A time-lapse video shot by Sydney resident Nathaniel Chen shows a huge set of storm shelf clouds as they cover the city. Chen shot the video from his office around 1.30pm Sydney time on 6 November.
The video shows the storm approaching from the right-hand side across the bay, threatening the city with dark grey clouds.
Shelf clouds, also called wall clouds, are formed by a process known as entrainment, when an inflow of warm, moist air rises and converges, overpowering wet, rain-cooled air from the downdraft.
Another video, shot by Sydney resident Jack Crombie from his roof, shows the storm descending over the beachside suburb of Clovelly.
Sydney media said there were no reports of major damage from the storm, but emergency services had received about 40 calls for assistance in coastal areas.
Australia's ABC said a severe weather warning for Sydney issued by emergency services has been cancelled.