Issued on 5 September 2014 by the National Climate Centre
Rainfall deficiencies ease in central eastern Australia, worsen in the south and west
August rainfall was well-below-average across southern Australia with unusually persistent and strong highs, while two significant low pressure systems resulted in well-above average rainfall over much of inland New South Wales and Queensland and almost the entire east coast strip, although rainfall over areas experiencing deficiencies was not sufficient to cause dramatic change.
Deficiencies at the shorter timescale have eased somewhat along the east coast, although Western Australia’s sixth-driest August on record caused an increase in the number of locations experiencing deficiencies along the western and southern coast. Deficiencies at the longer timescale have also increased in central and western Victoria and remain similar elsewhere.
9-month rainfall deficiencies
Though August rainfall was above average over coastal eastern Australia, northern New South Wales and much of Queensland, these falls are above average for the dry season — the actual totals were low away from the coast and have not had a significant impact on long-term rainfall deficiencies. Rainfall deficiencies for the 9 months from December 2013 to August 2014 have decreased in extent and severity over southeastern Queensland and northeastern New South Wales, while dry conditions have seen these increase along the southwest and southern coasts of Western Australia. Serious and severe deficiencies (lowest 10% and 5% of records) are present in a large area of northeastern New South Wales and greater southeastern Queensland as well as isolated pockets in other parts of Queensland, small areas along coastal parts of Western Australia, along the west coast south of around Carnarvon and the south coast to just east of Esperance.
Much of northeastern New South Wales and greater southeastern Queensland also shows serious or severe deficiencies for the 12 months from September 2013 to August 2014.
23-month rainfall deficiencies
Rainfall deficiencies for the 23-month (October 2012 to August 2014) period have remained largely unchanged across Australia when compared to the 22-month period ending July. The only area where rainfall deficiencies have slightly changed is in western Victoria where deficiencies have increased in spatial extent and severity.
Serious and severe deficiencies (lowest 10% and 5% of records) remain in an area spanning much of Queensland away from the eastern coast and also in smaller areas in adjacent parts of the Northern Territory and South Australia, and in an area inland of the Great Dividing Range extending from southern Queensland into northern New South Wales. The area of deficiencies in inland western Victoria has again increased in size compared to the previous Drought Statement, in line with drier conditions which have prevailed in the region in the months since the wetter-than-average April.
More generally, rainfall for the 23-month period ending August 2014 has continued to be below average over the eastern mainland and parts of Tasmania. There are large areas of Australia which have seen rainfall which is below-average but above the lowest 10% of records, highlighting that the spatial extent of below-average rainfall in the southwest and eastern parts of Australia is widespread on this timescale.
Upper layer weekly soil moisture for the week ending 31 August was below to very much below average across much of Victoria and the mainland south coast, Tasmania and western parts of Western Australia. Soil moisture was above average along the east coast of New South Wales and southern Queensland, from inland central New South Wales through to central northern Queensland, and also along the coastal Pilbara and Kimberley in Western Australia. The increase in upper layer soil moisture in central New South Wales into Queensland and a decrease in Victoria and western parts of Western Australia is largely representative of August rainfall patterns.
Lower layer weekly soil moisture for the week ending 31 August remains similar to last month, with a slight increase across the Cape York Peninsula. Soil moisture was below average across parts of inland and southeastern Queensland, northeastern New South Wales, along the west coast of Western Australia extending from the Pilbara to the Central Wheat Belt and in the central Top End. Soil moisture is above average across the central Cape York Peninsula, central Northern Territory and much of the western half of Western Australia as well as pockets of the coastal Top End. Soil moisture is also above average along the south coast from the Nullarbor Plain through South Australia and western Victoria with slightly above-average soil moisture in far eastern Victoria, eastern Tasmania and scattered patches of the mainland southeast.