Key Points

A severe storm system crossed the coast on Tuesday, triggering widespread emergency warnings in the state of New South Wales (NSW), and intensified overnight as trees were brought down and buildings damaged.

NSW Police said on Wednesday that a 55-year-old male has been hospitalised in a critical condition after a tree fell and crushed the driver's cabin of his semi-trailer truck in the town of Moss Vale, 105 km southwest of Sydney, at about 10:30 p.m. on Tuesday.

Officers attended the scene and extracted the unconscious man from the vehicle. He was treated at the scene for serious head and torso injuries before being taken to the hospital in a critical condition.

According to the NSW State Emergency Service (SES), about 200 properties in the state's South Coast region, 180 km south of Sydney, were flooded overnight after some regions received more than 200 millimetres of rainfall in a 24-hour period.

As of 8 a.m. local time on Wednesday, more than 35,000 homes and businesses in NSW were affected by blackouts.

Sydney Airport said it expects cancellations and delays to continue throughout Wednesday, and strong winds have also forced cancellations at Brisbane Airport in the northeastern state of Queensland.

Millions of residents of Sydney and the cities of Newcastle to the north and Wollongong to the south have been advised to avoid non-essential travel, and public transport services have been widely disrupted.

Debbie Platz, deputy commissioner of the NSW SES, told Nine Network television that many residents across the state have heeded warnings and prepared their homes, preventing further damage.

She said the southern flank of the storm impacting Wollongong and surrounding regions is now the authorities' area of greatest concern, Xinhua news agency reported.

The Bureau of Meteorology said in a severe weather warning that the low-pressure system is expected to move east back out to sea later on Wednesday.

- IANS