This presentation will describe results from a very high resolution numerical weather prediction (NWP) simulation of the South Australian fire weather of 11 January 2005. The simulation was performed using the Australian Community Climate Earth Simulation System (ACCESS), and involved a sequence of nested limited area model (LAM) runs embedded in the ACCESS global model run. Our analysis of the simulation will focus on how well it captures the meteorological factors that promote extreme fire behaviour, including abrupt surface drying (Mills 2008). The sensitivity of the results to model initialisation (i.e., starting times for the numerical integration) will also be assessed.

The timing of the wind change across the southern Eyre Peninsula in the 0.012°-resolution simulation is within 30 minutes of that given in the Bureau of Meteorology's post-event analysis. The 0.004°-resolution simulation shows indications of boundary-layer rolls and small-scale vortices on the wind change similar to those seen in our previous Black Saturday (7 February 2009) simulations.

These results again demonstrate the ability of high-resolution ACCESS to predict the weather very accurately, and with an unprecedented level of detail. The implications of these advances for understanding fire behaviour, and for improving community and firefighter safety, will be discussed.

This work forms part of a project, funded by the Bushfire Cooperative Research Centre, which aims to produce very high resolution simulations of significant recent fire events, so as to (i) better understand the meteorology of those events and (ii) support the research of other Bushfire CRC project components by providing relevant meteorological data. Intended downstream applications of these results include inputs to fire intensity and spread models, fire decision support tools, understanding and predicting smoke dispersion, and understanding and predicting small-scale weather variability relevant to fire behaviour.

Reference: G A Mills (2008). Australian Meteorological Magazine 57 299-309.