Flood releases at south-east Queensland’s biggest dam, Wivenhoe, have begun as the state braces for more severe thunderstorms after a 127mm overnight deluge.
Brisbane, Mackay and Townsville are preparing for heavy rain and flash flooding, with isolated downpours of up to 250mm forecast.
Water was released out of Wivenhoe Dam to run into the Brisbane River from about noon on Tuesday, according to Seqwater.
Releases from Somerset Dam – which flows into Wivenhoe – were ongoing, and could cause water levels to rise by more than half a metre by Thursday.
Meanwhile, ongoing heatwave conditions will extend from the tropics into central and parts of eastern Australia today, creating dangerous bushfire conditions, the Bureau of Meteorology has said, as south-east Queensland battles rain.
Western Sydney will reach the low 40s, with temperatures hitting a maximum of 38C in Parramatta, 40C in Liverpool and 42C in Penrith.
Temperatures along the coast will be “a touch milder”, said Angus Hines, senior meteorologist at the Bureau of Meteorology. Bondi will reach a maximum of 29C. Terrey Hills in northern Sydney will hit 33C.
As of 10.30am AEDT, there were 12 active bushfires burning across New South Wales on Tuesday, five of which were not contained, with particular concern around the Hunter Valley area.
On Tuesday, NSW rural fire commissioner Rob Rogers warned “elevated temperatures” across the state would continue, with a “danger period” when winds pick up before a cool change forecast for the afternoon.
In Melbourne, temperatures were set to reach a high of 24C after yesterday’s heatwave in the city. Tullamarine and Watsonia were forecast to see a maximum of 26C.
A southerly buster will push up the east coast, reaching the Illawarra, Sydney and Hunter districts on Tuesday afternoon and evening. This will see temperatures cool for NSW on Wednesday “but still several degrees above average for large parts of Queensland and the Northern Territory, with heatwave conditions continuing through these areas”, Hines said.
Damaging storms are also possible, with the southerly change moving up the NSW coast this afternoon, Hines said. It brings a risk of severe thunderstorms, damaging wind, large hail and heavy rainfall this afternoon to the central and southern ranges, as well as parts of the Illawarra.
Overnight, showers and storms pummelled the east coast of Queensland, with South East Queensland Water confirming more than a dozen dams spilled over on Tuesday. In the 12 hours up to 6.30am, Cedar Creek Road in Brisbane received 127mm of rain, with other areas around both Brisbane and Maryborough getting about 100mm.
There are more evening showers and storms on the way for the rain-soaked region, with widespread areas of rain expected south of Mackay, and a risk of severe thunderstorms that could lead to flash flooding between Yeppoon and Brisbane.
This comes after temperatures reached into the 40s across large parts of the eastern states on Monday – “which is more than 10C above average for December for most areas”, the Bom said. Temperatures were “as high as 15 to 20C above average for parts of Victoria and South Australia”.
“Crews will be working very hard. We’ve had helicopter winched-in crews yesterday in a number of fires. We’ll be doing that again this morning with large air tankers to try to get containment on these fires as quickly as we can.”
In Victoria, Fire Management had a “really busy night” battling major blazes across the state, the chief fire officer, Chris Hardman, told the ABC on Tuesday morning.
About 300 firefighters are still located at active blazes with “many days’ work ahead of them”, he said.
Fires burning at Creswick and Candook have been downgraded and no lives or houses were lost, Hardman said.
Australia’s land surface has warmed by 1.5C since 1910, according to the BoM, with the climate crisis making heatwaves longer and more intense and increasing the number of extremely hot days.
