Sydney Weather: Boy, 14, SES worker die amid 'once in a century' storm

A 14-year-old boy, an SES volunteer and a driver have died following an historic storm swept through Sydney and coastal NSW.

The boy died in a car accident on Sydney’s North Shore yesterday, amid what has been described as a "once in a century" storm.

Police have confirmed the teen, who has not been named, was the passenger in the crash in Thornleigh, which involved two vehicles.

An NSW SES volunteer died after collapsing while on duty.

Commissioner Mark Smethurst and the NSW SES family sent “heartfelt condolences” in a statement to media.

A report will be sent to the coroner.

In South Wentworthville, emergency services were unable to revive a man after his car hit a pole just after 7pm.

Several roads were closed around the area and police called for anyone who may have seen the crash or have dashcam footage to come forward.

A male passenger was uninjured in the crash.

A police officer’s leg was also broken by a falling tree as the city copped the most rain dumped in a single day in the past 34 years.

A deluge of more than 100mm hit in just two hours this morning, causing flash flooding, power outages, and chaos on roads, public transport and at Sydney airport and across coastal NSW. It caused about 150 flights, mostly domestic, to be delayed or cancelled.

Some roads remain closed and many trains are cancelled or delayed and forecasters warned travellers to take care.

“There will be still periods of heavy rain hanging around. We probably won’t see easing conditions until this evening,” said Weatherzone’s Kim Westcott.

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Trains on the T1 North Shore line between Gordon and Hornsby are cancelled due to a tree falling on wire between Pymble and Turramurra. Replacement buses are planned

Ausgrid emergency crews are still working to restore power to 1,500 customers across Sydney, the Central Coast and the Hunter.

The main impacted areas include parts of Sydney CBD, Galston, Engadine, Milsons Point, Mosman, Sefton, Bankstown, Castle Cove, Roseville and Wahroonga.

More than 8,000 customers were without power this morning, and the company has responded to more than 120 hazards including trees and powerlines down.

Torrential rain also flooded two underground substations in the Sydney CBD.

Falling trees have also closed one of five eastbound lanes of The Crescent in Rozelle; southbound lanes of the Wakerhurst Parkway in Narrabeen, 

In North Narrabeen Southbound lanes of Wakehurst Parkway are affected just past Elanora Road.

Oxford Falls Road is closed between Wakehurst Parkway and Avoona Road and Blue Gum Road is closed in both directions at Blue Gum Creek in Annangrove.

In Maralya, McClymonts Road is closed in both directions.

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Meanwhile, people are advised to extra travel time for trains on the Blue Mountains Line, South Coast Line and Southern Highlands Line.

Buses are replacing Parramatta River ferries between Parramatta and Sydney Olympic Park as the weir is overflowing.

The SES has received more than 1000 calls for help and volunteers have performed more than a dozen rescues, including 11 from cars under water.

Ann Farrell, State Manager for the Bureau of Meteorology NSW, said: “That’s the wettest rainfall we’ve had in a daily total since 1984 and according to our estimates – for that intensity and duration – that’s the sort of rainfall you’d expect to see once every 100 years for that particular place.”

The State's highest rainfall was in Porter's Creek, near Ulladulla, which had 152mm. Towns as far west as Tamworth have been battered by hailstones the size of cricket balls.

However, the sunshine will return by Friday, with temperatures of up to 23