Australia & New Zealand: Severe deficits forecast in Tasmania

25 May 2017

The Big Picture
The 12-month map (below) indicates severe to exceptional water deficits in large pockets of Northern Territory, northern Queensland, the southwest coast of Western Australia, Tasmania, and New Caledonia.

Surpluses reaching exceptional severity are forecast in a large block in the north from eastern Kimberly past Lake Argyle into Northern Territory. Surpluses are also forecast in northeastern Queensland west of Rockhampton.

Impacts
Citing dry conditions, some farmers in southwestern West Australia are electing to delay planting canola crops or consider abandoning canola altogether and switch to cereals. The drought has also created a lack of livestock feed, spurring a surge in sheep stock off-loading: a record 32,000 sheep sold in one day. Even farmers in the Ravensthorpe region, which was hit by floods three months ago, are looking for more rain as seeding rigs kick up dust. The flooding etched deep gullies in cropland, which farmers must now fill before planting.

Though conditions have improved in Queensland, nearly 70 percent of the state remains under drought declaration, down from a record 87.5 percent. Autumn rains helped but AgForce Queensland chief executive Charles Burke stressed ". . . for one year of drought, it takes two years to recover." After four years Etheridge Shire in far north Queensland has finally had its drought designation removed. Concerns remain high, however, for grain and cotton growers in southeast Queensland west of Brisbane.

Record rainfall for a single day in May was recorded on May 19 in several coastal towns in north Queensland: 120 mm (4.7 inches) in Collinsville and 111mm (4.4 inches) in Proserpine.

A combination of extremely wet weather and warm temperatures have left a vile-smelling brew across parts of New Zealand. Flooding in Waikato and Auckland brought silt, organic matter, and bacteria together to percolate into a stinky mess leaving fields and residential property smelling like a sewage treatment pond.

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

As is apparent in the map series, the forecast indicates that Australia will transition away from widespread and intense water deficits observed February through April. However, severe to exceptional deficits are forecast May through July and longer in southwestern Western Australia, the Darwin Region of Northern Territory, and Tasmania. Moderate deficits with pockets of severe to extreme deficits are forecast for New South Wales, Victoria, much of the Cape York Peninsula in northern Queensland, and New Caledonia.

Surpluses reaching exceptional severity are expected to persist in northeastern Queensland west of Rockhampton. A large block of surpluses in eastern Kimberly, Western Australia will transition to both deficits and surpluses, as illustrated in pink.

From August through October deficits will retreat in Australia, leaving much of the country in near-normal conditions. However, severe to exceptional deficits will continue to emerge in Tasmania and in Darwin Region, Northern Territory. Moderate to occasionally extreme deficits are forecast for the southwest coast of Western Australia and for much of Cape York Peninsula in northern Queensland. Surpluses will continue to emerge near Rockhampton in northeastern Queensland, though the extent of surpluses will diminish. Surpluses are forecast to re-emerge in a large block of Kimberly Region in the north, along with conditions of both deficit and surplus.

The forecast for the final months – November through January – indicates primarily mild deficits in the region, with the exception of Tasmania where more severe deficits will persist.

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