Issued at 10:30am, Wednesday 25 May 2022
The Bureau of Meteorology has released a formal record of the extreme rainfall and flooding that occurred in south-east Queensland and eastern New South Wales in February and March this year.
Special Climate Statement 76 outlines that several rainfall records were broken between 22 February and 9 March 2022, with more than 50 sites recording more than one metre of rainfall in one week.
In the last week of February, parts of south-east Queensland and north-east New South Wales had rainfall 2.5 times their monthly average with some regions recording more than five times their monthly average.
After two years of La Niña conditions, the rain fell on saturated catchments leading to flash and riverine flooding extending from Maryborough in Queensland to Grafton in New South Wales.
For many areas, this was the wettest week since at least 1900. Some areas of south-eastern Queensland had their highest flood peaks since 1893, though the lower Brisbane and Bremer rivers and Lockyer Creek peaked below the levels of both January 1974 and January 2011 floods.
In parts of northern New South Wales, flood levels broke previous records. Wilsons River in Lismore peaked at a record high level, estimated to be 14.4 m on 28 February. The previous record was 12.27 m in February 1954.
The rainfall was the result of a combination of weather systems over eastern Australia and the Tasman Sea, where a large volume of humid tropical air moving onshore over eastern Australia was lifted in the atmosphere to produce heavy rain and thunderstorms.
In recent decades, there has been a trend towards a greater proportion of high-intensity, short-duration rainfall events, especially across northern Australia.
The Bureau’s special climate statements provide detailed summaries of significant weather and climate events that impact Australians. This Special Climate Statement has been added to an archive of Special Climate Statements dating back more than 15 years, providing easy access to data and information.
Special Climate Statement 76 can be found here: https://www.bom.gov.au/climate/current/statements