Weekly Rainfall Update

For the week to 21 November 2017, rainfall was recorded in all States and Territories, except in the Pilbara, northern Gascoyne and central Interior districts of Western Australia.

At the beginning of the week, a large cloudband associated with a cold front and surface trough tracked across southeastern Australia. Thunderstorms and showers produced moderate to locally heavy falls in the eastern half of South Australia, western Victoria, southwestern New South Wales and parts of southern Tasmania. Broad areas of low pressure extended across the north and west of the continent, with showers and thunderstorms developing in the Top End and southern interior of the Northern Territory, the Kimberley, and along parts of the Gascoyne coast of Western Australia.

In the middle of the week, a low deepened over western Victoria, with the associated easterly trough becoming near stationary and extending north through western New South Wales and Queensland to a weak heat low in the Gulf Country. Moderate falls and thunderstorms were recorded in much of Victoria, while light to moderate falls were reported in the eastern half of New South Wales, and in Queensland’s southern and central interior. Thunderstorms and showers produced moderate falls across much of the southeastern quarter of Queensland and in northeastern New South Wales on the following days.

A series of low pressure troughs over northern and central Australia generated thunderstorms and showers, with moderate to locally heavy falls reported in the Kimberley, the west of the Northern Territory and the Top End, the Gulf Country, and Central Australia between the middle and end of the week. At the end of the week a broad area of low pressure developed over the northern interior of Queensland, while a very moist northeasterly airstream directed showers onto the north tropical coast of Queensland. Moderate to locally heavy falls were recorded across much of northern Queensland.

In the west, a cold front with an associated middle level cloudband and embedded thunderstorms tracked over southwest Western Australia during the middle of the week. Light to moderate falls were recorded in the South West Land Division and southern coast of Western Australia.

Rainfall totals exceeding 100 mm were recorded in a small area of the northwest Top End in the Northern Territory, at isolated locations in the east Kimberley District in Western Australia and pockets of the east coast of New South Wales, and north tropical Queensland Coast. The highest weekly total was 153 mm at both Nitmiluk Ridge in the Northern Territory and Bingil Bay in the north tropical coast of Queensland.

Rainfall totals between 50 mm and 100 mm were recorded in parts of the Kimberley District in the Northern Territory; across parts of the Top End in the Northern Territory; in the southern interior, coastal southeast and north tropical coast of Queensland; in pockets of eastern and southern New South Wales; in the far east, north and southwest of Victoria; and a small area of southeastern South Australia.

Rainfall totals between 10 mm and 50 mm were recorded in the South West Land Division, southern coast and Kimberley District of Western Australia; and in the northern half of the Northern Territory and much of the Alice Springs District. Similar totals were recorded across much of the eastern half and southern border districts of New South Wales; most of Victoria, southern Tasmania, most of the eastern half of South Australia, and most of Queensland except the far northern Cape York Peninsula and areas of western Queensland.

Little or no rainfall was recorded in remaining parts of Western Australia, much of western South Australia, much of northern and central Tasmania, and scattered areas across the country.

Impact of recent rainfall on deficits

The Drought Statement, issued on 3 November 2017, discusses rainfall deficits over Australia for the 8-month (March 2017–October 2017) and 5-month (June 2017–October 2017) periods. The rainfall deficit map is available for this period as well as for standard periods.

The maps below show the percentage of mean rainfall that has been received for the rainfall deficit period for the 5- and 8-month periods ending 21 November 2017.

Rainfall for the period 1 March to 21 November 2017

Serious to severe rainfall deficiencies persist at the 8-month timescale along the west coast of Western Australia between about Exmouth and Perth, areas of coastal South Australia between the Nullarbor and Eyre Peninsula, East Gippsland in Victoria, and across the extreme east coast of Tasmania. Some isolated pockets of serious deficiencies persist in the Alice Springs District of the Northern Territory, southwestern to central Queensland, and western New South Wales. Rainfall during the past week has had little effect, except in a pocket inland of Carnarvon in Western Australia, where showers have reduced the severity of deficiencies somewhat.

The west coast of Western Australia has received up to 70% of average rainfall for the period, although an area around and inland of Exmouth has received less than 30% of average rainfall. Affected parts of South Australia have received between 40% and 70% of average rainfall, while far eastern Victoria and eastern Tasmania have received between 60% and 70% of average.

Rainfall for the period 1 June 2017 to 21 November 2017

Serious to severe deficiencies are present at the 5-month timescale across an area of southern Australia extending along the coast from the Eucla District in Western Australia, into the northern Eyre Peninsula and southern pastoral districts of South Australia, then across large areas of southern New South Wales, reaching north into the Central Tablelands and western slopes of the Great Dividing Range, and south into East Gippsland in Victoria.

Serious to severe rainfall deficiencies are also present along the east coast of Tasmania and in areas along the coast of Western Australia in the Gascoyne and Pilbara.

Rainfall in the last week has slightly eased deficiencies in affected areas of South Australia and the southeastern mainland, and in a pocket inland of Carnarvon in Western Australia.

Affected areas in southern Australia have generally received less than 60% of average rainfall for the period, although parts of eastern and southwestern New South Wales and southern pastoral areas of South Australia have observed lower totals, as low as 30% to 40% of average in part of South Australia north of Port Augusta. Totals are also similarly low right against the east coast of Tasmania.

In affected areas of the Gascoyne District in Western Australia, rainfall has generally been less than 60% of average, while some parts of the Pilbara have received less than 20% of average.

Map of rainfall totals for this week

Product code: IDCKGRWAR0