A tornado swept through Ulladulla on the NSW South Coast on Saturday, shocking residents, knocking down trees and damaging buildings, as intense rain, flash floods and winds lashed Sydney.

Greater Sydney and the CBD were struck by severe thunderstorms about 5pm on Saturday, with wind gusts reaching up to 72km/h in Sydney Harbour and up to 30 millimetres of rain falling in less than half an hour, triggering flash flooding in parts of the city.

The State Emergency Service rescued two people from cars in floodwaters in Moore Park and Darlinghurst.

In Edgecliff, vehicles were stuck in water as flash floods covered the street, while in Merrylands a tree was struck by lightning.

The tornado that ripped through Ulladulla tore roofs off homes and knocked down trees. The Bureau of Meteorology said the region recorded wind gusts of up to 98km/h.

Ulladulla mother Wishaya La Spina was in her car with her baby when she saw the tornado hit about 1pm.

“It was already storming, but nothing too severe. Then the wind just started to pick up and the next minute we spotted that little tornado,” she said.

She whipped her phone out to film, feeling helpless and unsure if she should stay in the car or flee.

“It was pretty scary,” said La Spina, whose baby was crying. “I was trying to protect him because you never know when a tree could come falling,” she said.

The Bureau of Meteorology issued a severe thunderstorm and damaging wind gusts warning for central and south-eastern parts of the state, including Sydney, Wollongong, Katoomba, Penrith, Parramatta and Bowral.

The SES recorded more than 230 calls for assistance across the state, most of which were located in Ulladulla.

Get to the heart of what’s happening with climate change and the environment. Sign up for our fortnightly Environment newsletter.