A tornado has left a trail of destruction in Sydney's south with record wind speeds up to 213km/h leaving several people with minor injuries, and destroying homes and businesses.
The damaging winds wreaked havoc through the suburb of Kurnell, leaving trucks overturned and forcing the multi-billion dollar desalination plant and Kurnell Public School to be evacuated.
Some 300 workers were cleared out of the Caltex refinery as a safety precaution while further north three floors of a Bondi Junction shopping centre had to be evacuated after a partial roof collapse.
About 500 calls for assistance have been made to the SES, the majority coming from Sydney's south and east.
Eleven flood rescues were performed around Bondi and Eastlakes, while homes in Kurnell are expected to be without power and sewerage until Thursday at the earliest.
"Our volunteers will be busy for quite a while," an SES spokesman told AAP.
Residents in Sydney's south affected by the storm have been evacuated to Cronulla Leagues Club.
A Bureau of Meteorology spokesman said it is "very rare to get a tornado inside Sydney, much less a strong tornado".
"That is the fastest speed that has been recorded in NSW history."
Kurnell local Melanie Bowman said tiles had come off her roof and powerlines were down.
"I can see the sky from our garage ... I can see lots of parts of roofs in the street," she said.
"It felt just like a cyclone with hail and high winds."
Sutherland Shire Mayor Carmelo Pesce said he had been in contact with the office of federal treasurer and local member Scott Morrison, and expects the minister to make an announcement on Thursday about the government's disaster response.
Following the roof collapse at Bondi Junction, waiter Michael Seeff said customers ran out before paying the bill.
"Water was coming down the sides of the walls and onto the floor," he told AAP.
Kurnell Public School also suffered damage, with a tree falling on a classroom and the roof blown off another.
No one was injured with staff and students shifted to a nearby high school, a Department of Education spokesman said.
Sydney airport has advised passengers to check flight details with their airlines after Qantas delayed several flights and cancelled others on Wednesday.
Police said storm-affected Kurnell residents could start returning to their homes on Wednesday afternoon.
