Fury of severe thunderstorm brings despair
NOMSA Makama is packing furiously. She throws heaps of clothes and toiletries into a bag alongside her dishevelled bed. She and her family haven’t slept at home since Monday and now, they have to quickly pack up everything and leave their one-bedroom flat for good.
“It’s not safe to be here,” says Makama, looking worried. “We’ve been told that if we stay, it’s at our own risk.”
But still, the family count themselves lucky. The 29-yearold opens her bathroom door to show the damage from Monday’s severe thunderstorm: it was a reported tor nado, she believes, that ripped the roof off her bathroom.
“That was the worst we experienced but the rest of our flat is okay. Our neighbour’s whole flat was damaged while the children were there.”
“But we’re lucky, the people in the informal settlements suffered far worse,” interjects her partner, Thabo.
Other than the clang of machinery from the army of repairmen fixing broken roofs, there’s a ghostly silence at the Wedge Complex in Honeydew, Joburg, destroyed by the massive thunderstorm.
That’s because most of the occupants are staying with relatives.
The ruins of broken roofs, collapsed walls and downed trees are strewn across the complex.
“Our nanny, who was at home with our nine-monthold baby, Tsiamo, called us in a panic on Monday. But there was nowhere she could go. She just had to stand and wait for the storm to pass. Luckily, they were okay.”
The severe thunderstorm, which tore through parts of Gauteng, Mpumalanga and KwaZulu-Natal this week, claimed several lives as it destroyed homes, schools and hospitals.
The SA Weather Service has classified it as a “supercell thunderstorm”, the most intense type of thunderstorm, defined by deep rotating up-drafts, heavy downpours, strong damaging winds and large hail.
Tornadoes, it says, caused extensive property damage.
“There’s no one you can blame,” says Makama, soberly. “You can’t make Mother Nature pick up the bill for all the dam- age.”
Dr Johan Malherbe, a senior researcher in climate studies, modelling and environmental health at the Council for Scientific and Industrial Research (CSIR), explains this cut-off low system.
“In general, if flooding or widespread storms occur over the summer rainfall region during spring, it’s most of the time associated with this type of weather system. It’s not exclusive to spring, but relatively more prevalent, with another peak during autumn.”
Professor Francois Engelbrecht, the research group leader and chief researcher of climate studies, modelling and environmental health at the CSIR, agrees.
“Cut-off lows occur over South Africa as part of the country’s natural variability in climate, and they occur most frequently in spring and autumn. The recent event is therefore not atypical at all, and there’s no reason to think this specific event was a consequence of climate change,” he says.
However, Engelbrecht points out that there is evidence that the frequency of intense thunderstorms over the Highveld have been increasing in recent decades as a consequence of regional climate change.
“Most climate change models are also projecting that, as the planet continues to warm, the central and eastern interior regions of South Africa are likely to be affected more frequently by intense thunderstorm events.
“This means we will have to deal with the increasing impacts of damaging winds, hail, lightning and flash floods, which all occur in association with intense thunderstorms,” adds Engelbrecht.
Research published by the CSIR, Agricultural Research Council and University of Pretoria in 2013 indicated that cut-off low events may occur less frequently over South Africa under enhanced climate change, he says.
“This is because these systems are a part of the so-called westerly wind regime, and this circulation region of the planet is projected to migrate polewards as the planet warms.
“As a consequence, cold fronts (which bring rainfall to the south-western Cape and the Cape south coast) as well as cutoff lows are projected to make landfall over South Africa less frequently.”
Engelbrecht adds that CSIR research for the Water Research Commission indicates a potential benefit of these storms for South Africa.
“In the mega-dam area of eastern South Africa, the i ncreased occur rence of intense thunderstor ms may lead to enhanced run-off and stream flow into the big dams.
However, such an increase in intense rainfall will also result in enhanced soil erosion and sedimentation in the mega dams, so that it is not fully clear whether enhanced stream flow will really benefit the country in ter ms of enhanced water yield.”
This week, SA Weather Service chief executive Jerry Lengoasa stated how it had “reflected” on its response to extreme weather events and its efforts to warn South Africans to save lives. “Thunderstorms (are) predictable in advance as severe weather systems, but their rapid evolution (means) the lead time available to issue warnings is limited.”
While its observation infrastructure was operational this week “some of the most important stor m monitoring tools like the Durban radar were not operational at the time of need because of a system breakdown”.
He says R30 million is needed urgently to improve communication “before the end of the summer season, noting that up to 80% of disaster risk management financing and expenditure is often focused on response and recovery and not on early warning systems, of which the weather service is a key and strategic part”.
Dr Elias Sithole, Gauteng’s head of disaster management, says its assessment shows the damage “runs into the millions of rand”.
“Sometimes, we find the drainage systems are blocked. We have to work with municipalities and you find maybe they haven’t been cleaning the drains for some time. We have the capacity to respond to these incidents. However, because some of the departments end up dragging their feet, this ends up complicating the responses to be more effective.
“But there is greater willingness. I’m pleased because we were much better prepared to deal with this event compared to previous years.”
The City of Johannesburg says its disaster management department has completed a severe weather risk assessment and compiled a risk profile of Joburg, identifying low-lying areas and vulnerable areas.
“The main challenge ... is development that leads to disasters through poor planning and a lack of funding for disaster risk reduction measures in all departments.”
Bertha Scheepers, of the Joburg Roads Agency, says it is addressing stormwater issues through stor mwater master-planning, a blueprint for solutions to flooding problems from inadequate or non-existent stormwater infrastructure.
This is the most effective method to “address the current drainage challenges and also avoiding a recurrence of the same challenges in future by providing an effective drainage plan in advance.”