Severe thunderstorms which wreaked havoc in Sydney have left about 21,000 homes and businesses without power with parts of NSW still copping a drenching.
The Bureau of Meteorology issued a severe thunderstorm warning with heavy rainfall, damaging winds and large hailstones forecast across northern NSW and the central west.
Wind gusts of up to 107km/h have been recorded at Coonamble in the central-western plains while winds reached 105km/h in Narrabri in the state's north west slopes, the bureau said.
Storms which lashed parts of Newcastle, Sydney and Wollongong earlier in the evening had eased by about 9.15pm prompting the cancellation of a severe thunderstorm warning, the bureau said.
During the storms more than 40mm of rain fell in 30 minutes in Auburn in Sydney's west.
Endeavour Energy emergency crews are restoring power to about 21,000 homes and businesses in the Blue Mountains and western Sydney after lightning and damaging winds lashed the areas.
Victoria on alert
Victorians are being told to watch for more flooding as the state gets deluged with record rains.
A flash flood warning was issued for Wangaratta, Byawatha and surrounding areas including the Hume Freeway on Thursday night and authorities are bracing for continued high water levels on Friday.
People are reminded not to drive through floodwater, after 120 people needed rescuing from the Hume Freeway south of Wangaratta, including 17 by helicopter.
Pedestrians walk through flood waters at the corner of Clarendon and Cecil Street in South Melbourne. Source: AAP
All up, 400-500 vehicles were impacted by floodwaters on the Hume Freeway, according to the alert.
More than a month's worth of rain has fallen across parts of Victoria and the wild weather is expected to continue through Friday.
Authorities spent Thursday rescuing people from car roofs after they got caught on the Hume Freeway south of Wangaratta.
"There's a certain degree of frustration, where people, after many, many warnings, continue to make the poor decisions, foolish decisions, in fact, to drive into flood water," Emergency Management Commissioner Andrews Crisp told reporters.
"They're putting themselves at risk, they're tying up emergency services unnecessarily. So - it's just - it's a dumb thing to do."
State Emergency Service Chief Officer Tim Wiebusch said authorities were taking the 120 people stranded from the waters to dry land, then in buses to the Wangaratta relief centre.
He said many vehicles, from heavy trucks to small cars, were caught in the waters.
Pedestrians walk through flood waters. Source: AAP
"It doesn't matter what the type of vehicle is, in these scenarios with the volume of water that was there - this wasn't a torrent of water that was all of a sudden just appearing in the roadway in front of people," Mr Wiebusch told reporters.
"People have foolishly chosen to drive through that flood water."
While most of the heavy rain in Melbourne is over, authorities say Victoria is not out of the woods and a severe weather warning remains in place.
Heavy rainfall and thunderstorms were predicted across the north of the state and the wild weather is expected to continue in coastal areas near the coast on Friday.
An almost stationary low pressure trough is over central Victoria and is likely to deepen into a low pressure system over the northwest overnight.
Across the state people are warned to be careful of rising rivers as floodwaters make their way through the system.
The SES is on alert for the Otways, South Gippsland and Wodonga in particular.
The service got 468 calls for help between 6am and 6pm on Thursday, including 225 for flooding and 124 for damage to buildings.
The Bureau of Meteorology says there's been record-breaking rainfall.
