When former NSW Rural Fire Service district manager Superintendent Patrick Westwood described the "freakish" weather and winds of fires he attended, he said "veteran firefighters don't believe what they saw".
The winds were strong enough to fatally flip an 8-tonne fire truck, the same winds he and his team battled during the Green Valley bushfire in 2019.
So in response, scientists are now working to get ahead of deadly fire weather.
They simulate their own firestorms on a Canberra-based supercomputer, one the biggest in the Southern Hemisphere, to better understand what drives the increasingly erratic weather facing fire crews.
Bureau of Meteorology senior research scientist Dr Mika Peace and her team have picked five fires to study from the 2019-20 Black Summer event:
Badja Forest, New South Wales
Green Valley Talmalmo/Corryong, NSW/Victoria
Kangaroo Island, South Australia
Yanchep, Western Australia
These fires were put forward to Dr Peace's team due to the complexities in suppressing and containing them.
It takes an entire day to simulate just one day of these fires with the Australian Community Climate and Earth System Simulator (ACCESS) fire model on the National Computing Infrastructure (NCI) supercomputer, but the research is paying off.
"The Black Summer fires really provided the motivation to look at these fires in more detail because some of the traditional methods of surface-based fire prediction simply weren't working," Dr Peace said.
"[They] weren't giving the right results that matched the observations in Black Summer.
"The fires [were] releasing so much energy this was changing the surrounding atmosphere and then having an impact on how the fires progressed."
Predicting a firestorm
The factors behind each fire are complex and there is no single predictive formula.
The research shows that drought and heatwave conditions experienced in the lead-up to and during all five fires were a key factor in priming the landscape for extreme fire behaviour.
But local weather conditions, including sea breezes and hot overnight conditions, were also important when combined with the very dry vegetation.
"One of the interesting things is we looked at five different fires, and in each of those five fires the processes were different, so there's not a one-solution-fits-all scenario in term of predicting the fire's behaviour," Dr Peace said.
"The fires were interacting with the atmosphere in different ways in each fire.
"What we are seeing is some of the local interactions between the fire and the atmosphere really do have a big impact on how the fire spreads and how the fire behaves.
"Particularly [of interest is] when we are looking at things like sea breezes interacting with the fire front, winds mixing down from above the surface, and these extreme fire generated winds that happened from behind the fire front."
Scientists are now working to break down the results and roll out their knowledge to those on the ground.
"We have been talking with these fire agencies around the country and we are developing training material to help ? look for the ingredients which are favourable in providing the right conditions for extreme fire behaviour to occur," Dr Peace said.
"We can look out for these kinds of scenarios in future and respond appropriately."
Helping fire fighters in real time
The research started in 2010, but Black Summer pressed the need to better understanding the "freak" fire weather firefighters were reporting.
The studies will also focus on fire-generated weather seeds, such as the fire tornadoes that developed during Black Summer, and working out models to better identify where they might develop in future.
Eventually, the fire modelling could be run simultaneously with Australian fires to help firefighters get on the front foot, particularly as climate change and heatwaves are predicted to fan larger blazes in the future.
"It certainly is going to be the way of the future at some point that we have some kind of coupled simulation capacities running in real time," Dr Peace said.
"The question at the moment is what it looks like and how much computing power we have and need to run these computing models on-demand."
The research was a partnership between the Bushfire and Natural Hazards Cooperative Research Centre and the Bureau of Meteorology, run in collaboration with fire and land management agencies in each state.
Its Black Summer research program is investigating key issues from the 2019-20 bushfire season.
© ABC 2021
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