been some interesting additional milestones achieved lately for Vox Weather’s social media numbers.

“We recently saw an incredible spike in followers on Facebook,” she clarifies, “when Annette and Michelle gained 5,300 new followers in two days! And WhatsApp saw the same spike with 112 new followers in a similar time frame. This represents some of the stepping stones in the overall rise towards the recent milestone of 500,000 followers.”

Vox Weather also offers a partnership with agricultural publications Landbouweekblad and Landbou.com, providing weather information to their readers. 

“We look forward to achieving our next milestones,” says Annette. “Each new broadcast and every new follower represents another step toward our mission: empowering  South Africans with accurate daily weather updates, as well as a more holistic understanding of weather patterns and their impact on the planet,” she concludes.

Beyond the Forecast – the Joys of Paragliding!

Annette and Michelle brave the skies – without an engine

 This Vox Weather story goes beyond maps and models to uncover a true-life story that’s shaped by the weather from start to finish – in this case, the fantastic experience of paragliding!

Vox Weather Meteorologists Annette Botha and Michelle Cordier decided to brave the altitude over Cape Town recently and experience the joys of paragliding for themselves. The idea was to go ‘beyond the forecast’ and learn how weather shapes this aerial sport, while also looking at the science behind good flying conditions.

Special thanks to adventure film maker, content creator and paraglider @MattAshwell, who flew with Annette and Michelle while giving commentary and explanations, as well as @SkyrideParagliding school for their first lesson.

Annette in the air!

Looking to the Skies

“People have been obsessed with the idea of flying for hundreds of thousands of years – and recently it was the turn of Michelle and myself!” says Annette.

“Here at Vox Weather, we thought it would be a fantastic idea to experience paragliding, as well as find out more about the important role of the weather in helping paragliders to get aloft and then stay airborne without the assistance of an engine.”

Michelle adds: “There are multiple stories about people in bygone years who didn’t only dream about flight, but actively attempted to fly by strapping birdlike wings or other devices onto themselves and jumping from towers – usually with very unfortunate results. As we know today, gravity is a force to be reckoned with!

“And so, for people to fly, they needed to find a way to overcome the force of gravity on body mass – in other words, people needed to find a way to create, or use, lift. This is a key concept in the sport of paragliding.”

Image courtesy of lithub.com

Let’s go deeper into how Annette and Michelle traded the studio for the skies, and find out how paragliders stay in the air for so long without an engine.

Image: Wikipedia

Weather’s Critical Role in Paragliding

After hiking up Lion’s Head in Cape Town to the take-off spot, the ladies first chatted to Matt and discussed what makes paragliding so special, as well as some of the science behind the sport.

“I think paragliding is one of the most weather-dependent sports out there,” says Matt, “and I generally start looking at the forecast two or three days in advance. The wind’s direction and strength are the two most important factors for any paragliding flight.”

Paragliders depend on thermals, which are rising air currents, to stay in the air for longer, without having to glide directly to the ground from their original height because of gravity’s effect.

 

“Paragliding is a three-dimensional sport,” says Matt. “You’re moving up and down in the atmosphere and the wind strength can change as you’re moving. And so it’s important to make sure that the wind is optimal where you take off and also higher up on your flight path, to make sure you don’t get blown away.

“I advise beginners to make sure that the thermals aren’t too strong on the day that you’re flying, so you don’t find yourself out of your depth with regards to the turbulence that you’re flying through.”

With regards to wind speed, he notes that the paragliders’ flying window is quite limited, at between about five and 25 kilometres per hour.

“Anything stronger, and you can’t fly because it’s too dangerous,” he explains, “and when it’s less, you can’t fly because there’s no lift. Besides the wind’s direction and strength, paragliders also look at the wind gradient, which is the increase in wind as you go higher in the atmosphere.”

And Now for a Spot of Science

Michelle explains: “Thermals, as Matt outlined, are critical to paragliders, allowing them to ride these rising air currents and gain altitude. Thermals form in different areas and at different strengths because the sun heats the ground unevenly. For example, dry fields and rocky hills heat up quickly and create strong thermals, while cooler areas like water and green fields create weak or no thermals.

“Paragliders also use specific graphs to see if flying conditions are good. A ‘Skew-T’ graph shows how temperatures and dew point – the atmospheric temperature below which water droplets begin to condense, and dew can form – change with height. This helps to plot where thermals can form.”

On the day that Annette and Michelle went paragliding, they experienced a weather phenomenon known as an ‘inversion’ (which had been anticipated, as per the forecast) and which prevented all those who were flying that day from going particularly high.

An inversion, in paragliding terms, means that at a certain altitude you find a band of air that is warmer than the air below and above it; this is an inversion.

Annette clarifies: “As seen in the graphics, we find that on a normal day, hot air continues to rise from the Earth, ultimately losing its heat and gradually becoming colder with atmospheric distance. With the creation of an inversion, however, we find a layer of warm air that traps the cooler air below it, preventing thermals from rising. This can limit a paraglider’s altitude and make it harder to stay airborne.”

Clouds often form an inversion for two reasons: firstly, because at an inversion the air mass changes characteristics, which often means that the combination of temperature and moisture is right to bring about the dew point; and secondly because the conditions attract the gathering of dust particles, which are necessary in cloud formation.

Matt adds: “We can clearly see how important weather forecasting is for paragliders, and we have a few specific options that we look at, including Windy and SkySight. Another very good site developed by a local guy is a weather forecasting site named RASP (Regional Atmospheric Soaring Prediction), which is what paragliders can use for very localised climatology in the Western Cape.”

