Up to 660,000 homes could be damaged if a category two cyclone makes landfall in south-east Queensland, government modelling suggests.
The region and northern NSW have been warned to prepare for the worst – as Tropical Cyclone Alfred approaches about 430km off Australia’s east coast.
The cyclone was set to develop into a category two system overnight and could be the first cyclone to batter both states in decades, with experts predicting it will cross the coast by Thursday.
It’s expected to head towards Brisbane on Tuesday, and re-intensify into a category two system before making landfall between Brisbane and Noosa overnight Thursday or early Friday, bringing destructive winds of up to 120km/h, heavy rainfall and hazardous surf conditions.
Four million Queenslanders have already been warned that they could be without power for at least three days once Alfred makes landfall.
A Severe Wind Hazard Assessment conducted by government agency Geoscience Australia in 2022 revealed the extent to which a category two cyclone could ravage the densely populated region.
The report detailed a series of potential scenarios, one of which is similar to that which faces south-east Queensland this week.
The scenario outlines the result of a category two cyclone crossing the coast near Bribie Island, barrelling through the Brisbane CBD and leaving the mainland via the Gold Coast.
A resurfaced Geoscience Australia report outlines the potential destruction of a category two cyclone in Queensland’s densely populated south-east
Strong marine winds and rough swells have already smashed Queensland and northern NSW coast ahead of Cyclone Alfred making landfall. Pictured is the Gold Coast on Monday
Such a cyclone, according to the report, could wreak havoc on up to 660,000 homes with the damage ranging from minor to extensive.
‘The main impacts are concentrated at the southern end of Moreton Bay around Macleay and Russell Islands, and into the northern suburbs of Gold Coast City Council near Ormeau and Pimpana, with widespread areas of moderate damage,’ the report stated.
‘Parts of Macleay and Russell Islands sustain extensive damage from winds, but would also likely sustain substantial damage from storm tide in this scenario.’
In the case of the report’s example cyclone occurring, 23,000 homes in the Redlands region would cop moderate to extensive damage.
About 250,000 homes in Brisbane would also be damaged.
Only 2,800 of which, however, would experience moderate or extensive damage.
On the Gold Coast, 155,000 homes would be impacted, though less than 7,600 would be moderately or extensively damaged.
The scale of impact in each modelled scenario in the report would depend on the size and intensity of the tropical cyclone.
So too would it depend on the landscape upon which buildings are located and where the cyclone made landfall.
The resurfaced report suggested more than 660,000 homes could be at risk if Cyclone Alfred turns out anything like Geoscience Australia’s simulations
Four million Queenslanders could be without power for up to three days once Alfred makes landfall. Pictured is the Gold Coast on Monday
The Redland region of SEQ would see the most extensive damage in the case of a category two cyclone arriving to the area, the report’s modelling suggested
‘Where there are heavily urbanised areas, there is typically lower damage, due to the lower incident wind speeds likely to be experienced,’ the report stated.
‘That contrasts with areas in the Gold Coast and Sunshine Coast hinterland, where local accelerations over the steep topography will amplify the level of damage to houses in those areas.
‘A Tropical Cyclone passing over the northern council areas will result in overall lower damage, but that may still be overwhelming for that community.’
Authorities in northern NSW and south-east Queensland have warned residents from K’gari/Fraser Island to as far south as Grafton in northern NSW to be prepare.
The cyclone could bring gusts of up to 125km/h, damaging tides and swells, and heavy rainfall.
Experts fear these factors could contribute to life-threatening coastal erosion and flash flooding.
Alfred was 550km east of Brisbane as of late Monday night.
The region’s island communities, including Bribie, Stradbroke, Moreton have been urged to decide by Tuesday morning whether to stay or bunker down
‘We are putting all the preparations in place and we are asking all Queenslanders to do the same,’ Queensland Premier David Crisafulli said.
‘We are dealing with a very heavily populated part of the state … that hasn’t seen a cyclone for many years, in fact many decades.’
Residents should prepare for at least three days without power.
‘Energex has been preparing for Cyclone Alfred since last week and the community can rest assured that we’re ready to respond to anything Mother Nature throws at us,’ Premier Crisafulli added.
The latest Bureau of Meteorology alerts warned the cyclone could cause major flooding in coastal rivers along the 450km stretch between Queensland border and Port Macquarie on the NSW mid north coast, along with hazardous surf conditions.
A flood watch is also on south-east Queensland with a marine wind warning for gale force winds.
The agency has modelled thousands of possible cyclone outcomes in Australia; above is a potential path, including a wind field impact graphic (green), for a category two cyclone making landfall near Bribie Island
Council workers helped residents in Burleigh collect sandbags on the Gold Coast on Monday
‘Many coastal impacts with damaging (erosion) and hazardous (activities) surf warnings current,’ the bureau said.
The Queensland SES has issued a three-step plan for those in potential impact zones.
‘The weather and its impacts can vary across the state and knowing your location will help you understand the hazards you may face. Get to know your local environment and research the potential impacts of severe weather,’ it says.
‘Make an emergency plan; Pack an emergency kit; Prepare your property.’
‘This plan should reflect specific needs of all family members and outline the steps to take should an emergency arise.’
‘Pack an emergency kit with essentials that can last you a minimum of three to seven days in case you lose power or do not have access to clean water.’
‘Storm proof your roof and keep your home and property in good condition by regularly checking your roof for repairs, keeping gutters clean as well as safely trimming trees and overhanging branches.’
‘Secure, weigh down or put away any loose items around the house, yard or balcony. Items such as potted plants, outdoor furniture, garbage bins, and trampolines can become dangerous missiles.’
‘Identify the strongest room in your home to shelter in during storms and cyclones. Usually this would be the smallest room in the house, with the least windows.’
