Sydney has again been battered by a summer storm with parts of the city pelted with hail.
The Bureau of Meteorology warned of severe thunderstorms and heavy rainfall that could lead to flash flooding, destructive winds and "giant hailstones" on the east coast, stretching from Lismore in the north to Moruya Heads on the south coast.
Residents of Oran Park and Harrington Park in Sydney's west seemed to cop the brunt of the hail, with residents reporting hailstones the size of tennis balls and golf balls.
Suburbs across Sydney looked as though they had been blanketed by snow.
Photos have begun circulating on social media of damage to cars parked outside or driving when the storm hit, with reports of broken sunroofs and windows.
One Sydney resident was in a taxi when massive hail smashed through the back window.
Other city residents are posting photos of huge dents on bonnets and roofs.
The storm warning also stretched west to the central tablelands and central western slopes and plains with Dubbo experiencing small but significant hail.
The Bureau said 8-centimetre hail was reported in Casula in Sydney's south-west, Berowra and Berowra on the upper north shore.
Paddington, Cabramatta and Padstow also had reports of large hail.
Winds of up to 140 kph were recorded near Narrabri and Wee Waa in the north west slopes, while Murrurundi and Scone in the Upper Hunter recorded 114 kph and 111 kph, respectively.
Wind gusts reached 90 kph at Richmond Airport in Sydney's west.
The Bureau said "very dangerous thunderstorms" were detected on the weather radar near Gosford and Mona Vale, moving east to north-east.
The central coast was also hit by the severe thunderstorms.
Other storm cells were forecast to affect Sutherland, Campbelltown and Bowral as well as Wollongong, Kiama and Port Kembla.
The State Emergency Service said it had responded to 421 jobs since midday.
A spokesperson said the worst-hit areas were Liverpool and Berowra, with "almost every second home" in Berowra needing assistance.
Prestons, the Hills District and Hornsby were also badly affected, with most callers needing help with leaking roofs and hail damage.
The Insurance Council of Australia has declared the storm an "insurance catastrophe" with damages estimated to be worth millions of dollars.
Air Services Australia said that during the height of the storms planes were not landing at Sydney Airport.
Sydney Airport said the bad weather had caused delays of up to 90 minutes at the domestic terminal and three hours at the international terminal.
Sixty-two flights had been cancelled and seven had been diverted.
The Transport Management Centre said trains were running again between Bankstown and Sydenham on the T3 Bankstown Line, after they were earlier forced to stop due to urgent power supply repairs caused by severe weather.
Buses are still replacing trains between Campbelltown and Macarthur on the T8 Airport and South Line due to urgent track equipment repairs at Macarthur.
Buses are also replacing trains on the T7 Olympic Park line between Lidcombe and Olympic Park due to flooding, and on the Blue Mountains line between Mount Victoria and Lithgow after storms damaged signal equipment.
A spokesperson advised commuters to allow extra time for travel.
Ausgrid said 12,800 customers were without power, with the Central Coast areas of Avoca, Wamberal and Gosford worst affected. Customers at Arncliffe, Bexley, Rockdale, Galston, Hornsby Heights and Mt Colah were also without power.
Endeavor Energy said they were working to reinstate power to more than 25,500 across western Sydney, Blue Mountains, Lithgow and the Hawkesbury.
