Introduction to the Australian Fire Danger Rating System†

Background Climate projections signal longer fire seasons and an increase in the number of dangerous fire weather days for much of the world including Australia. Aims Here we argue that heatwaves, dynamic fire–atmosphere interactions and increased fuel availability caused by drought will amplify potential fire behaviour well beyond projections based on calculations of afternoon forest fire danger derived from climate models. Methods We review meteorological dynamics contributing to enhanced fire behaviour during heatwaves, drawing on examples of dynamical processes driving fire behaviour during the Australian Black Summer bushfires of 2019–20. Results Key dynamical processes identified include: nocturnal low-level jets, deep, unstable planetary boundary layers and fire–atmosphere coupling. Conclusions The future scenario we contend is long windows of multi-day fire events where overnight suppression is less effective and fire perimeters will expand continuously and aggressively over multiple days and nights. Implications Greater overnight fire activity and multi-day events present strategic and tactical challenges for fire management agencies including having to expand resourcing for overnight work, manage personnel fatigue and revise training to identify conditions conducive to unusually active fire behaviour overnight. Effective messaging will be critical to minimise accidental fire ignition during heatwaves and to alert the community to the changing fire environment

Section: Normal Diurnal Cycle Of Fire Activity and Vapour Pressure De...mentioning

confidence: 99%

Future fire events are likely to be worse than climate projections indicate – these are some of the reasons why

Peace,

McCaw

2024

“…Article 1 (Hollis et al 2024b) introduces the AFDRS and provides a short history of fire danger in Australia together with requirements to make advancements;…”

Section: Introductionmentioning

confidence: 99%

Australian Fire Danger Rating System: implementing fire behaviour calculations to forecast fire danger in a research prototype†

Kenny,

Matthews,

Sauvage

et al. 2024

Self Cite

Background The Australian Fire Danger Rating System (AFDRS) was implemented operationally throughout Australia in September 2022, providing calculation of fire danger forecasts based on peer-reviewed fire behaviour models. The system is modular and allows for ongoing incorporation of new scientific research and improved datasets. Aims Prior to operational implementation of the AFDRS, a Research Prototype (AFDRSRP), described here, was built to test the input data and systems and evaluate the performance and potential outputs. Methods Fire spread models were selected and aligned with fuel types in a process that captured bioregional variation in fuel characteristics. National spatial datasets were created to identify fuel types and fire history in alignment with existing spatial weather forecast layers. Key results The AFDRSRP demonstrated improvements over the McArthur Forest and Grass Fire Danger systems due to its use of improved fire behaviour models, as well as more accurately reflecting the variation in fuels. Conclusions The system design was robust and allowed for the incorporation of updates to the models and datasets prior to implementation of the AFDRS.

“…This was followed by meteorological fire danger tables (Foley 1947) and 'difficulty of suppression tables' in southern Australia (Douglas 1957). See Hollis et al (2024b) for an extensive overview on fire danger ratings in Australia.…”

Section: Introductionmentioning

confidence: 99%

“…Please refer to fig. 3 in Hollis et al (2024b) for the components of the AFDRS RP . More broadly, the architecture of the AFDRS was intended to comprise four modules, as noted in articles accompanying this one: (1) a fuel state editor, allowing fire and land managers to input current fuel information for use in subsequent fire danger calculation; (2) a calculation engine, in which fire danger calculations are made based on forecast weather and fuel state; (3) a fire danger viewer, enabling interactive visualisation of weather and fire danger forecasts, including red flags; and (4) a seasonal outlook module, presenting maps of subseasonal to seasonal fire danger forecast information.…”

Section: Introductionmentioning

confidence: 99%

Live trial performance of the Australian Fire Danger Rating System – Research Prototype†

Grootemaat,

Matthews,

Kenny

et al. 2024

Self Cite

Background The Australian Fire Danger Rating System program (AFDRS) has built a new fire danger rating system for Australia. A live trial of the system’s Research Prototype (AFDRSRP), based on fire behaviour thresholds, was run and evaluated between October 2017 and March 2018. Aims Live trial results are critically analysed, and knowledge gaps and recommendations for future work discussed. Methods Australian bushfire experts assessed wildfires and prescribed burns across a range of vegetation types and weather conditions. Forecast fire danger ratings calculated using: (1) AFDRSRP; and (2) Forest Fire Danger Index (FFDI) and Grassland Fire Danger Index (GFDI) were compared against ratings derived by expert opinion for each evaluation fire (n = 336). Key results Overall performance of AFDRSRP was superior to the FFDI/GFDI system (56 vs 43% correct), with a tendency to over-predict rather than under-predict fire potential. AFDRSRP also demonstrated its value to assess fire danger in fuel types not conforming to current grassland or forest models; e.g. for fuels that were grouped to use mallee-heath, spinifex and shrubland fire spread models. Conclusions The AFDRSRP live trial was successful, outperforming the existing operational fire danger system. Implications Identified improvements would further enhance AFDRSRP performance, ensuring readiness for operational implementation.