With bush fires burning hundreds of thousands of hectares in the populous Australian state of New South Wales, a recent study indicates that a Fire Danger Meter used since the 1960s by firefighters there to predict prescribed fire spread in eucalyptus forests is inaccurate under wildfire conditions.

The meter could under-predict the rate of fire spreading in forests by a factor of 3 or more for extreme fire conditions or when wind speeds are greater than 15 kilometers per hour, according to the report by Project Vesta. The project is a 6-year endeavor by Australia's Commonwealth Scientific and Industrial Research Organisation (CSIRO), in collaboration with the Western Australian Department of Conservation and Land Management (CALM), and land management agencies and fire authorities in other Australian states.