Isolated areas of rainfall deficiencies persist in some areas following a wet winter
Rainfall during August 2016 was above to very much above average for most of the country, especially northern and central Australia and parts of New South Wales. Rainfall for the month was below average for eastern Tasmania, southeastern New South Wales, across Gippsland and pockets of the Western district in Victoria, areas of southern South Australia—particularly around the Eyre Peninsula—and parts of Western Australia's Interior district, although rainfall totals are generally low there during August.
Generally above average rainfall in August follows above average rainfall over most of the country in each month since May 2016, providing excellent relief from the multiyear rainfall deficiencies which had developed in the 2012 to 2015 period. However, some small areas continue to experience rainfall deficiencies in southern Victoria and around the northern and western coast. Overall, winter 2016 was the second-wettest for Australia. Most areas now have average to above average soil moisture, and the area of severe and serious rainfall deficiencies is greatly reduced. Higher than average rainfall often occurs following the breakdown of strong El Niño events, and has further been enhanced by the strong negative phase of the Indian Ocean Dipole (IOD) which has persisted since late May.
Soil moisture in the lower layer (from 10 cm to 100 cm deep) remains above average over most of the country.
Soil moisture for August was above average over much of Australia, and very much above average for central Queensland to the western Cape York Peninsula, much of New South Wales west of the Great Dividing Range, a large part of central to eastern Tasmania, and for the Pilbara in Western Australia and western areas of Central Australia.
Soil moisture for the month was below average for part of the South West Land Division in Western Australia and parts of the central Top End.
- Rainfall deficiencies persist in isolated pockets of the northern and western coast and southern Victoria
- Lower layer soil moisture for August was above average over most of Australia
Product code: IDCKGD0AR0
Soil moisture details are reported when there are periods of significant rainfall deficits.
Soil moisture data is from the Bureau's Australian Water Resources Assessment Landscape (AWRA-L) model, developed through the Water Information Research and Development Alliance between the Bureau and CSIRO.
See: Australian Landscape Water Balance.
What is drought?
Drought is a prolonged, abnormally dry period when the amount of available water is insufficient to meet our normal use. Drought is not simply low rainfall; if it was, much of inland Australia would be in almost perpetual drought. Because people use water in so many different ways, there is no universal definition of drought. Meteorologists monitor the extent and severity of drought in terms of rainfall deficiencies. Agriculturalists rate the impact on primary industries, hydrologists compare ground water levels, and sociologists define it by social expectations and perceptions.
It is generally difficult to compare one drought to another, since each drought differs in the seasonality, location, spatial extent and duration of the associated rainfall deficiencies. Additionally, each drought is accompanied by varying temperatures and soil moisture deficits.
Rainfall averages, variability and trends
- Average rainfall: How much rain do you expect?
- Rainfall variability: How consistent is rainfall in your area?
- Rainfall history: Check tables, graphs and data from your local weather station.
- Rainfall trends: Has your rainfall changed?
Lowest on record - lowest since at least 1900 when the data analysed begin.
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.
For the week to 27 September 2016, rainfall was recorded in the Northern Territory in the northwest, south of the Top End, and in the southeast; across much of western, central and southern Queensland; most of New South Wales except the central to northern coast and inland north; most of Victoria and areas of eastern South Australia; much of Tasmania except the southeast; and across the South West Land Division and southern coast of Western Australia.
At the start of the week a broad surface and upper-level trough extended a cloudband from the Top End of the Northern Territory through central Australia, across much of Queensland and inland New South Wales. Showers and thunderstorms formed in the vicinity of the trough resulting in moderate falls across western, central, and southern Queensland, and in the northern and eastern parts of the Northern Territory.
At the beginning of the week a cold front and associated low pressure system tracked across southeast Australia, generating moderate falls in western and southern New South Wales, the northwest pastoral districts of South Australia, and northwest Victoria. The low pressure system tracked eastwards, and deepened over southern New South Wales before moving off the New South Wales coast. Widespread light falls were recorded from southeastern Queensland to eastern Victoria, with moderate falls reported locally across southern New South Wales and in parts of East Gippsland.
From the middle of the week, a series of cold fronts tracked across southern Australia. Light falls were recorded in southwest and southern parts of Western Australia, and across the agricultural district and Flinders Ranges in South Australia. The initial frontal system and an associated trough produced a cloudband with embedded storm cells that tracked across the southeast, and produced mostly light rainfall across New South Wales, Victoria, northern and western Tasmania, and southeastern South Australia. Moderate falls were recorded in parts of Murray Valley in South Australia, and the Wimmera district in Victoria, along with parts of central and western New South Wales.
Rainfall totals between 50 and 100 mm were recorded in parts of eastern Victoria, pockets of western and central New South Wales, isolated parts of the Darwin–Daly region in the Northern Territory, and in central Queensland. The highest weekly total was 80 mm at Pirlangimpi Airport in the Northern Territory.
Rainfall totals between 10 mm and 50 mm were recorded in southwest and coastal southern Western Australia; in parts of the Top End, the Victoria River and Alice Springs districts in the Northern Territory; and across western, central and southern Queensland. Similar totals were also recorded in eastern South Australia and about the Eyre and Yorke Peninsulas, across most of Victoria, western and northeastern Tasmania, and most of New South Wales but generally excluding the coast north of Wollongong and areas of the inland north.
Little or no rainfall was recorded in remaining parts of Western Australia, in the north, west and centre of South Australia, the west and south of the Alice Springs District and south of the Gulf in the Northern Territory, southeastern Tasmania, and northern and eastern Queensland.
Impact of recent rainfall on deficits
Due to above average rainfall in recent months over areas which had experienced deficiencies since mid-2015, no large-scale deficiencies are currently present. Rainfall analyses are available for standard periods out to 48 months.
Product code: IDCKGRWAR0