Australia is officially in the grip of a double weather whammy that could mean a dangerously hot and dry summer for much of the country.
The Bureau of Meteorology has formally declared an El Nino event in the Pacific Ocean, to Australia's east, and a positive Indian Ocean Dipole (IOD), to the west.
El Nino typically delivers above average heat and drier conditions, particularly in eastern Australia. And a positive IOD tends to drive lower than average rainfall for large swathes of the country.
"When these two things occur together, that tends to increase the severity of rainfall deficiencies, in particular for the south east of the continent, over spring," bureau manager of climate services Karl Braganza said on Tuesday.
He warned hot, dry conditions were expected to persist until the end of summer.
"In all likelihood, we can expect that this summer will be hotter than average and certainly hotter than the last three years.
"Those conditions are accompanied by an increase in fire danger and extreme heat risk ... It's really up to individuals and communities now to prepare for a summer of heat and fire hazards."
While conditions aren't as bad as they were leading into the catastrophic fires of Black Summer, the landscape is rapidly drying out.
"Leading into Black Summer in 2019 ... we had years of preceding drought. We do have a wetter landscape out there, (but) it is drying out more rapidly than has occurred in recent years," Dr Braganza said.
"We are already seeing extreme conditions in some parts of the continent.
"Today, we've had catastrophic fire conditions on the south coast of NSW, just to underscore that risk."
Dr Braganza warned Victoria and NSW, in particular, tended to dry out under a positive IOD influence in spring.
The declarations coincide with severe weather warnings for swathes of Australia's southeast, including very hot spring conditions, elevated fire dangers and strong winds fuelled by an approaching cold front.
Large parts of NSW and eastern Victoria are enduring maximum temperatures 10 to 15 degrees above the September average.
A heatwave warning is in place for the NSW south coast, and a catastrophic fire danger warning is also current for the far south coast.
Damaging winds, driven by a cold front, are compounding the danger.
The front has triggered severe weather warnings for parts of South Australia, Tasmania, Victoria and southern NSW, with the possibility of showers, storms, small hail and snow in some areas.
While that will bring welcome relief from the heat in Victoria and NSW, the front will drive the extreme heat further north into Queensland, with the effects most pronounced there on Thursday.
Fire dangers will also pick up across the state, particularly in the south, with the Channel Country expected to reach extreme fire dangers on Thursday and Friday.
