Temperatures are expected to soar across northern Australia over the coming days as a heatwave spreads across Western Australia, the Northern Territory and Queensland.
Weatherzone meteorologist Ben Domensino said hot air was building over the north-west of the continent and moving east, driving temperatures in some areas as high as 5C to 6C above average.
Temperatures in WA’s Marble Bar, in the Pilbara, exceeded 45C on Sunday and Monday, Domensino said. “That Sunday was the first 45C observation in Australia this season.”
Modelling suggested temperatures in northern WA could reach 47C by the coming weekend, he said.
“It won’t be quite as hot in the Northern Territory and Queensland, but there is still a severe to extreme heatwave forecast for northern areas of WA, the NT and Queensland over the next several days,” Domensino said. “You might see some inland areas of the Northern Territory reach 44C or 45C.”
Parts of western Queensland, such as Mount Isa, are forecast to reach 44C on Sunday.
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The Bureau of Meteorology forecasts that in parts of central and western Queensland, maximum temperatures will rise to the low to mid-40s, with overnight minimums potentially in the high 20s.
Pieter Claassen, a senior meteorologist at the bureau, said he expected “temperatures peaking in the mid- to high 30s on Thursday for [Queensland’s] south-east before a cooler change on Friday, dropping temperatures by about 10C”.
In the northern interior of the state, he said, temperatures would peak in the low to mid-40s on Friday.
Claassen said the heatwave was “less normal during a La Niña but these temperatures can certainly happen”.
“The temperatures we are forecasting are very warm but not unprecedented – some places could see their warmest December day in about three years.”
Domensino said the heatwave was developing because of a “monsoon break”. In the monsoon season, north-westerly winds arrive over northern Australia, which help to suppress temperatures.
“But at the moment, we’re in a monsoon break and that’s allowing that intensely hot air mass to build up over northern Australia,” he said.
Domensino said the 45C recorded in Marble Bar over the weekend was the latest in the season that mark had been broken since 1999.
“Because of the negative Indian Ocean dipole and La Niña, we actually haven’t seen the first 45C until a little bit later than usual,” Domensino said.
“With that negative Indian Ocean dipole there’s been more cloud cover, which has helped to suppress the temperatures over northern Australia.”
The BoM confirmed on Tuesday afternoon that the IOD had swung into a neutral phase, with the index showing neutral values for five consecutive weeks.
It also said a La Niña was ongoing in the Pacific Ocean, but modelling suggested a return to neutral in January or February. “The Bureau’s long-range forecasts continue to indicate above-median rainfall is likely for much of eastern Australia at least during early summer.”