Kevin Scott
It will always influence you. No one can avoid it, some have even worshipped it, and whether you hate it or love it depends on your location. Good or bad, there’s no argument that the weather always serves as an excellent conversational gambit. And so it’s no surprise that Mnikeli Ndabambi, deputy director of the South African Weather Service, is not short of conversation pieces.
A specialist in short-term forecasting, Ndabambi has dedicated his research to improving gale-force wind predictions so that warnings can be issued, in order, he says, to save lives. “Gale-force winds result in the sinking of ships and boats, the destruction of buildings and flying objects, all of which can be fatal,” says Ndabambi.
One needs only to look at the ill-fated Oceanos cruise liner, he says, to see devastating results of weather. In August 1991, battered by rough seas and howling winds, the Oceanos sunk off the Transkei coast. “This demonstrates typical rough sea conditions and their impact on human activities,” he says. Despite atrocious weather conditions, one person swept into the water was kept alive by the warm Agulhas current that runs south-westerly down the Transkei coast a sign of how ironic weather can be and was among the 330 passengers and crew who were rescued.
Working from Pretoria, Ndabambi uses numerical weather-prediction models to reconstruct weather patterns using information collected from stations around the country. “The interesting thing about weather is that you learn each and every day,” he says. “It’s never boring at all.”
Using pressure and temperature gradients, analysing the movement of pressure systems and the rate of wind divergence in the upper atmosphere, Ndabambi wants to create a model in which meteorological indicators can be used to predict winds accurately. “The forecaster needs to be able to associate various parameters with specific wind strength,” he says.
Looking at a small area along the Cape south coast stretching from Cape St Francis to Port Elizabeth, Ndabambi has selected four case studies to observe wind and weather patterns. This, he says, will help researchers understand the complexities involved in weather predictions and assist him in producing a model for reliable detection of gale-force winds. “My research looks at forecasting techniques which can be better used as guidelines when predicting gale-force winds,” he says.
Ndabambi says the Oceanos disaster was caused by “a deep low-pressure system with a very steep-pressure gradient”. Low-pressure cells are pockets of air with a relatively lower atmospheric pressure than the air surrounding them. When the pressure difference is significant, a steep gradient is formed and a gale-force wind ensues which generated the high waves that battered the doomed ship, Ndabambi says.
The south-eastern seaboard of South Africa is notorious for its freak waves. On the day of the Oceanos disaster, says Ndabambi, the south-westerly flowing Agulhas current came into contact with a north-east flowing swell, a major reason for the giant waves.
Besides being fond of talking about the weather, Ndabambi wants to include everyone in the science behind it all. It is important for him to “share the most challenging and interesting atmospheric dynamics” of weather forecasting. “This includes ordinary people who might not be scientists, but can experience and see the outcomes of atmospheric behaviour.”
This will help people become aware of dangerous weather conditions. “People should take note of severe weather warnings issued by the South African Weather Service,” Ndabambi says. “This way they can avoid the affected areas. For example, fisherman should move out of the sea before the arrival of gale winds. People should stay in shelters when severe storms are expected especially bearing in mind that a severe storm is accompanied by destructive hail.”
Weather is a constant changing entity, something drawing Ndabambi to it. “I can’t wait to see what changes are coming for the future.”
To say Ndabambi loves his job is an understatement. He lives it.
Mnikeli Ndabambi will be hosting a talkshop at the Monument Bridge on March 14 at 2pm. The topic will be Gale Force Winds Along the Southern Coast and Associated Dangerous Conditions