The two tornado-like whirlwinds that were spotted in Gauteng on Wednesday were mere "gustnadoes", according to the South African Weather Service.Images and videos of the incident were shared on social media, with users questioning if it was, in fact, a tornado. It is believed to have occurred in the Bapsfontein area.SAWS forecaster Wayne Venter described these wind funnels as gustnadoes, a specific type of dustdevil that develops along a gust front of a thunderstorm."The absence of any radar signatures strongly suggests that the vortices in the eyewitness video were not tornadoes," said Venter."A tornado is a rotating column of air, extending from the base of a cumuliform cloud and is often visible as a condensation funnel in contact with the ground," he said, adding that the sightings in Gauteng showed no signs of a condensation funnel and no visible rotation in the cloud base.Last week, KwaZulu-Natal was hit by a severe thunderstorm that produced two tornadoes which killed two people and injured nearly 20.Over the past 10 years, 16 other tornadoes have been recorded, SAWS spokesperson Hannelee Doubell told News24 last week.Tornadoes were not such an uncommon phenomenon, Doubell said, especially in the KwaZulu-Natal Midlands and Eastern Cape, where they occur quite frequently."The maximum wind speed of a tornado is usually between around 120 and 360km/h, but can even be stronger than 432km/h. The pressure in the funnel is considerably lower than the surrounding atmospheric pressure," Doubell said.