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Cyclone Alfred: What we know about rare storm near Australian coast

Millions of residents have been warned about the risk of life-threatening flooding and dangerous gusts of wind. But what is a cyclone, what kind of threat does it pose, and what is being done about it?

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Tropical Cyclone Alfred was expected to become the first cyclone to cross the east Australian coast near the Queensland state capital since 1974.

Residents were told to brace themselves for the "significant risks" Cyclone Alfred poses, but the weather event was weakened to a tropical low tropical weather system on Saturday morning.

Despite the weakening, Australian Prime Minister Anthony Albanese warned people to "remain alert", adding that heavy rain, strong winds and flooding will continue to pound southeast Queensland and northern New South Wales.

The impact is already being felt, with tens of thousands of homes without power and heavy flooding in some regions, which has seen a man get swept off a bridge in New South Wales.

But what is a cyclone, what kind of threat does it pose, and what is being done about it?

What is a cyclone?

A tropical cyclone is a rapidly rotating storm that begins over tropical oceans. It can vary in speed, size, and intensity.

The term cyclone is used once a storm reaches maximum sustained winds of 74mph or higher.

It differs to a tropical low, which is defined as bringing sustained winds of less than 39mph.

Satellite image shows three cyclones, including Alfred on the left. Pic: AP
Image: Satellite image shows three cyclones, including Alfred on the left. Pic: AP

A cyclone is the same phenomenon as a typhoon or hurricane, but they are referred to differently depending on where they happen.

The term cyclone is used when the storms occur in the South Pacific and Indian Ocean. They are referred to as typhoons when they appear in the Northwest Pacific and as a hurricane in the North Atlantic, central North Pacific and eastern North Pacific.

Read more: What is the difference between a cyclone, typhoon and hurricane?

What kind of threat did Cyclone Alfred pose?

Alfred was 150 miles east of Brisbane and moving west on Thursday, with sustained winds near the centre of 59mph and gusts of 81mph, according to meteorologists.

Before it was downgraded, it was forecast to cross the Queensland state coast early on Saturday, somewhere between the Sunshine Coast region and the city of Gold Coast to the south.

The cyclone came to a near-standstill off the Brisbane coast for several hours on the first day of the weekend, but it is still forecast to track west across the Australian mainland in the coming days, bringing heavy rain, Matt Collopy, manager at Australia's Bureau of Meteorology, said.

The Australian Bureau of Meteorology Tropical Cyclone Warning Centre's forecast track map
Image: The Australian Bureau of Meteorology Tropical Cyclone Warning Centre's forecast track map

The forecaster had predicted that the storm would weaken as it approached Brisbane, saying "destructive winds" were unlikely, but "damaging wind gusts" of up to 120kph [75 mph] were still expected.

Australian meteorologist Tony Auden told Sky News that the cyclone had the potential to be on a scale the country hasn't seen in a "generation" or "a lifetime".

He said the last comparable cyclone to hit the area was in 1954.

"The worry here is back then, the population in the firing line was 36,000 people - this time, it's 4.5 million people in that firing line, with some very nasty weather on the way in the next few days," Mr Auden explained.

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'Cyclone likely to be on a scale not seen in our lifetime'

What is happening now?

Heavy rain and flooding remain the main concern for people on the east coast.

A number of flood warnings are in place, with the Bureau of Meteorology warning that "rivers are rising rapidly" and flash floods also pose a "huge risk".

Police confirmed that a 61-year-old man who disappeared in a flooded river near the New South Wales town of Dorrigo had died after his body was recovered on Saturday.

Modelling shows up to 20,000 homes in Brisbane, a city largely built on a river floodplain, could experience some level of flooding.

Worker repairs power lines damaged by fallen tree in Northern New South Wales. Pic: Reuters
Image: Workers repair power lines damaged by fallen trees in New South Wales. Pic: Reuters

The coast near the border has been battered for days by abnormally high tides and seas. A 40ft wave recorded off a popular Gold Coast beach on Wednesday night was a record for the area, officials said.

Fallen trees have already damaged power lines, homes and cars, while the region's renowned beaches have become steep sandy cliffs after days of relentless erosion.

"We've never seen such weather at the coast," Pedro Machado, a local who has lived on the Gold Coast for eight years, told The Associated Press.

People watch as huge swells hit the beaches on the Gold Coast, Australia..
Pic: AAP/AP
Image: People watch as huge swells hit the beaches on the Gold Coast. Pic: AAP/AP

Brisbane streets have been largely empty of traffic for the past few days, with supermarket shelves stripped bare of basics including bread, milk, bottled water and batteries.

In Queensland, a woman sustained minor injuries when an apartment building lost its roof, officials said. She was one of 21 people who were evacuated from the building.

