Australia Weather News

Winds sweeping South Australia have plunged thousands of residents into darkness again for another night only a day after the entire state suffered a blackout.

Destructive winds have been forecast to lash Kangaroo Island, Yorke Peninsula and South Australia's mid north while Adelaide appears to have "escaped the worst".

Earlier in the day, people in Adelaide were asked by police to leave work early if they were not performing essential duties as a precaution.

The Bureau of Meteorology (BoM) cancelled a warning for abnormally high tides late on Thursday night.

Water levels rose to 4.5 metres at high tide in Port Pirie in the evening,about 2 metres higher than the ordinary predicted lunar tide, but the tides began to decrease later on Thursday.

Bureau of Meteorology (BoM) forecaster Brett Gage said said the wind in Adelaide was expected to ease during the night while Kangaroo Island, Yorke Peninsula and the mid north would be lashed.

On Wednesday, the state was plunged into darkness after twin tornadoes that knocked out three transmission towers in the state's mid north.

Thousands of properties across South Australia remain without power due to ongoing outages.

There were also reports homes in the Adelaide Hills lost power during the evening due to storms.

SA Power Networks spokesman Paul Roberts said strong winds in Adelaide had reached 90kph, and 120kph on Kangaroo Island and Yorke Peninsula.

"I would expect we are going to see a mounting number of outages reported from the Adelaide Hills tonight and it's probably very unlikely we are going to get to all of those and restore power," he said.

Strong waves have also battered coastlines and caused damaged to the Port Rickaby jetty on Yorke Peninsula.

Port Broughton resident Kylie Thomas said several people had evacuated after high tide flooded houses and shacks on the Yorke Peninsula.

"The water was coming pretty much straight into the beachside door right down the side of the house and then into the carport," she said.

"It was just flowing like a river. The waves were just crashing up against the house, like the front verandah was just a beach so it was pretty horrible to see that."

SES chief officer Chris Beattie warned that if the weather event hit Adelaide, SES crews would be "stretched beyond capacity" but Victorian crews were on standby to help.

An SES volunteer injured on Wednesday night and taken to Flinders Hospital with minor injuries has since left hospital.

Flood warnings issued statewide

A flood warning has been issued for a number of rivers across South Australia as the Bureau of Meteorology (BoM) warns waters are rising rapidly.

This includes the Light and Wakefield rivers in the Mid North, where waters are rising and are expected to remain high Thursday and Friday.

The bureau said the Wakefield River at Rhynie was the highest it had been since September 2010 and further rises were expected.

A generalised flood warning was issued for the Angas and Bremer rivers in the eastern Mount Lofty Ranges, where the bureau said water levels had also "risen rapidly ... in response to rainfall in the last 24 hours".

"Rainfalls in excess of 60 millimetres have been recorded in the 24 hours to 11:00am Thursday in the Bremer and Angas catchments," the bureau said.

BoM said flooding could occur along both rivers, particularly downstream of Willyaroo and Wanstead Road and Lanhorne Creek.

There was also a flood emergency warning issued for Lyndoch, with water levels continually rising in the Lyndoch Creek.

Flooding hits Clare as waters rise ahead of worsening conditions

Roads and footbridges in the town of Clare in South Australia's mid north have been flooded in the wake of the Hutt River bursting its banks.

The SES' Mr Beattie said the town was at risk of isolation and the community had been warned.

Police said the township and caravan park had been impacted and urged people living or travelling through the region to closely monitor conditions.

Patrick, who lives just north of Clare, told 891 ABC Adelaide the Hutt River had burst its banks and was running over the over Horrocks Highway.

"I see the police are there and I'm about a kilometre from where it has burst and the river is busy running down my driveway at the moment," he said.

Clare Valley Winemakers chief executive Tanya Matz said "patches of roads" in the region had been washed away, including at nearby Penwortham.

Ms Matz said vans at the caravan park had been moved to higher ground at the showgrounds.

The SES advised that a dam east of Sevenhill in the Mid North was in danger of collapsing due to the recent heavy rain.

"There is a risk that the dam will burst and cause flooding of properties and roads in the Sevenhill Township," it said.

A flood watch and act message was issued for Auburn due to a dam threatening to burst north of the township.

BoM said there was a moderate flood warning for the Onkaparinga River in the Adelaide Hills and south of Adelaide, which caused widespread flooding two weeks ago.

There was also a moderate flood warning for the Torrens River.