|Title||Modelling the Fire Weather of the Coonabarabran Fire of 13 January 2013|
|Publication Type||Conference Paper|
|Year of Publication||2015|
|Authors||Fawcett, RJB, Yeo, C, Thurston, W, Kepert, JD, Tory, KJ|
|Conference Name||Bushfire and Natural Hazards CRC and AFAC Wellington Conference 2014|
We will exhibit state-of-the-art high-resolution numerical weather prediction simulations and radar imagery for Sunday 13 January 2013, with a specific focus on the region of the Coonabarabran fire which started at around 1600 Eastern Daylight Time (EDT) on 12 January in the Warrumbungle National Park. The simulations show a complicated range of meteorology including weather features that would affect fire behaviour critical for fire-fighter safety.
Features such as convection outflow gust fronts are displayed in the simulations in the north-westerly wind ahead of the main wind change, together with boundary-layer rolls, and sea-breeze-like wind changes proceeding inland from the coast. In addition, small-scale vortices are modelled on the main change: these lead to hazardous local spikes in the modelled Forest Fire Danger Index. Exceptionally strong north/south temperature gradients were observed over inland New South Wales on the Sunday and these are also seen in the simulations.
Sunday 13 January brought difficult conditions for fire fighting. When the fire was declared “out” on 24 January, it had burnt an area of 55,210 ha west of Coonabarabran, 53 homes, 131 other buildings and 95% of the Warrumbungle National Park.
The simulation has been performed using the Australian Community Climate and Earth-System Simulator (ACCESS), and involves a sequence of nested limited area model runs embedded in the ACCESS global model run, with a finest grid spacing of 550 m. Our analysis will focus on how well the simulations capture the meteorological factors that promote extreme fire behaviour. The ACCESS model is used at the Bureau of Meteorology for operational numerical weather prediction, but is used here in research mode at resolutions much finer than current operational ones.