ALERT issued for negative STORM surge – these areas will affected [Video]

The South African Weather Service (SAWS) issued an alert for a negative STORM surge for Tuesday and Wednesday.

THE ALERT FOR THE A NEGATIVE SURGE WAS ISSUED FOR TUESDAY AND WEDNESDAY

The negative surge is likely to affect the South African west, south-west, southern and south-east coast.

ALSO READ: WARNING: Winds of up to 65km/h are expected in parts of SA

“The SAWS forecast system indicates that sea levels may drop below chart datum at times of a low tide between Saldanha and Gqerbha, including Ngqura. The effect will be most pronounced at Mossel Bay where sea level could drop 20-to 25cm below chart datum during low tide.”

SAWS

It furthermore issued a yellow level 2 warning for damaging winds in Gansbaai and Alexander Bay Strong south-easterly winds that will cause very rough and choppy sea conditions.

Alert for negative surge over South Africa – 29 – 31 August 2022 pic.twitter.com/RCtfY1pw1A

— SA Weather Service (@SAWeatherServic) August 29, 2022

WHAT IS A STORM SURGE?

According to Annette Botha, VoxWeather forecaster, a storm surge is a rise in sea level caused by a storm. They can cause extensive flooding and are hazardous to residents of many coastal areas.

ALSO READ: More SNOW is expected on TUESDAY in several parts of SA

🌊A negative storm surge and dust storms🌊??

Meteorologist Annette Botha explains the weather warnings and NEGATIVE STORM SURGE ALERT issued by SAWS

[A THREAD] pic.twitter.com/mZ1Ske9Fom

— Vox Weather (@VoxWeatherZa) August 30, 2022

WHAT CAUSES A STORM SURGE?

The main cause of a storm surge is high winds pushing the seawater towards the coast, causing it to pile up there.

“There is also a minor contribution from the storm’s low pressure, which “pulls” the water level up by about 1 cm for every 1 millibar change in pressure.”

Annette Botha

WHAT IS A NEGATIVE STORM SURGE?

Botha said a negative storm surge could also occur when the wind direction blows the water away from the coast, or off-shore during low tide, causing the sea level to fall.

“These are less dangerous than positive storm surges because they do not cause flooding, but they can damage ships in ports and leave them stranded until the water level rises again.

“The height of a storm surge depends on many factors such as the size and strength of the storm, the direction it approaches the coast and the shape of the coastline and seabed.”

Annette Botha

Meanwhile, snow was confirmed on Tuesday in several parts of South Africa. There is more cold weather and snow expected.

Click here to LOOK at the snow photos.

Did you take photos of the snow? We would love to see your photos. Send it to corne@thesouthafrican.com and please remember to include your details.

According to the South African Weather Service (SAWS) the snow started on Monday afternoon and will continue until Tuesday morning.

Light snowfall is expected in the high-lying areas in parts of the Eastern Cape, Western Cape, KwaZulu-Natal, as well as Lesotho from late on Monday afternoon.