Australia Weather News

Worsening weather conditions have caused more blackouts across South Australia, as emergency crews continue to grapple with yesterday's state-wide blackout.

Premier Jay Weatherill said twin tornados ripped through the centre of SA, damaging critical infrastructure and shutting off power to the entire state.

The storm, billed by the Bureau of Meteorology (BOM) as a once-in-50-years event, also tore roofs off buildings and brought down trees and powerlines.

By the early hours of this morning, much of Adelaide's power had been restored.

But SA Power Networks relations manager Paul Roberts said more wild weather had seen a further 10,000 customers lose power this morning, including some Adelaide suburbs.

Some power was restored during the morning, but tens of thousands of properties are still without.

The Australian Energy Market Operator said the root cause of yesterday's state-wide outage was likely due to the multiple loss of 275 kilovolt power lines during the storm.

"These transmission lines form part of the backbone of South Australia's power system and support supply and generation north of Adelaide," the statement said.

"The reason why a cascading failure of the remainder of the South Australia network occurred is still to be identified and is subject to further investigation."

More wild weather is on the way, with an intense low-pressure system expected to cross the state today and a severe weather warning in place for most areas.

Gale-force winds are expected across the state, reaching speeds of 50 to 75 kilometres per hour with gusts of 90kph to 120kph.

Damaging winds gusts of 90kph to 115kph and winds averaging 50kph to 65kph have been recorded at multiple locations including Ceduna, Coles Point, Port Lincoln, Minlaton, Kadina, Woomera and Mount Crawford.

The conditions will cause sea levels to be significantly higher than indicated on tide tables today.

Sea levels along parts of Spencer Gulf and Gulf Saint Vincent coastlines are likely to be about one metre higher than the highest tide of the year, particularly in the Spencer Gulf.

At the Outer Harbor tide gauge, the sea level is forecast to reach about 3.4 metres to 3.8m, which may cause sea water flooding of low-lying areas.

The high sea level and windy conditions will combine to generate heavy surf along exposed gulf coastlines, which may lead to coastal erosion and damage.

Significant rainfall still to come: BOM

BOM has also forecast heavy rainfall, which could cause flooding, in areas including the Mount Lofty Ranges.

BOM regional director John Nairn said there was still a significant amount of rainfall to come over the next few days.

"My advice to the state is that certainly we have seen probably half the rain that we were expected to see so far through this event," Mr Nairn said.

"We are expecting quite significant falls through the latter part of the evening and toward midnight.

"Apart from that, we will see conditions moderate through Friday, it will still continue to shower.

"A fine day Saturday, thank goodness, however we do know that we will see rain recommence through Sunday, Monday and Tuesday."

A minor flood warning has been issued for the Onkaparinga River, Angas and Bremer Rivers and a flood watch is in place for the Mount Lofty Ranges and Adelaide Metropolitan Districts.

A number of road closures are in place across the Greater Adelaide area, including Strathalbyn Road at Aldgate, Gorge Road and the Verdun exit near Hahndorf.

'Difficult to predict when power will return'

Mr Roberts said damage to transmission infrastructure and the ongoing storm was making it hard to predict when all power would be restored.

"We've still got more weather coming in so it's very difficult to give you categorical information on when people will be restored and what might pan out today."

A family of six escaped injury after a tree crashed through the roof of its Aldgate home last night.

The home was extensively damaged and both the CFS and SES attended.

A member of the family said they were fortunate to have a rental property in Stirling that was vacant.

They will move there while repairs are made.

Police said some landline and telephone services were still down in parts of the state.

Schools, shops and petrol stations in the Mid North are mostly closed.

Damage to power infrastructure unprecedented: Weatherill

Mr Weatherill said there was nothing that could have been done to prevent the entire state from losing power during the wild weather.

"I've been in contact with the head of the Australian Energy market operator said he said to me that any system couldn't cope with a weather event of this sort," he said.

"I mean we had winds which were so strong that when they hit powerlines they were creating such energy they were tearing their towers out of the ground.

"This is an unprecedented event. Nobody has seen such a catastrophic failure of so much major infrastructure in any other part of the nation, and so that's our advice from the Australian Energy Market Operator."

Adelaide Airport is fully operational although some flights have been cancelled.

The Department of Transport said trams, trains and buses should be running as normal in Adelaide today, but has warned commuters to be prepared for delays.

Around 18,000 State Emergency Service (SES) personnel were on standby to help clean up after the storm, including teams flown in from Western Australia.

The SES's Terry Dwyer said workers had responded to nearly 1,000 call outs since the storm hit the state yesterday.