Issued 4 December 2015
Generally little change to rainfall deficiencies following mixed November rainfall
November rainfall was near average for Australia as a whole. Rainfall was below average for southwest Western Australia, much of southern Victoria and adjacent far southeastern South Australia, Tasmania, the Top End, and other pockets of northern Australia. Rainfall was above average for large areas of Western Australia, central and eastern South Australia, and New South Wales.
Deficiencies have increased in part of far southwest Western Australia at the 38-month, 17-month, and 7-month timescales. Deficiencies have decreased somewhat along parts of the border between Victoria and New South Wales and in parts of agricultural South Australia at all timescales, though remaining generally similar to the last Drought Statement in most of the rest of those States. In Tasmania, rainfall deficiencies have increased at each of the three monitored timescales.
Changes to rainfall deficiencies in Queensland were mixed, following the pattern of monthly rainfall, with rainfall deficiencies either increasing or decreasing in small areas, although with little large-scale change to the overall areas experiencing deficiencies.
Rainfall in eastern Australia has been very much below average for large areas for periods of about 3 years' duration (since the conclusion of the last La Niña in autumn 2012). Long-term deficiencies also exist in eastern Australia over the 17 years since 1998.
Rainfall for the southern wet season, which spans April to November, was below average for most of Victoria, southeastern South Australia, Tasmania, across the South West Land Division in Western Australia and parts of the Gascoyne. For the most recent 3-months (September to November) rainfall was below to very much below average for most of the South West Land Division and Southeast Coastal district in Western Australia; southeastern South Australia and Victoria; western South Australia and the south of the Northern Territory; most of the Top End; large parts of Queensland; and lowest on record for much of Tasmania. A longer discussion is provided in the seasonal climate summary for spring.
7-month rainfall deficiencies
Rainfall deficiencies at the 7-month timescale (May to November 2015) decreased in areas across northern Victoria and the Mid North district of South Australia, and also decreased in some parts of Queensland's Central Coast. Deficiencies have increased in Tasmania, particularly the northwest, and in parts of the southwest of the Northern Territory and the far southwest of Western Australia. Rainfall deficiencies have also emerged in the coastal southeast of the Top End.
Overall, serious or severe rainfall deficiencies (lowest 10%, or lowest 5% of historical records) are present over most of southwest Western Australia (the area southwest of a line between Jurien Bay and Bremer Bay); southeastern South Australia and most of Victoria away from the north and eastern Victoria; eastern, northern and coastal western Tasmania; an area of Queensland extending inland from the Central Coast district, and smaller pockets between this region and the southwest of the Northern Territory; and also in the northwestern Top End and on the coast of the Roper–McArthur district of the Northern Territory. A broader region around these areas has experienced below-average rainfall for the same period, without dipping into serious rainfall deficiencies.
17-month rainfall deficiencies
For the 17 months July 2014 to November 2015, deficiencies have increased in southwestern Western Australia, northwestern South Australia and northwestern Tasmania. Deficiencies have also increased slightly in most of the affected areas of Queensland, except the Central Coast and adjacent inland region. Rainfall deficiencies have decreased slightly across northern Victoria and the hinterland of southern South Australia.
Severe or serious deficiencies (lowest 5% or lowest 10% of historical records) persist in an area extending from northwestern South Australia, along the coast of South Australia, and across most of Victoria except Gippsland and parts of the northeast. Rainfall for the period remains lowest-on-record for an area spanning southeastern South Australia and adjacent parts of western Victoria. Serious or severe deficiencies also persist across most of Tasmania except an area of the southeast; western parts of the South West Land Division in Western Australia; parts of northern Queensland between the southern Gulf Coast, across the Cape York Peninsula, and in an area of inland central Queensland near Longreach.
Much of southeastern Australia has seen below-average April–November rainfall during three of the last four years, with monthly rainfall also below average from August last year for much of this region (apart from well-above-average January rainfall, above-average March and May rainfall in Tasmania, and above-average November rainfall in large parts of New South Wales and the eastern half of South Australia except the southeast).
38-month rainfall deficiencies
At the 38-month timescale (October 2012 to November 2015), rainfall deficiencies have increased slightly in far southwest Western Australia, northwestern and eastern Tasmania, central western Victoria, and some central parts of the affected region in Queensland. Deficiencies have decreased slightly in some parts of northwestern and north-central Victoria, and remain similar to the last Drought Statement in other areas.
Severe or serious deficiencies (lowest 5% or lowest 10% of historical records) persist in an area spanning southeast South Australia and the western two thirds of Victoria; areas of the west and east coasts of Tasmania; most of South West Western Australia (the area southwest of a line between Jurien Bay and Bremer Bay); and across large parts of Queensland south of the Cape York Peninsula and away from the southeast, extending into part of northern New South Wales to the west of the Great Dividing Range.
Deficiencies also persist at a range of even longer timescales, with most of eastern Australia having received below-average rainfall following the conclusion of the 2010–12 La Niña events, and large parts of Queensland having experienced poor wet-season rainfall in successive years.
Soil moisture information presented here is from the Bureau's operational Australian Water Resources Assessment Landscape (AWRA-L) model, developed through the Water Information Research and Development Alliance between the Bureau and CSIRO. More information on the model used and the totals that the decile ranges represent can be found at the new Australian Landscape Water Balance website. Previous Drought Statements used soil moisture maps from the CSIRO (AWAP) water balance suite.
Lower-layer soil moisture (10 cm to 100 cm) for November 2015 was below to very much below average over Tasmania; southwest Western Australia (the area southwest of a line between Jurien Bay and Bremer Bay); southeastern South Australia and most of Victoria, except the northwest, central northern regions, and East Gippsland; parts of northwestern South Australia and the southwestern Northern Territory; other parts of the Northern Territory in the Top End and east; and scattered small areas in Queensland.
Lower-layer soil moisture was above average for much of Western Australia and adjacent parts of the eastern Northern Territory; large parts of the eastern half of South Australia, excluding the southeast; much of New South Wales, excluding most areas along the Great Dividing Range and western regions; and also in scattered areas of Queensland. An increase in lower-layer soil moisture over New South Wales and Queensland resulted from rainfall in November, particularly earlier in the month.
Lowest on record - lowest in the historical analysis, which runs from 1900.
Severe deficiency - rainfalls in the lowest 5% of historical totals.
Serious deficiency - rainfalls in the lowest 10% of historical totals, but not in the lowest 5%.
Very much below average - rainfalls in the lowest 10% of historical totals.
Below average - rainfalls in the lowest 30% of historical totals, but not in the lowest 10%.
Average - rainfalls in the middle 40% of historical totals.
Above average - rainfalls in the highest 30% of historical totals, but not in the highest 10%.
Very much above average - rainfalls in the highest 10% of historical totals.
Product Code IDCKGD0AR0