Weather service confirms damaging landspout travelled 4.3km when cold front lashed Cape Town

The “indescribable sound” heard before a resident saw a nearby roof blown off when a well developed cold front hit Cape Town four days ago was caused by a wind phenomenon known as an EF-1 landspout. 

The SA Weather Service (SAWS) confirmed the winds that battered Cape Farms, near Morningstar Airfield, on Friday were caused by the phenomenon which rotates, in a similar fashion to a tornado, and is usually fast-moving and can be damaging. 

Landspouts are much weaker and smaller than a tornado and form from the ground up, while tornado vortices originate at the base of the parent cloud. 

The cold front made landfall early on Friday, bringing cold, wet and windy weather across the province.

“The wind phenomenon ... developed roughly 10km inland from Melkbosstrand near the Morningstar airfield (City of Cape Town District Municipality) in the Western Cape. Shortly after 10am, a resident recalled ‘an indescribable sound’ and noticed a nearby roof being torn off soon thereafter. The main damage included several corrugated roof sheets being blown off and informal homes blown over,” said SAWS.

“Based on the extent of the damage caused by the landspout, it was determined that it corresponded with EF-1 damage, utilising the Enhanced Fujita (EF) scale. In particular, the damage included an informal home blown over as well as a report by a community member of a securely installed and partially full JoJo water tank being lifted and blown some distance away.” 

Saws said the EF scale rated the intensity of the wind phenomenon by performing an estimation of the average wind speed, based upon the relative severity of wind damage to structures and trees.

The landspout developed near the Wolwerivier settlement at 10.08am as recorded by residents and moved eastward over the N7 main road, dissipating about 10.13am at the Olifantskop Farm. 

It travelled about 4.39km before dissipating. 

TimesLIVE