Debris lies at a damaged house by a fallen gum tree ahead of Tropical Cyclone Alfred's landfall, at Mudgeeraba on the Gold Coast, Australia.
Pic: AAP/Reuters
Image: A house damaged house by a fallen gum tree on the Gold Coast. Pic: AAP/Reuters
Fallen trees are pictured ahead of Tropical Cyclone Alfred's landfall at Pottsville Beach, Northern New South Wales, Australia.
Pic: AAP/Reuters
Image: Fallen trees are pictured at Pottsville Beach, Northern New South Wales. Pic: AAP/Reuters

Police added that two people narrowly escaped a large tree falling on their home in the Currumbin Valley in Queensland on Thursday night. They were lying only inches from where the tree came to rest in their bedroom, they said, adding both suffered minor injuries.

More than 330,000 homes and businesses lost power on both sides of the border, a large proportion of them on the Gold Coast, which recorded the strongest gusts of 107kph (66 mph) on Friday night.

Queensland Premier David Crisafulli said the outage is the "largest ever loss of power from a natural disaster" in the region's history.

He said authorities and emergency services are "throwing everything" at restoring power to those affected and clearing roads that have been blocked by fallen debris.

Boys play in sea-foam at Coolangatta ahead of Tropical Cyclone Alfred's landfall, on the Gold Coast, Australia.
Pic: AAP/Reuters
Image: Boys play in sea-foam at Coolangatta on the Gold Coast. Pic: AAP/Reuters

What is being done about the cyclone?

Many of the areas likely to be badly affected have already been evacuated, after authorities urged residents to clear the regions by Thursday morning if possible.

A number of flights in the affected regions have been cancelled, and operators have warned more are likely over the coming days.

Boys shelter from waves behind a break-wall at Coolangatta ahead of Tropical Cyclone Alfred's landfall, on the Gold Coast, Australia,.
Pic: AAP/Reuters
Image: Boys shelter from waves behind a break-wall at Coolangatta. Pic: AAP/Reuters

Hospitals are not carrying out non-urgent surgeries and public transport is not running until the danger passes, Brisbane officials said earlier in the week.

Queensland Premier David Crisafulli said: "This is a very rare event for southeast Queensland, I acknowledge that, but I'm asking Queenslanders to take it seriously and I want you to know that we are taking it seriously.

"If you are in a storm tide zone or you're in an area where you know there is riverine flooding, you really need to consider and think about your evacuation plan now," he added.

Residents collecting sandbags at a depot on Bribie Island in Queensland. Pic: AP
Image: Residents collecting sandbags at a depot on Bribie Island in Queensland. Pic: AP
Giant sandbags being laid out by an excavator in preparation for Alfred. Pic: AP
Image: Giant sandbags being laid out by an excavator in preparation for Alfred. Pic: AP

On Monday, an adventurer had to be rescued by a warship in the Coral Sea around 460 miles east of the Queensland coast after getting caught up in the cyclone's 50mph winds.

Lithuanian rower Aurimas Mockus, 44, was in the final stages of his 7,500-mile voyage across the Pacific Ocean from the US to Australia, which he started in an enclosed boat in October, when he became stranded for three days before being rescued.

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Watch moment stranded ocean rower is rescued

How long is severe weather meant to last?

The Bureau of Meteorology Australia said the peak of flooding is expected to occur overnight on Saturday into early Sunday.

The national forecaster said areas experiencing the heaviest rainfall could see up to 200-300mm of rain in the next 24 hours, with isolated wind gusts of up to 90kph (55mph).

A severe weather warning is in place for "heavy to locally intense rainfall" and "damaging winds", covering areas to the south of Gympie in Queensland all the way down to Nambucca Heads in New South Wales.

The forecaster said a "gradual easing" of the intense rainfall should be seen by Monday night, but this depends on how the system moves across the country.

More than 1,000 schools in southeast Queensland and 250 in northern New South Wales were closed on Thursday, while public transport across Brisbane has been suspended.

Read more:
Vast 'megaberg' the size of Gloucestershire runs aground
How do cyclones work - and why are storms named?

A brief history of cyclones

Cyclones are common in Queensland's tropical north but are rare in the state's temperate and densely populated southeast corner that borders New South Wales.

The last cyclone to hit southeast Queensland and northern New South Wales was Cyclone Zoe in March 1974.

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It crossed the coast at the southern end of the Gold Coast on the New South Wales border and caused extensive flooding.

The last time a cyclone threatened Brisbane was in 1990, but the system tracked south just before reaching the city.

More than 1,900 disasters have been attributed to tropical cyclones worldwide since 1970, according to the World Meteorological Organisation, resulting in more than 790,000 deaths and $ 1.4trn worth of damages.