A large cold front colliding with a warm and humid airstream coming from the north is delivering prime conditions for wild storms.
Severe weather, hail and flash flooding hit parts of South Australia overnight, with wind gusts of more than 130km/h recorded at Port Pirie and Roxby Downs, and a 36mm deluge in one hour reported at Mount Horrocks.
While things have begun clearing in and around Adelaide, more than 5500 South Australians were still without power on Friday morning, down from around 20,000 overnight, as the wild weather continued eastward.
"The risk of thunderstorms will be widespread in the east, from southern Queensland through NSW, Victoria and into northern Tasmania." senior Bureau of Meteorology forecaster Miriam Bradbury said in an update.
There was also a risk of storms in parts of inland Queensland and the Northern Territory, but these were unlikely to bring much rainfall, she said.
Severe storms were most likely across NSW's central and southwest slopes and in northeast Victoria, potentially bringing giant hail and damaging winds in excess of 125km/h. "In the interim, back-up generation and business continuity plans are in place."
In western NSW, extensive damage to transmission towers during recent storms left more than 1400 residents without power in and around Willcannia, while back-up generators were powering customers in nearby Broken Hill.
More than 3000 Victorians were without power on Friday morning.
Casterton, in Victoria's west, was struck on Wednesday afternoon by what some locals called the worst storm they had encountered.
Victoria's State Emergency Service took more than 100 calls, with at least 70 relating to building damage or flooding.
Flood watch warnings could be issued in the coming days, but the front itself is expected to drag the severe weather offshore by Saturday afternoon.
"Southern Victoria, Tasmania and eastern NSW will see easing showers during Saturday, with gusty southerly winds," Ms Bradbury said.
The wild weather is expected to ease in eastern and southeastern Australia by Sunday for a mostly dry and relatively sunny close to the weekend.
With AAP.
Image: AAP
