Video courtesy of Nathaniel Chen via APTN
This incredible timelapse video shows a 'tsunami cloud' roll across the Sydney coastline.
The brewing storm was captured by local resident Nathaniel Chen from his office near Bondi Beach.
Local media said there were no reports of major damage but emergency services had received about 40 calls for assistance in coastal areas.
The Bureau of Meteorology warned of severe storms across Sydney, the Hunter region and the south and central coasts saying heavy rain and flash flooding may be in store.
However, Australia's ABC said a severe weather warning issued by emergency services had since been cancelled.