Many have been commenting on how odd the weather has been across the Cape in recent weeks – it has shifted from sweltering heat to overcast with drizzle and sharp winds. As a result, it comes as no surprise to Capetonians that the SA Weather Service has released a weather warning for those on the coastline this weekend.
“A series of cold fronts passing south of South Africa generating large swells will reach the South African coastline from early on Wednesday morning. These long period swells will bring high energy to the coastline, peaking along the Western Cape’s west coast and Cape Peninsula regions. High wave energy will move eastwards from there, around the Cape south coast and weakening into the southern reaches of the Eastern Cape,” the service said in a statement.
“Long period – or powerful – swells of around 19 seconds are likely to be encountered along the west coast from 2am on Wednesday morning, spreading around the coastline, reaching the Cape Peninsula by 7am and the Cape south coast by midday,” it continued. “In each case, the onset of the long period swell will be followed by a steady increase in wave height. Significant wave heights ranging from 3 to 5 metres are expected between the Cape west coast and Cape Peninsula, dropping to around 2 metres for the Cape south coast.”
Slightly further offshore, wave heights may exceed 6 metres. Wave conditions will be accompanied by strong westerly to north-westerly winds, most notable for the south-west coastline. While wave energy should dissipate slightly by the evening of Friday, December 20, another system of powerful swell will reach the coast by the early hours of Saturday December, 21.
“In general, hazardous wave and wind conditions are expected to persist until Monday morning (December 23, 2019) for most of the Cape west and south coasts,” the weather service said.
Care should be taken to avoid a range of possible impacts associated with these sea conditions. Visitors to the coastline are advised to avoid low lying rocky coastlines and beaches experiencing big waves.
Beware of long lulls, followed by sudden large waves. There is a chance of waves breaking over coastal walkways and reaching further up the beaches than normal. Vessels operating along the South African west, south-west and south coasts should take care.
“Coastal users are encouraged to refer to detailed forecasts for specific areas of interest,” the service added.