Wetter conditions brought on by La Nina have not entirely extinguished the threat of bushfire breaking out this coming autumn, according to a report released today.

Pockets in south-east Queensland, south-west Tasmania and southern WA face normal to elevated dangers as conditions there remain dry and warm, having missed out on the unusually heavy rainfall experienced in the last several months, the Bushfire and Natural Hazards Cooperative Research Centre says.

“The influence of La Nina on Australia’s climate has had a pronounced effect on fire potential,” the centre says in its Australian Seasonal Bushfire Outlook: March - May 2021 report.

“Spring and summer have seen average to above-average rainfall across much of the country, with the exceptions of south-east Queensland, south-west Tasmania and parts of southern WA.

“Although La Nina has reached its peak, it is still expected to influence Australia’s climate into autumn, with above average rainfall likely over much of the country.”

The centre says fire risk in large parts of eastern Australia has eased due to significant rainfall during spring and summer.

However southern SA and south-west WA have generally seen drier and warmer conditions in recent months. Areas such as south-west WA have seen reduced rainfall over a multi-year timescale and did not see the extended average to above average rainfall that some regions in eastern Australia experienced last year.

“More rainfall is needed across many areas to fully recover from the extreme dry of spring and summer in 2019/20,” the centre says.

“The tendency towards fire seasons with more frequently elevated fire dangers and for elevated fire danger to occur earlier and later in the season is a clear trend in Australia’s climate, reflecting reduced and/or less reliable cool season (April to October) rainfall in southern parts and rising temperatures.”

According to the centre, La Nina is expected to return to a neutral state in autumn. The climate event typically increases the likelihood of above-average rainfall across much of the country during spring, and the eastern regions in summer and early autumn.

The tropical cyclone season, which ends officially in April, remains a threat, the centre says. While the season has been subdued to date, March is historically the most active month for tropical cyclone occurrence across the country.

“While this may increase the chance of rainfall across northern Australia, including inland regions, areas of increased wind could potentially interact with any fires in the south of the country,” the centre says.

Click here for the outlook.