Australia: Intense water deficits to persist in Busselton, WA & Tasmania

26 September 2017

The Big Picture
The 12-month map (below) indicates a forecast of significant deficits in many regions of Australia. Deficits are expected to reach severe to exceptional intensity in the southwest corner of Western Australia, much of South Australia, the southern half of Northern Territory, western Queensland, central New South Wales, Victoria, Tasmania, and New Caledonia.

Scattered moderate deficits are forecast for southern New Zealand.

Impacts
Australia's 2017 winter was the hottest since record-keeping began in 1910, with an average maximum daily temperature for June, July, and August of 23.7°C (74.7°F), reports the Bureau of Meteorology, 1.9°C (3.42°F) above the baseline 1961 to 1990 average.

Forecasts for the country's wheat harvest have dropped even lower than estimates made last month. Citing drought overall and both drought and frost in New South Wales, Abares, the Australian commodities bureau, now projects a 9-year low for the wheat harvest and a 7-year low for canola. The National Australia Bank went even further, forecasting wheat at a 10-year low.

To ease grain shortages in northern New South Wales and southern Queensland, interstate bulk grain shipments from South Australia are being considered.

Some graziers in dry, southeast Queensland have already destocked or moved cattle and now face the decision of whether to euthanize animals weakened from lack of fodder. About 66 percent of Queensland has been drought-declared. Growers and graziers in southern Tasmania describe the situation as "desperate" as they watch the wind blow away soil so dry it won't support the growth of pasture.

Increasingly, rural communities in Australia devastated by drought and facing population loss, are creating incentives for immigrant groups to help fill farm and other labor shortages. Mildura, located in the farming region of Sunraysia in Victoria, has donated farmland to migrants from Burundi in an effort to meet demand for locally produced organic crops, a skill compatible with traditional Burundi farming.

Forecast Breakdown
The 3-month maps (below) for the same 12-month period show the evolving conditions.

As is apparent in the time series above, exceptional deficits observed in recent months over much of Australia are forecast to diminish considerably in the near-term and through May 2018. However, severe to exceptional deficits are forecast to persist in Tasmania through February, as are deficits in the southernmost tip of Western Australia.

In addition, from September through November moderate to severe deficits are forecast from the Yorke Peninsula in South Australia along the southern coast through Victoria and New South Wales and in the eastern Murray-Darling Basin. Exceptional deficits are expected to persist in North Territory’s Top End, with moderate deficits tracing the southern shore of the Gulf of Carpentaria and into northern Queensland, where more severe pockets are expected. Both deficits and surpluses are forecast for the Ord River Basin and the Victoria River in the north, with moderate deficits to the west through the Great Sandy Desert to the Hamersley Range. Along Queensland’s northeast coast surpluses will persist west of Mackay, with both deficits and surpluses south of Rockhampton. Some moderate deficits will emerge in southern South Island, New Zealand, and exceptional deficits in New Caledonia will downgrade to severe.

The December through February forecast indicates the persistence of intense deficits in Tasmania and in the southernmost tip of Western Australia. A large block of deficits is forecast to emerge in the southeast corner of Northern Territory reaching down through South Australia. Deficits across northern Australia and in Victoria and New South Wales will downgrade to primarily moderate, as will deficits in New Caledonia. Moderate deficits will continue to emerge on South Island, New Zealand and will emerge in western North Island.

The forecast for the final months, March through May, indicates primarily mild deficits throughout the region.

(It should be noted that forecast skill declines with longer lead times.)

Note on Administrative Boundaries
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