Australia & New Zealand: Water deficits forecast to persist in Tasmania

September 26, 2016

The Big Picture
The 12-month composite map (below) indicates water deficits forecast in Tasmania; the southwest tip of Western Australia; coastal South Australia west of Spencer Gulf; from Adelaide to Victoria; North Island, New Zealand; and New Caledonia. Surpluses are forecast in central Queensland.

Impacts
New Caledonia has seen 70 per cent less rainfall than normal so far this year. The country's Civil Security has declared a ban on fires, with the exception of cooking fires, after drought conditions in Belep were declared extreme and 80 percent of New Caledonia is at heightened risk.

Record winter rains have brought some relief to drought-ravaged western Queensland. Longreach received five times its normal winter rainfall this year, recording 262mm (10.35 inches). Though the rain has encouraged some graziers to bring back livestock that had been de-stocked due to prolonged dry conditions, other farmers in the region are continuing with plans to leave the area.

One unexpected positive consequence of drought in the Outback has been the growing tourism spurred by the discovery of dinosaur bones and fossils. Up to 1,000 visitors per year have been drawn to Richmond - more than the town's population - where bones of an ichthyosaur and kronosaurus were recently unearthed.

State Emergency Services in Victoria have issued advisories concerning flooding on several rivers in Victoria including the Avoca, Hopkins, Loddon, Ovens, King, Barwon, Glenelg, Goulburn, and parts of the Murray. One drowning was reported in Wallacedale.

Forecast Breakdown
The 3-month composite (below) for the same 12-month period shows the evolving conditions in more detail.

The September through November map shows exceptional deficits in the northernmost region of the Northern Territory along with deficits of lesser severity elsewhere across northern Australia. Moderate to exceptional deficits are forecast to persist in: the southwest tip of Western Australia south of Perth; from Adelaide through Melbourne; Tasmania; and New Caledonia. Deficits are forecast to emerge on South Island, New Zealand. Exceptional surpluses are forecast to persist in central Queensland. Primarily moderate surpluses are expected to emerge in parts of the Murray-Darling Basin, including the Upper Murray River catchment in southern New South Wales along the New South Wales-Victoria border, and the northeastern tributaries of the Darling west of Brisbane, Queensland.

A transition from deficits to moderate surpluses is forecast December through February in northern reaches of Western Australia into Northern Territory, while conditions in New Zealand normalize after months of various water anomalies. Surpluses forecast in prior months for central Queensland and the Murray-Darling Basin are no longer evident except in small, isolated pockets. Primarily moderate deficits are forecast to persist south of Perth, between Adelaide and Melbourne, and in Tasmania.

The final months – March through May – show a forecast of abnormal (3 to 5 years) deficits persisting across much of Australia with moderate deficits across the far north, south of Perth, from Adelaide to Canberra, Tasmania, and North Island New Zealand.

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