Issued on 3 December 2014
Rainfall deficiencies generally increase across eastern Australia
November rainfall was below to very much below average for eastern Australia and much of the Top End. Monthly rainfall was in the lowest ten per cent of records (decile 1) for most of northern Tasmania and most of the Cape York Peninsula in Queensland, as well as other scattered areas in the east and centre of Queensland and New South Wales. Rainfall has been below average across large parts of eastern Australia for most of 2014; rainfall deficiencies across parts of the east have been exacerbated by particularly dry conditions during the past two months. Overall, rainfall during the second half of the southern growing season (July to November) has been below to very much below average across most of southeast Australia, coinciding with record-warm temperatures.
5-month rainfall deficiencies
For the 5-month period (July–November 2014), below-average November rainfall across much of eastern Australia has increased the area of serious and severe rainfall deficiencies along and inland of the Great Dividing Range in New South Wales extending into southeastern Queensland, across the central and southern Cape York Peninsula in Queensland and also in northwestern Tasmania. Serious and severe deficiencies also persist across the agricultural region of South Australia and the western half of Victoria, southern New South Wales, the Top End and scattered areas around central Australia, although rainfall in the past month has reduced or alleviated deficiencies north of Carnarvon and near Giles in Western Australia, in the northwest and east of the Northern Territory and across western Queensland.
12-month rainfall deficiencies
The extent of rainfall deficiencies in eastern Australia has also increased at the 12-month scale (December 2013 – November 2014). Deficiencies are in place over much of western Victoria and adjacent southeastern South Australia, along the east coast of Tasmania and in smaller areas of the west coast, and in a broad area of northeastern New South Wales and southeastern Queensland where the area affected by severe deficiencies (lowest 5% of records) has also increased. Scattered pockets of serious deficiencies (lowest 10% of records) also remain between northeastern South Australia and Queensland's tropical coast, and in the central Top End, southwest of the Northern Territory and on Western Australia's west coast.
26-month rainfall deficiencies
At the 26-month (November 2012 – November 2014) timescale, serious and severe rainfall deficiencies persist across much of Queensland away from the eastern coast, extending into inland northeastern New South Wales, the southwest of the Northern Territory and northeast South Australia. Rainfall in the past month has slightly decreased deficiencies around the western border of Queensland while deficiencies in the remainder of this area have generally increased slightly.
Serious and severe deficiencies have also slightly increased where they persist over most of the western half of Victoria, excluding the area immediately along the coast and New South Wales border, adjacent parts of southeastern South Australia, and in an area of the southern coastal Gascoyne around Shark Bay in Western Australia.
November typically sees the start of moderate rainfall totals occurring along the east coast of Queensland as the northern wet season develops; a late start to the wet season this year would make removal of these longer-term deficiencies in Queensland less likely as they are largely the result of below-average rainfall over the two preceding wet seasons. The northern wet season spans October–April; rainfall will have to be above average over much of the remaining months to April to lift these areas out of deficiency, i.e. above the tenth percentile.
Upper layer weekly soil moisture for the week ending 30 November was very much below average across the Top End, eastern Queensland, most of New South Wales, parts of eastern Victoria and from western Victoria through coastal South Australia, and also across northern and eastern Tasmania and in small areas along the west coast of Western Australia. Following recent rainfall upper layer soil moisture is above average across much of northwest Australia, extending through Western Australia from the Pilbara to the south coast, and is also above average for smaller areas south of the Gulf of Carpentaria, in western Queensland and the south of the Northern Territory, and through southern New South Wales and adjacent South Australia.
Compared to last month, lower layer weekly soil moisture for the week ending 30 November has decreased across eastern Australia, the far north and the southwest. Lower layer soil moisture is below average across parts of central and a large area focused on southeastern Queensland and the northeastern half of New South Wales, extending along the Great Dividing Range and parts of southern New South Wales across much of northeastern Victoria then across the western half of Victoria and adjacent southeastern South Australia. Soil moisture is also below average for most of northern and eastern Tasmania, along the west coast of Western Australia and through the central Top End. Soil moisture remains above average in the eastern central Cape York Peninsula, central Northern Territory and much of the eastern half of Western Australia as well as in parts of coastal South Australia, mostly in the west.