The Bureau of Meteorology has declared two major climate drivers linked to hot, dry conditions are officially underway in Australia, prompting further warnings that extreme heatwaves will hit this summer.
After months of anticipation, the bureau has confirmed the world’s most consequential climate driver, the El Niño weather pattern, is active over the Pacific for the first time in eight years.
At a press conference on Tuesday afternoon, the bureau also announced the lesser known, but also significant, climate driver, known as a “positive” Indian Ocean Dipole (IOD), has also developed.
The onset of the two major climate events means the remaining months of 2023 in Australia are likely to be hot and dry, particularly in the eastern states.
Combined with the background warming of climate change, climate scientists have warned Australia could be in for a summer of severe heatwaves.
“When [an El Niño and positive Indian Ocean Dipole] occur together, that tends to increase the severity of rainfall deficiencies,” the bureau’s head of climate monitoring Karl Braganza said.
The announcement comes as parts of New South Wales are put on alert for “catastrophic” fire danger, as strong winds combine with unusually hot temperatures in the south-eastern parts of the state.
Eastern Pacific sea surface temperatures — one of the key indicators of El Niño — rose well above the El Niño threshold during autumn, prompting several international agencies, including the US weather authority and the World Meteorological Organization, to declare the event underway months ago.
El Niño influences the climate patterns of 60 per cent of the globe, with Australia particularly vulnerable to its impacts.
The major climate driver is characterised by a shift in warm waters and cloud from the western Pacific to the central Pacific, which leads to a reduction in rain over Australia and increased temperatures.
This means it is often associated with drought, heatwaves and bushfires.
The dry influence is particularly strong for Queensland and New South Wales.
Both El Niño and the Indian Ocean Dipole are known to increase the bushfire risk in Australia, according to the bureau.
Adding to the picture this year is grass growth thanks to back-to-back years of heavy rain, according to Australasian Fire Authorities Council (AFAC) chief executive Rob Webb.
“But regardless of La Niña or El Niño, Australian communities in those summer months must be aware of dangerous weather conditions …and preparation is the key.”
AFAC will release its summer bushfire outlook at the end of November.
(ABC)
