A new study has shown how local dynamic fire behaviour can create violent pyro-convection.On 22 November 2006, there were a number of bushfires burning in the Sydney basin. Two of these, in the Grose Valley and near Mt Coricudgy in Wollemi National Park, developed sets of blow-up fire events, which made the fires develop violent pyro-convection. The events were observed by radar, satellites and fire service linescans. Two peer-reviewed science papers have recently been published on the events of that day.

The first used the fact that this was the closest that NASA’s A-Train satellite flotilla had come to passing directly over a pyrocumulonimbus cloud (pyroCb) (above the Wollemi Fire). The unique datasets collected have expanded our knowledge of these dangerous events, and how they can impact on upper layers of the atmosphere. This is an illuminating case study of what can be learnt about a fire by a global scientific collaboration that includes meteorologists, atmospheric physicists and bushfire scientists.

The second paper explored in detail how atypical fire dynamics produced pulses of convective activity. For the first time, we showed exactly what is needed on the fire ground for explosive fire escalation to occur. We identified the effects of a precedent foehn wind event in allowing early drying of fuels, and of the vorticity-driven lateral spread that results from fire channelling.

This case study also shows that satellite and radar data contain much more information about fire dynamics than most users realise.

In total this work shows for the first time how all parts of a violent pyro-convective event link together. This can improve our skill in anticipating future events.