Inland heat and moisture combine as damaging thunderstorms sweep across the south and east.

More than 21,000 homes were without electricity in Mildura, Victoria on Friday after a lightning storm ripped through the area, tearing down trees and power lines. There were also reports of a mini-tornado damaging buildings.

The storm hit in the evening and continued throughout the night in Merbein, Mildura and Red Cliffs, all border towns on the Murray river.

Mildura received 29mm of rain in 15 minutes on Friday evening as winds gusted to 100 kilometres per hour at Mildura Airport. Locals took photos of the golf ball-sized hail that fell from the sky.

It has been hot in central Australia over the last few days, despite cooler air from the Great Australian Bight blowing in. The hottest place in Australia on Friday was Leigh Creek in South Australia at 42C. But on Saturday it was knocked back to 27C.

This big change in temperature as the wind swept through has created a cold front, generating thunderstorms across the heart of Australia, which have moved east. These joined an arcing trough line, stretching from the Spencer Gulf, west of Adelaide, up to Alice Springs.

The resultant line of major thunderstorms swept across South Australia, Victoria, New South Wales, ACT and most recently Queensland.

Adelaide was smashed on Friday by hail the size of golf balls and felt a drop in temperature of at least 10 degrees Celsius.

Thousands of properties were left without power in Broken Hill, in far west New South Wales (NSW). Golf ball-sized hail and severe winds caused widespread damage to property and trees, and battered homes and vehicles.

Local resident Ken Holden said the wind was throwing the hail in all directions. “By gee it was powerful, it was being pushed by some very, very, very powerful gusts, I would say some of the strongest weather I’ve ever seen in Broken Hill.”

The storms eased a little overnight but regenerated on Saturday.

Up on the Darling Downs in southern Queensland, west of Brisbane, Oakey recorded a wind gust of 85 km/h and there have been reports of extensive damage around Condamine Plains.

In Brisbane, flights were diverted or delayed because of Saturday afternoon’s wild storms, which took out the runway lights at Brisbane Airport. More than 70,000 lightning strikes have also been recorded.

What a storm! From black skies to blue ones in minutes, how did #brisbane cope? Details shortly #9NEWS 6pm @9NewsBrisbane pic.twitter.com/eTp3qCip1k — Ebony Cavallaro (@ebonycavallaro) November 12, 2016

In NSW and Queensland, the storms rushed well ahead of any drop in temperature. Sydney will have another hot but dry and breezy day on Sunday, but Monday should see a drop in temperature to about 23C. While in Brisbane, Sunday will bring more storms and run close to 35C.

Additional reporting by Rob McElwee.