A rare tornado hit Sydney on Wednesday with destructive winds above 200 km an hour (125 mph) and cricket ball-sized hail, bringing down trees and power lines, tearing off roofs, overturning vehicles and causing flash flooding.
The Australian Bureau of Meteorology (BOM) issued the rare tornado warning around midday as the dangerous storm swept up the coast from Sydney's south, forcing some international and domestic flights to be diverted to other cities.
"There is obvious evidence that we have had a tornado go through Cronulla [a southern Sydney suburb] today," BOM meteorologist Alan Sharp told Sydney media.
There were no reports of major damage and only a handful of people were reported injured as the storm passed over Australia's largest city.
Social media was swamped by pictures of the huge, dark storm as it engulfed the harbour city, plunging a 25 degree Celsius (77 Fahrenheit) summer's day into darkness.
Wind gusts as high as 213 kmh (132 mph) were recorded in the beachside Kurnell neighbourhood near Sydney's airport, said the weather bureau.
A spokeswoman for Sydney International Airport said the airport had not closed but a handful of flights were diverted to different airports.
The large hail damaged cars, smashed windows, and tore shop awnings and yacht sails to shreds.
Some 6,000 homes were reportedly without power south of the city and rescue services received more than 200 calls for help in the city, according to media reports.
"The tornado risk has now subsided but there is a very good chance of more thunderstorm activity for the rest of today," said James Taylor, senior meteorologist with the Bureau of Meteorology extreme weather desk.
"It is not out of the question there could be very localised tornadic activity but that will be something we will monitoring very closely for the rest of the day," he said.
Australia is experiencing an El Niño weather pattern, a phenomenon associated with extreme droughts, storms and floods, which is expected to become one of the strongest on record, the UN weather agency said earlier this year.