Communities in the seven local government areas of the NSW Northern Rivers region know where they have been in 2022 and now they know where they are heading - into more rain

ENSO Outlook

An alert system for the El Niño–Southern Oscillation, 24 May 2022

Australian Bureau of Meteorology:

Special Climate Statement 76 - Extreme rainfall and flooding in south-east Queensland and eastern New South Wales, February-March 2022

25/05/2022 - National

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: http://www.bom.gov.au/climate/current/statements

The Guardian, 25 May 2022:

The breakdown of the La Niña weather pattern in the Pacific has stalled while a key Indian Ocean climate driver is tilting towards its wetter phase, making it more likely that eastern Australia will face more heavy rain and floods.

Just as the Bureau of Meteorology released a special climate report on the extreme rainfall and flooding that hit parts of south-eastern Queensland, northern New South Wales and the region around Sydney in February and March, its fortnightly report on climate influences pointed to the big wet extending for months to come.

The La Niña event, already in its second year, could yet persist into a third. The expected dissipation of the pattern has not progressed in the past two weeks, and two of the seven models used by the bureau project that the La Niña will last through winter.

Out west, the Indian Ocean dipole is forecast by all climate models to enter its negative phase in coming months.

That phase of the dipole – which gauges the relative differences of sea-surface temperatures across the ocean – increases the chances of above-average winter-spring rainfall for much of Australia. It also lifts the odds of warmer days and nights for northern Australia, according to the bureau.

Models are becoming more confident that we'll get a negative Indian Ocean Dipole in coming months. That typically results in above-average rainfall for central and eastern Australia. @BOM_au pic.twitter.com/w9Xlp0HYUi

— Peter Hannam (@p_hannam) May 24, 2022

The prospect of wetter than normal conditions for the east coast in particular will prompt fears of further floods. Catchments remain damp and dams are full, so it won’t require significant bursts of rain to cause more flash flooding and damage.

Spot the difference: June-August (left) and July-September show the odds strongly favour above-average rainfall across most of the country in coming months. @BOM_au pic.twitter.com/lBCXkD1PP0

— Peter Hannam (@p_hannam) May 25, 2022

Read the full article here.