Slow-moving storm likely to make landfall on Friday or early Saturday, but winds already trigger power disruptions.
Tropical Cyclone Alfred has begun to lash Australia’s eastern coast, bringing large amounts of rain and record-breaking waves to a heavily populated region rarely hit by such storms and prompting evacuation orders in some areas.
Schools have been closed and public transport suspended as the region braces for the first cyclone in eastern Australia since 1974.
Alfred was 250km (155 miles) east of Brisbane on Thursday afternoon, but government forecasts warned its “erratic” crawl towards the mainland was growing difficult to predict.
Alfred was initially forecast to strike land late on Thursday. But the slow-moving storm – churning towards the coast at just 7 kilometres per hour (4 miles per hour) – was now more likely to make landfall late on Friday or early on Saturday.
The cyclone has already caused some damage with the power company Essential Energy reporting about 10,000 homes and businesses in the northern part of the state of New South Wales (NSW) have lost power after strong winds knocked down trees and damaged power lines on Thursday afternoon.
The NSW State Emergency Service has also issued evacuation orders for parts of the state due to possible flooding by 9pm (11:00 GMT) on Thursday.
More than four million people are in the firing line of the storm along a 400km (250-mile) stretch of coast expected to see the worst of the storm.
“We’re already seeing gales developing on the coastal fringe,” Bureau of Meteorology forecaster Sarah Scully told the AFP news agency.
“There have been very large waves and powerful swells. That’s generated by Alfred lingering in the Coral Sea and creating a whole lot of wave energy.”
A 12.4-metre (40ft) wave was recorded on the Gold Coast south of Brisbane, the largest swell ever picked up by that monitoring station.
Daring surfers paddled out to catch the supercharged waves, ignoring the threat of US$10,000 fines for “reckless behaviour”.
“I am just staggered that people would be so stupid. It is a huge act of stupidity,” acting Gold Coast Mayor Donna Gates said.
Alfred is expected to make landfall near Australia’s third largest city, Brisbane, the weather bureau said.
“There’s a lot of people in harm’s way here. We’re talking about something like four and a half million Australians,” federal Treasurer Jim Chalmers said.
While cyclones are common in the tropical waters lapping Australia’s northern coast, it is rare for them to form in cooler waters farther south.
Researchers have repeatedly warned that climate change amplifies the risk of natural disasters such as bushfires, floods and cyclones.
