Strong winds and heavy rain have downed trees, damaged properties and flooded roads as a complex weather system lashed Australia's east coast.
The coastal low-pressure system, described by meteorologists as a "bomb cyclone", brought wind gusts of more than 100km/h. Roughly one month's worth of rain fell over six hours in some regions.
The weather phenomenon forms quickly and causes air pressure to drop significantly within a short period of time.
Emergency crews had a busy workload overnight on Tuesday, pulling off seven flood rescues on the south coast of New South Wales, all caused by people driving into floodwaters.
About 200 properties in Burrill Lake on the NSW south coast were flooded overnight, while more than 200mm of rain smashed several towns, including Morton and Ulladulla.
The State Emergency Service fielded 745 calls on Wednesday morning alone as residents took stock of the overnight damage. Chief Superintendent Dallas Burnes expected a busy day ahead.
"It's going to be 36 hours now some of these trees and roofs (have been) exposed to strong winds and isolated gusts," he told ABC radio this morning.
"After a while, those trees in saturated ground fall over and those roofs give up the ghost and peel off."
A 55-year-old man was taken to hospital with serious head and torso injuries after a tree fell and crushed his truck in Moss Vale, in the southern highlands.
Police, paramedics and emergency crews freed the unconscious man from the driver's cabin of his truck at 10.30pm yesterday.
Communities stretching from Queensland's Lockyer Valley to Bega on NSW's south coast are still being warned to take care as severe weather driven by a "vigorous" coastal low lingers offshore.
The storm, called a cyclone bomb, was expected to track south today before turning back out into the Tasman Sea on Thursday.
Isolated totals up to 120mm remain possible but conditions were expected to ease later in the day.
There are 29 warnings current, with evacuation messages for communities on the Central Coast and south coast, including Sanctuary Point.
SES crews had responded to more than 2320 incidents by early today, as the low shifted southwards from Newcastle toward Sydney, the Illawarra and South Coast.
More than 37,000 homes and business were without power.
Residents were being warned to evacuate amid coastal erosion on the Central Coast. Dunleith Tourist Park manager Ryan Lloyd told AAP the beaches were heavily affected as wind gusts and swells intensified.
"It's pretty wild - pretty full on - a bit scary for the home-owners too," he said.
There were patches of blue in the sky but they were otherwise surrounded by dark clouds.
But the rain was less of a concern than the strong winds.
"We've already had plenty of tree branches down ... they're dropping limbs everywhere," Mr Lloyd said. "It's just battening down now, just wait for it to blow over - pardon the pun - then a massive clean-up for the next couple of days."
Sydney's Warragamba Dam was expected to spill in the coming days, however has not yet reached capacity after 56mm of rain in 24 hours.
The Bureau of Meteorology is predicting another low-pressure system to enter the storm's path later today.
"We see another low-pressure system, really dumb-belling around that first one, that will really intensify and reinforce some of those winds and rain across the south coast," senior meteorologist Jonathan How said.
The system extends about 5km into the sky, with two low-pressure systems interacting with one another in a phenomenon known to meteorologists as the Fujiwhara effect.
Several roads in the state's Illawara region south of Sydney have been closed due to flooding and fallen trees. Evacuation orders were issued due to coastal erosion in the Central Coast region, while dozens of warnings remain for wind damage and flash flooding.
Transport disruptions
Many flights have been cancelled from Sydney Airport for the second consecutive day.
Qantas Airways and Virgin Australia, the country's biggest airlines, have together cancelled at least 55 domestic flights in and out of Sydney on Wednesday, the airport's website showed. Some international flights have been delayed.
Sydney's train services have also been disrupted, with authorities urging people to avoid non-essential travel.
"Be really careful. It's really wild out there, if you can delay travel, please do so," Burnes told ABC News.
Conditions were expected to worsen through Wednesday before the system eases and move into the Tasman Sea, and then track toward New Zealand tomorrow.
New Zealand's National Institute of Water and Atmospheric Research said the low-pressure system could bring heavy rain and strong winds to the North Island and top of an already sodden South Island on Thursday and into the weekend.
- AAP and Reuters
