Model predicted spread rates for the Sydney January 1994 fires

Wildfires from 27 December 1993 to 14 January 1994 occurred along most of the southeast coast of Australia. More than 800,000 hectares of land were affected, 205 houses destroyed and three people perished. The most extensive fires were near Sydney and there were many small but intense bushfires in suburbs, even close to the city centre.

The fire weather leading up to the worst of the fire days in the Sydney area, namely January7-8, has already been simulated, successfully capturing vital detailed information on wind speed and direction, relative humidity and temperature patterns both near the surface and above the boundary layer. The simulations also produced skilful predictions of the Forest Fire Danger Index.

In this study the emphasis is on simulating the observed rates of fire spread using a simple relationship between fuel height and meteorological model parameters using an atmospheric mesoscale model developed by one of the authors (LML). The parameters are based essentially on low level wind speeds (10 metres above ground level) and orography.

Results will be presented on maps which show the simulated rate of spread compared to the observed rate for two fires which started in the Royal National park just south of Sydney and near the Bell's Line of Road in the Blue Mountains to the west of Sydney, respectively. Also, re-analyses incorporating weather observations close to the fires will be produced in order to re-initialise and re-run the NWP model and then compare the results of the simulation without the additional data.