Understanding Severe Storms in Cape Town: A Climate Research Perspective

A severe storm recently struck the Western Cape province of South Africa, causing significant destruction in Cape Town and surrounding areas. Tragically, over 1,500 individuals lost their lives in the aftermath of the storm due to fires ignited by high winds that engulfed their communities.

Climate researchers, Sabina Abba Omar and Stefaan Conradie, renowned for their work on climate patterns around Cape Town, shed light on the unique climate of the region. Cape Town stands out as the sole winter rainfall area in southern Africa, contrasting with the predominant summer rainfall in other parts of the region.

In the winter months, Cape Town experiences cold, wet, and windy weather brought by westerly winds. This weather pattern is often accompanied by ‘cut-off lows,’ upper-atmosphere weather systems known to move slowly and deposit substantial rainfall in localized areas.

Unlike the more common cold fronts, cut-off lows can form at any time and are usually associated with south-easterly winds in the Cape Town region. They can induce the ‘Black South-Easter,’ a meteorological phenomenon where dark clouds are ushered in by the usually fair south-easterly wind.

Recent years have seen a series of severe weather events in the Cape Town region, including heavy rains in 2022 and 2023, leading to flooding and landslides. In 2023, Cape Town witnessed the highest rainfall on record since 1893, brought about by cut-off lows and atmospheric rivers.

Research on the connection between these extreme storms in Cape Town and climate change remains inconclusive. While global studies have linked climate change to increased precipitation in various regions, the impact on Cape Town’s weather patterns is not definitive.

Despite expectations of a warmer and wetter future for the region, uncertainties persist regarding future storms and their intensity. The Climate System Analysis Group at the University of Cape Town continues to explore these complex climate dynamics.