EF0 Tornado observed on Heilbron farm in Free State

A tornado was observed on a farm near Heilbron between 15:00 and 16:00 on Monday, the South African Weather Service (SAWS) confirmed. Forecaster Lehlohonolo Thobela said the tornado occurred during a period of severe thunderstorms in the area.

“There were gusts around the region, with identified shearing, convergence, and moisture to form a convective cloud, which resulted in a supercell later in the afternoon. Conditions were favourable for a tornado to form,” Thobela explained.

SAWS research shows that tornadic activity is most common in South Africa’s Highveld, Free State, Mpumalanga, and KwaZulu-Natal regions. Historically, tornadoes in the country occur between November and March, though documented events have also been recorded in spring months such as September and October.

The formation of tornadoes is typically linked to warm, moist air colliding with cooler triggers, along with low-level wind shear and unstable atmospheric conditions. Recent studies on the Highveld indicate that supercells in the region during the early convective season particularly in October and November can last around 1 hour and 12 minutes, moving at an average speed of 41 km/h and covering roughly 49 km. Topography may also influence the path and development of these severe cells.

According to SAWS, the Heilbron tornado caused no reported damage, as it passed over open farmland. The event has been classified as an EF0 tornado on the Enhanced Fujita Scale, with estimated wind speeds between 105 and 137 km/h. EF0 tornadoes typically result in minor damage, such as broken tree branches or light roof damage.

“While EF0 tornadoes are relatively weak, they remain dangerous weather phenomena. The public is urged to exercise caution during severe thunderstorms,” Thobela said.