Rainfall Update

For the week to 23 January 2018, rainfall was recorded across northern Australia, and in the western half of Western Australia.

At the start of the week, a surface trough near coastal Western Australia, which connected to low pressure systems over inland Pilbara and in the southwest, generated showers and thunderstorms in the western parts of the State. Mostly moderate rainfall totals were reported throughout the week in the Pilbara, Gascoyne and Goldfields districts, and the South West Land Division in Western Australia as the surface trough persisted in the west.

During the week, the monsoon trough aligned with the northwest coast of Western Australia, extending across the Top End of the Northern Territory to the Gulf of Carpentaria. Thunderstorms and showers developed near and along the monsoon trough throughout the week, and produced moderate to heavy falls in the Kimberley in Western Australia, the Top End and central parts of the Northern Territory, the Gulf Country and the Cape York Peninsula.

At the end of the week, light falls from isolated showers were recorded in small parts of southeastern Australia as a low pressure trough extended from central to southeast Australia. In the north, a weak tropical low pressure system developed over the Carpentaria District in the Northern Territory, produced locally heavy falls in the western Gulf Country.

Rainfall totals exceeding 100 mm were recorded about the Kimberley coast, across much of the northern Top End of the Northern Territory and Gulf Country, and the Cape York Peninsula in Queensland. Some areas about the north and east coasts reported rainfall totals in excess of 300 mm, including the highest weekly total of 630 mm at Bing Bong Port in the Northern Territory.

Rainfall totals between 50 mm and 100 mm were recorded in the southern tropics of north Queensland; the southern Top End of the Northern Territory; the western Kimberley; and western parts of the Pilbara and Goldfields districts in Western Australia.

Rainfall totals between 10 mm and 50 mm were recorded across remaining areas of the western half of Western Australia, through the central interior of the Northern Territory and areas of northwestern Queensland.

Little or no rainfall was recorded across remaining parts of Australia away from the western half of Western Australia, and away from northern Australia.

Impact of recent rainfall on deficits

The Drought Statement, issued on 9 January 2018, discusses rainfall deficits over Australia for the 7-month (June 2017–December 2017) and 10-month (March 2017–December 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 7- and 10-month periods ending 23 January 2018.

Rainfall for the period 1 June 2017 to 23 January 2018

Serious to severe deficiencies persist at the 7-month period in areas of the western to central Pilbara in Western Australia. Deficiencies are also evident in central eastern New South Wales and along the east coast of Tasmania; and in scattered locations across the south of Western Australia and near Port Augusta in South Australia, far eastern Victoria, and central to western Queensland.

Rainfall in the last week has slightly eased deficiencies in the eastern Pilbara.

Affected areas in Western Australia have received less than 40% to 50% of the average for the period, with some parts having now received at least average rainfall for the period. Remaining affected areas have generally received between 40% and 60% of average.

Rainfall for the period 1 March to 23 January 2018

Serious to severe rainfall deficiencies persist at the 10-month period persist along the west coast of Western Australia between about Exmouth and north of Perth, extending inland east to parts of the South West Land Division and southwest of the Goldfields District. Deficiencies are also present in scattered parts of western and central Queensland, and near Ceduna in South Australia.

Rainfall in the last week has eased deficiencies slightly in the Pilbara and areas along the west coast, south of the Gascoyne. Affected areas have received less than 50% to 70% of the average for the period, with some affected areas in Western Australia now receiving average rainfall for the period.

Affected areas in far western Queensland received less than 30% of the average, while areas in central Queensland have received between 30% and 50% of the average for the period.  Affected areas in South Australia, eastern Victoria and Tasmania received less than 70% to 80% of the average for the period.