Where Adventure Meets Atmosphere

There’s no doubt in Matt’s mind that paragliding is an addictive sport. He says: “The reason I’m hooked on paragliding is because of your ability to interact with the wind and be so high above the ground – and then of course the sensation of flying. To be able to do it so freely without an engine is just the best feeling ever!”

Annette adds: “We want to give Matt a huge shout-out for sharing his passion with us and showing us the skies from a different perspective – where adventure meets atmosphere!”

Stay tuned for more adventures ‘Beyond the Forecast’, where Vox Weather will explore how the weather shapes adventures across the country.

Climate Change and Weather Forecasting: Linking Science and People

Increased understanding helps communities prepare for extreme weather events

Climate change is affecting South Africans by significantly altering local weather patterns through higher temperatures, as well as the occurrence of extreme weather events. In fact, its impact in recent years has been so great that the government is planning to launch a national Climate Change Response Fund, which is intended to help pay for infrastructure to make South Africa more climate-resilient in the future.

This thinking reminds us of the importance of weather forecasting, both in the short term as well as over longer timeframes.

“While the planet’s climate has changed continually over the last 800,000 years through natural cycles and fluctuations, scientists have shown that human activity is driving our present spike in above normal temperatures globally,” says Vox Weather Meteorologist, Annette Botha.

“In particular, the burning of fossil fuels, such as coal, oil, gasoline and natural gas, has led to the ‘greenhouse’ effect, which is metaphorically and literally causing our planet to burn.” 

In this article, we discuss how the science of weather forecasting can provide a greater understanding of climate change, and thus help countries and communities around the world to be better prepared against the possibility of extreme weather events – as well as realising the critical importance of continuing the fight to reduce ‘greenhouse gas’ emissions.

Putting Climate Change Under the National SA Spotlight

As outlined previously, President Cyril Ramaphosa announced the implementation of the national Climate Change Response Fund (CCRF) during the February 2024 State of the Nation Address (SONA). The CCRF is intended to be a collaborative effort between the government and the private sector to fight against the increasingly devastating impacts of the climate crisis. 

During his announcement, President Ramaphosa noted the occurrence of devastating wildfires in the Western Cape, destructive floods in KwaZulu-Natal, intense heat waves in the Northern Cape, a persistent drought in the Eastern Cape and intense storms in Gauteng.

“While individual events like floods or fires cannot be solely attributed to climate change,” says Botha, “we are observing a broader trend: a steady increase in global temperatures and a rise in the frequency and intensity of extreme weather events. Climate is naturally variable, but human-driven warming is clearly shifting the baseline, making such events more likely and often more severe.”

Reduced water levels, Gamtoos Dam, Eastern Cape (Photo: The Herald)

Extreme Weather Events: Cause and Effects

Global warming has come about because of the increasing concentration of carbon dioxide (CO2) and other greenhouse gases – including water vapour, methane, nitrous oxide and fluorocarbons – that trap heat in the earth’s atmosphere and so cause a rise in global average temperatures.

Botha notes: “Because warmer air can hold more moisture, climate change results in more intense rainfall. As a result, because rainfall is increasing on average across the world, the chances of flooding are getting higher. On the other hand, climate warming also increases evaporation on land, which can worsen drought and create conditions more prone to wildfires. Added to this, the Earth’s warmer and moister atmosphere, together with warmer oceans, can create stronger hurricanes.

“Rising sea levels, which are partly caused by melting ice in the poles, increase the amount of seawater that is pushed onto shore during coastal storms, resulting in more destructive storm surges and flooding. The net result is that global warming is leading to more extreme weather events, and we have seen all of these climate change results in South Africa over the past few years.”

Lives are obviously at stake in the event of severe weather conditions if information isn’t available for warning purposes.

Botha notes: “Early warnings give people time to prepare against severe weather events like floods, tornadoes and lightning storms, whether that’s evacuating, securing property or staying indoors. Without timely updates, communities are left vulnerable, increasing the risk of damage, injuries and even loss of life.

“However, climate change is impacting on weather forecasting by altering weather patterns and increasing the frequency and intensity of extreme events, making long-term predictions more challenging.”

This is where technology comes in, to further back up the science of weather forecasting.

IBM Graf - weather forecasting via super computer

The Science and Technology of Weather Forecasting

Botha clarifies: “While short-term weather forecasts remain accurate, climate change introduces uncertainties in long-range predictions, due to shifts in climate variables like sea surface temperature and atmospheric circulation patterns. Scientists are developing new modelling techniques and tools to improve the accuracy of these long-term predictions.

“Meteorologists pull data from multiple sources including satellites, radars, weather stations and even high-altitude weather balloons. We also use global weather models and international meteorological databases. In South Africa, the South African Weather Service (SAWS) is a key provider of local weather data.”

Around the globe, high-performance computing (HPC) is crucial for weather forecasting today because it enables the efficient processing of vast amounts of data and complex mathematical models, leading to more accurate and timely predictions. HPC involves the use of multiple supercomputers to process complex and large calculations. This technology provides sufficient computational resources to improve the accuracy of short-term weather forecast systems models, with the aim of further reducing the severity of weather and climate related natural disasters. 

Linking People Through Technology

With climate change bringing more frequent and extreme weather events, platforms like Vox Weather are becoming even more important, says Botha.

“As South Africa’s first independent digital weather platform, Vox Weather delivers real-time, hyperlocal forecasts via social media and our website. We make weather updates engaging and accessible, and with close to 500,000 followers, we’re reaching more people than ever.

“We look forward to continuing to add information on climate change to our daily short-term broadcasts, as well as continuing to update our followers on the perils of climate change, and the ways in which both countries and individuals can play their role in helping to reduce greenhouse gases, in order to reduce global warming – for our future, and that of future generations,” she concludes.

Save Mother Earth... for future generations