What can be learned from the meteorological conditions and extreme fire behaviour at the 2019 Currowan fire in New South Wales and 2021 Wooroloo fire in Western Australia?
This question was at the core of the Centre’s March Hazardous Webinar, where attendees heard from fire and meteorology experts about the Fire case studies project and perspectives from the end-users who use the project outcomes.
The Webinar, hosted by Centre’s Node Research Manager Nicola Moore, included Fire case studies lead researcher and fire weather researcher in the High Impact Weather team of the Bureau of Meteorology’s Research group, Dr Mika Peace along with project end-users, New South Wales Rural Fire Service Manager of Predictive Services in the Community Resilience unit Chief Superintendent Laurence McCoy and Western Australia Department of Fire and Emergency Services Senior Environmental Officer Agnes Kristina.
Dr Peace’s defined case studies and why they are important to those working in the emergency management and natural hazards research sector in her presentation.
“Meteorological case studies are a detailed examination of a weather event. They tend to take a narrative form, and they document the features of extraordinary weather events to examine the causes and the impacts and importantly to present a scientifically plausible explanation for why events occurred,” Dr Peace said.
“The current Natural Hazards Research Australia Project has really been about developing a framework for more rapid turnaround of case studies using, in particular, the high-resolution coupled fire atmosphere simulations with ACCESS Fire and also a range of operational observational data particularly the radar data and the satellite data,” she said.
“The objective of the project has really been to do case studies cheaper and faster, using the two examples as a template”.
She said case studies are an evidence-based investigation and the core aim is to identify and then clearly document the physical processes that were responsible for extreme weather.
In her presentation, Dr Peace showed images of an ACCESS Fire simulation depicting half-hourly fire isochrones of the Currowan Fire boundary on a map.
In Mr McCoy’s presentation, he discussed why case studies are important as an end-user – in both a state-wide New South Wales context and beyond – and provided an overview of the Currowan–Lake Conjola Fire in 2019.
He said that with climate change, we are experiencing an increase in severity of weather.
“This year in New South Wales and Western NSW – we saw one of the hottest periods on record,” Mr McCoy said.
“It’s this increasing severity of weather that’s a key driver for the increase we have, or we are seeing, in extreme fire behaviour,” he said.
Mr McCoy said in 2019–20, there was a 50 per cent jump in the number of recorded fire-generated thunderstorm events – from 60 to 89 – and devastating, rare and unusual extreme fire behaviour in New South Wales, including fire generated vortices such as those that occurred at Green Valley.
“The Bureau, as we know, is a respected science-based organisation, and they’ve got a unique capacity to help us understand these events and to learn from them,” he said.
Mr McCoy said that case studies prepared by the Bureau of Meteorology are “so important” for New South Wales and are used to support legal and coronial investigations; inform operational, executive, or ministerial briefings; guide community information and public messaging; and to investigate, record, and learn from unusual events.
Following this, Agnes Kristina explained the conditions and extent of the 2021 Wooroloo Bushfire in Western Australia.
Ms Kristina said that the fire was first reported at 12:02PM on Monday 1 February, and by mid-afternoon, there were 500 firefighters, 95 vehicles and fixed-wing water bombers involved in the firefighting effort.
“Definitely, from this case, we understand that the 2021 Wooroloo bushfire was driven by extreme conditions, which is typical in Western Australian Summer, but made worse by the extreme drought,” Ms Kristina said.
“Mika’s studies, data, and science confirmed that what we observed during the incident was wind-driven during the day and night,” she said.
Ms Kristina explained that this data, science, and observations from the day could then be combined with ACCESS Modelling to assist in determining which observation locations most accurately represent the fire weather conditions.
Watch the Webinar replay below.