WATCH | Warning of high waves, flooding
A shipping warning of large rogue waves capable of damaging ships and flooding coastal areas was issued by the SA Weather Service on Tuesday.
Saws also announced that the Eastern Cape had been hit by a storm surge on Monday night.
Saws Port Elizabeth spokesperson Garth Sampson said: “Abnormal waves are possible in the Agulhas current between Port Alfred and East London from Tuesday afternoon until Wednesday morning, possibly causing coastal inundation.”
He warned that the abnormal waves were capable of causing damage to vessels and would affect coastal recreational activities.
Sampson said three weather factors had combined to cause the surge. These were a spring high tide, high seas and strong westerly winds.
The extra-high tide was caused by the gravitational pull of a new moon.
He said videos were being shared widely of flooding of roads in Port Elizabeth’s Amsterdamhoek on the Swartkops River and in Port Alfred, where CBD parking lots were under water.
East Londoners posted pictures of water entering the Gonubie River spreading along the grass towards the Gonubie Marine Club.
At the Orient Beach, the water lapped against the buildings housing the lifesavers’ tower and covered seating area.
A video posted to Facebook by Talk of the Town shows the Equinox spring tide flooding the Port Alfred CBD on Tuesday.
Sampson said: “Though it is relatively rare, it is the first time, other than during floods, that I have seen the roads in Amsterdamhoek flooded.”
He said that had the winds turned onshore, and blown from the sea to land, more streets, among them the N2 running along the PE shore, would have been covered by the sea.
This happened during the last big surge on September 1 2008 when the sea rose dramatically on a windless day, breaking pot plants on the decks of mansions on the Kowie River.
Sampson said Monday’s surge had been caused by a cold front bringing gale force winds, which drove the open ocean swell up to 9m high.
“Simultaneously there was a spring high tide which further enhanced the wave heights and resulted in a storm surge along the coast between Plettenberg Bay and East London.
“The forecasters on duty managed to issue a threshold warning for both the gale force winds and a high seas warning for the public on Sunday, while a wind and wave affect-based warning was sent out to the relevant municipal officials on the same day.”
He said the special conditions were expected to start subsiding from Tuesday night but wave heights were still expected to be between 4.5m to 5.5m on Wednesday.