Large areas of Australia face above normal fire potential this summer as saturated ground supports vegetation and fuel load growth.
The Australasian Fire and Emergency Services Authorities Council (AFAC) says bushfire risk is higher than average in central western and southern WA, central Australia, southern Queensland, inland NSW and western Tasmania.
AFAC’s latest Seasonal Bushfire Outlook says above average rainfall and significant flooding, coupled with expected warmer and drier conditions, is generating varied fire potential for summer, when vegetation will dry out and fire potential may “rise quickly with any extended period of hot, dry and windy weather”.
“It is possible for regions of below normal bushfire potential at the start of summer to transition to normal, or even above normal, bushfire potential later in the season,” AFAC said.
Most of Australia shows normal summer fire potential currently, and areas across Victoria, NSW and the ACT show below normal fire potential due to increased moisture, a continued wet outlook and fuel load reduction in the 2019-20 bushfire season.
In NSW, AFAC says large areas, particularly the state’s west, are facing an above normal fire potential due to prolific grass growth. Persistent above average rainfall will continue to promote grass growth, further adding to existing high fuel loads.
“Early summer fire activity is expected to remain below normal in flood affected regions. However, with an expected return to more normal rainfall conditions over summer, these grass fuels are likely to cure and become more susceptible to fire,” it said.
This will result in an above average fire potential later in summer, with the chance of exceeding average fire danger in grassland areas increasing towards the end of the quarter.
“Very high grass fuel loads could result in larger, more intense fires in NSW despite the onset of cooler weather.”
Above normal fire potential is anticipated in western Tasmania as the flammability of peat soils, moorlands, scrubs, and heaths is predicted to be greater than normal. Lightning strikes in these areas may ignite fires.
In Queensland, overall grass fuel levels are high but soil moisture significant, while in WA, above average temperatures coupled with average to below average rainfall is expected during summer.
“Higher than average non-woody vegetation fuel loads such as fully cured grasses, together with predicted warmer and drier than average summer conditions have resulted in above normal fire potential for parts of the Pilbara, Carnarvon, Gascoyne and Murchison bioregions,” AFAC said.