Australia & New Zealand: Surplus persists in SE Australia

21 April 2023

THE BIG PICTURE
The 12-month forecast ending in December 2023 anticipates intense surpluses to continue in southeastern and northern regions of Australia. Intense anomalies, mostly deficits, are expected to emerge In Tasmania and New Zealand.

Extreme to exceptional surplus is expected in:

Central to south-central New South Wales, near the city of Griffith.
Northern regions of Western Australia, appearing in areas near the city of Broome.
Eastern regions of Northern Territory, near the Nicholson and Simpson regions. Central areas of the McArthur region will experience moderate to severe surplus.
Central to eastern Queensland, near the coastal regions near the city of Townsville. Areas near the cities of Cairns and Karumba can anticipate moderate to severe surplus.
Northern New Zealand, throughout the North Island and along its eastern coast.

Extreme to exceptional deficits are forecast in the following areas:

Southern Western Australia, in coastal regions near the city of Albany. Places in Northern Western Australia near the Prince Regent River can expect deficits of similar intensity.
Eastern coastal areas of Queensland, near the Girringun National Park.
Southern New Zealand, in southern coastal areas of the Southland district.
Tasmania, with mostly severe deficits occurring in southwestern areas of the country, near the Southwest National Park.

The 3-month maps (below) show the evolving conditions in more detail.

FORECAST BREAKDOWN
The forecast through June 2023 expects intense surpluses in New South Wales to continue, spreading further into areas of western Victoria. Surplus anomalies of similar intensity are expected to persist in northern areas of Western Australia near Broome, as well as in the Northern Territory, in the Nicholson and Simpson regions. The North Island of New Zealand can anticipate surpluses to persist, though they will downgrade from exceptional intensity to severe. Deficits in southern New Zealand and Tasmania are expected to dissipate.

From July through September 2023, surpluses in New South Wales are expected to linger, though surpluses in western Victoria are expected to disappear. Areas near Broome and the Nicholson regions can expect surpluses to continue in moderate to severe intensity. Intense surplus and deficits anomalies in New Zealand are expected to mostly transition into mild deficits scattered throughout the country, however, exceptional deficits are expected to occur along Tasmania’s western coast.

The forecast for the final months – October through December 2023 – anticipates surpluses in New South Wales to continue but shrink. Surpluses across northern Western Australia and the Northern Territory are expected to linger, though also shrinking. Mild deficits in New Zealand are expected to stay, while severe to exceptional deficits in Tasmania are forecast to disappear from the western coast and reappear on the country’s eastern coast.

Please note that WSIM forecast skill declines with longer lead times.

IMPACTS
Due to the damages caused by Eastern Australia’s 2022 floods, the Insurance Council of Australia (ICA) recently raised its estimate of losses to AUD 5.81 billion, an increase of $160 million compared to estimates made in November. The ICA called the flooding the most expensive extreme weather event in Australian history, which caused much destruction in southeastern Queensland and northern New South Wales. ICA CEO Andrew Hall stated, “As the costliest extreme weather event in Australian history, last year’s floods created significant challenges for the insurance industry in addressing the extraordinary volume of claims across a very wide geographic area.”

For the first time in eight years, the development of El Niño in the Pacific Ocean is becoming more probable this year. While the Bureau of Meteorology currently predicts about a 50 percent chance of El Niño developing, the National Oceanic and Atmospheric Administration (NOAA) predicts a 62 percent chance of El Niño developing during May to July 2023. NOAA also predicts it could be one of the strongest El Niño's in decades, which increases the odds of eastern Australia experiencing much drier and warmer weather than usual.

A new study suggests that rising sea levels could lead to flooding of sea turtle breeding grounds in Australia, as well as other countries. The report finds that flooding could contribute to the destruction of turtle nesting sites, citing that leatherback turtle nests may be particularly vulnerable. Authors of the study found that breeding grounds located on flat beaches, such as Raine Island, were most vulnerable to flooding, and were estimated to be vulnerable to flooding by 2050.

NOTE ON ADMINISTRATIVE BOUNDARIES
There are numerous regions around the world where country borders are contested. ISciences depicts country boundaries on these maps solely to provide some geographic context. The boundaries are nominal, not legal, descriptions of each entity. The use of these boundaries does not imply any judgement on the legal status of any territory, or any endorsement or acceptance of disputed boundaries on the part of ISciences or our data providers.

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