As parts of the Western Cape grapple with the aftermath of a destructive weather system that tore off rooftops and submerged roads, Daily Maverick spoke to experts who explained what happened and why it may happen again.

Over the weekend in the Western Cape, nature's fury was unleashed with seemingly unprecedented intensity, with rooftops ripped off, roads submerged and communities cut off from the outside world. In what is almost certainly the wettest year in the province's recent history, the Heritage Day weekend saw more rain in three days than in the previous two months.

But what exactly caused all of this and how normal or abnormal is it?

In conversations with Daily Maverick, Dr Peter Johnston, a climate scientist and research officer at the University of Cape Town's Climate System Analysis Group (CSAG) and Kate Turner, a forecaster at the South African Weather Service (Saws) explained why the Western Cape was rocked by wet and windy weather.

A 'cut-off-low'

The Saws, after issuing an Orange Level 9 warning, explained that from Saturday night, a "cut-off low-pressure system" -- the equatorward displacement of a low-pressure system at high altitudes -- developed along the west coast of South Africa. That system intensified by Sunday as it entered the country's western interior, causing bursts of intense rainfall, flash flooding, strong winds and very rough seas.

A cut-off low is a "type of weather system that develops in the...