While the foul weather in the Western Cape looks set to subside, the Eastern Cape should brace for a battering, forecasters warned on Thursday.

The SA Weather Service in Port Elizabeth has issued a severe weather warning, predicting heavy rain and severe thunderstorms in the region.

"Heavy falls, between 40mm and 55mm of rain, are expected along the coast and adjacent interior between Plettenberg Bay and Port Elizabeth today (Thursday) and tomorrow morning.

"Isolated severe thunderstorms can be expected over the interior eastwards of Cradock and Grahamstown, spreading to the south-east coast later in the afternoon," the PE Weather Office said in a statement issued shortly after noon.

The heavy rain was due to "a deep surface trough over the interior, a banana-shaped high and a deep layer of moisture", it said.

Earlier on Thursday, the Cape Town Weather Office said the fierce gales that have hammered Cape Town and other parts of the Western Cape over the past two days were subsiding.

"There is still rain forecast along the south coast for today (Thursday), with the possibility of heavy showers in the region between Helderberg and George," forecaster Lethando Masimini told Sapa.

The situation would improve on Friday, although there remained a possibility of more rain in this region, he said.

Gale-force winds and rain first struck the Western Cape on Tuesday night, ripping off roofs, flooding homes, closing roads, washing away bridges and damaging crops.

The scale of the damage in some Boland areas has prompted the Democratic Alliance in the region to call on Transport Minister Jeff Radebe for national funding.

"Abnormally high rainfall over the last two days has brought the rivers between Worcester and Romans River down in flood; washing away over 20 bridges and marooning thousands of people, mainly farm workers," DA provincial transport spokesperson Robin Carlisle said on Thursday.

Rivers had burst their banks, and there was wide-scale damage to vineyards.

"Three years of massive damage caused by flooding have exhausted the province's resources and flood damage funding. Only national [government] can assist with this new wave of flood damage, which will certainly not be limited to the Worcester area," he said.

The heavy storms have been blamed on a slow-moving low pressure system, which caused temperatures to drop and brought heavy rain. Called a "cut-off low" by forecasters, it was reportedly the strongest to hit the Western Cape in almost 30 years.

In Cape Town harbour, off-the-scale winds closed the harbour on Wednesday, a harbour official, who declined to be named, told Sapa.

Instruments which read and record wind speeds of up to 70 knots (almost 130 km/h), "went off the graph" several times between midnight and noon on Wednesday, the official said.

A spokesperson for Cape Town Disaster Management, Charlotte Powell, told Sapa on Thursday that damage in the Cape Town area from the storm included dozens of torn-off roofs, damage to vehicles from up-rooted trees and some localised flooding.

There were no reports of deaths or injuries, she said.

Sapa