The Bureau of Meteorology (BoM) has forecasted more extreme rainfall to come, similar to the events that hit southeast Queensland and northern New South Wales in February and March.
In recent decades, BoM has reported a trend towards a greater proportion of high-intensity, short-duration rainfall events, especially across northern Australia.
The Insurance Council of Australia (ICA) has reported that the February-March rainfall is the nation’s costliest flood in history, with an estimated $3.35 billion in insured losses. According to RACQ, the flood also ranks fifth in the costliest natural disaster to ever hit Australia, behind only the Eastern Sydney Hailstorm of 1999, Cyclone Tracey of 1974, Cyclone Dinah of 1967, and the Newcastle Earthquake of 1989.
“The intensity of short-duration (hourly) extreme rainfall events has increased by about 10% or more in some regions in recent decades, with larger increases typically observed in the country's north,” BoM said in a special climate statement on the February-March floods. “As the climate warms, heavy rainfall events are expected to continue to become more intense.”
In fact, the February-March flooding had broken several records, with more than 50 sites experiencing over one metre of rain in a week. The heavy rainfall also led to alarming river and creek level rises, which resulted in significant flooding across Brisbane and Ipswich.
By the end of May, RACQ had received more than 15,000 insurance claims – 12,393 of which are property claims and 2,662 of which are motor claims – paying out almost $86 million to members
The full BoM special climate statement can be read here.