Awe-inspiring though it is, this is not a sight you want to see from your kitchen window.
This towering structure is known as a pyrocumulus cloud – a sure sign that a bushfire has morphed into a full firestorm, complete with its own devastating effects.
“These firestorms create their own weather with lightning, strong winds, and even tornadoes that spread fire in multiple directions,” explains Rachel Badlan from Australia’s UNSW Canberra. “These ingredients make them impossible for firefighters to put out.”
Badlan, colleagues from the university and members of the Australian Capital Territory Emergency Services have completed an extensive research project that found that the shape of a wildfire determines whether it will transform into a firestorm.
A blaze that spreads out across a long frontline, they discovered, is less likely to morph than one which stays in a concentrated area.
The findings will inform both land management strategies and the tactics used by fire services in tackling big fires.
“With firestorms commonly occurring in Australia — more than 50 since 2001 — and set to increase due to hotter and drier conditions, it’s vital that fire managers can determine which fires are likely to transition into a firestorm so that evacuation may occur as early as possible,” Badlan says.