PICS: 'Tornadoes are not uncommon in SA'
Tokelo Chiloane said tornadoes occurred during severe thunderstorms which included strong winds.
She said it seemed that tornadoes were becoming more common now, but this was possibly because people now had cellphones to record such incidents and share them. But the truth was that they had always occurred in the country.
Chiloane said tornadoes would often strike parts of the Free State and no one would know because there was no one to record it.
Farmers in those areas often complained of livestock being killed by tornadoes.
The lifespan of a tornado was between three to five minutes, said Chiloane, adding that South African tornadoes differed from tornadoes that occurred in countries like the US, where they could last for hours.
This was because the dynamics in South Africa and the southern hemisphere were different to those of the northern hemisphere. One of the conditions that differed was the wind direction.
In the northern hemisphere, the wind direction in tornadoes was anti-clockwise, while in the southern hemisphere it was clockwise.
Another characteristic was that tornadoes in the southern hemisphere had warm air coming from the equator and cold air coming from the South Pole converging, and South Africa was in the middle of these two air currents, said Chiloane.
She said the weather service had issued an alert for severe thunderstorms for the eastern, central and northern parts of KwaZulu-Natal, lasting until tomorrow afternoon. She said there was a chance of flooding along the entire coast. This was due to a passing cut-off low - or low-pressure weather system - which was expected to have left the country by Friday afternoon.