A tornadic event – South African Weather Service explains

The South African Weather Service (SAWS) confirmed the natural phenomenon that ripped through Toekomsrus and Mohlakeng on the afternoon of November 27, was indeed a tornado.

According to forecasters Puseletso Mofokeng, Luthando Masimini and Lehlohonolo Thobela, SAWS can confirm, from evidence gathered from meteorological Radar, that the storm damage and recorded circulating debris in the Randfontein area on November 27 was due to a tornado event.

They further explained that SAWS issued a level two warning for severe thunderstorms that morning.

• Also read: Aftermath following Mohlakeng natural disaster

“Based on the analysis, the storm can be rated as an EF2 on the enhanced Fujita scale. The impacts of this storm resulted in the damage of a vehicle which seemed to have been hit by a solar panel from a roof, and roof sheets being torn off and peeled at the corners of the buildings across a relatively large area,” their statement read.

• Read the initial article here: Child rushed to hospital after wall collapses during tornado

They stated a thunderstorm marked X in Figure 1 moved to the east, across Randfontein between 12:30 and 12:45. Another storm marked Y in Figure 1 then blew the cold air (outflow) from the first storm to the north of Randfontein. The V-shaped valley then channelled this air.

“Due to the channelling by the valley, this outflow rapidly and significantly strengthened, connecting and intensifying the storm, marked X.

“The interaction of this stronger gust front with the thunderstorm which moved across Randfontein triggered the ground-up rotation, which later supported the development of a tornado. Based on the analysis, the storm can be rated as an EF2 on the enhanced Fujita scale.”

Preliminary reports indicated that 21 injured people were transported from Umphakathi Mall. Further damage includes roofs and a vehicle that was believed to have been struck by a solar panel from a roof.

The statement continued that in a SAWS study done from June 2016 to June 2021, it was established that 76% of tornadoes developed from the interaction between the strong gust front of an upwind storm with a downwind thunderstorm.

“Tornadic events are part of severe thunderstorms, but weather models have difficulty in predicting them due to their small size in comparison to that of the models. These events can be picked up with Radar technology but at a very short lead time. The SAWS is exploring incorporating emerging technologies such as artificial intelligence, machine learning, and other technology to enhance its forecasting capabilities.”

They added precautions that can be taken when a tornado is approaching:

• In the event of seeing a tornado, move to the pre-designated building and then move into the smallest room, or get under a strong piece of furniture, such as a table.
• Get out of vehicles, caravans and mobile homes, as they can be moved, overturned and even destroyed by the strong winds and flying debris.
• Stay away from windows as flying glass and debris cause the most deaths.
• Do not attempt to outrun a tornado in your vehicle. Leave it immediately and seek shelter.
• If caught outside in the open, lie flat in a ditch or depression but beware of flooding if there is heavy rain.

They concluded in respect of the short-term forecast no further severe thunderstorms are expected for Gauteng from November 28 through the weekend.