Weekly Rainfall Update
For the week to 4 August, rainfall was recorded in the South West Land Division in Western Australia, southern and eastern Victoria, western Tasmania, parts of the east coast of New South Wales and about the north tropical coast and far northern Cape York Peninsula. Little or no rainfall was recorded elsewhere.
At the start of the week, a low pressure system and surface trough slowly moved off the New South Wales coast, and widespread showers eased and contracted to the central to southeast coast of New South Wales, and light to moderate falls were recorded in parts of eastern Victoria.
In the south, a cold front embedded in a westerly airstream tracked over Tasmania, generating moderate falls in western Tasmania. A large high pressure system dominated much of the Australian continent in the middle of the week, with only a few coastal showers reported.
In the second part of the week, the high pressure system was located over the Tasman Sea, and extended a firm ridge along the east coast of Australia. Moist onshore flow produced showers and moderate falls in the north tropical coast and far northern Cape York Peninsula.
A cold front and trough tracked over far southeast Australia, and generated light to moderate falls over western Tasmania, and light falls across that state's north. A complex area of low pressure and cold front followed and tracked over western Tasmania and southern Victoria. Light to moderate falls were recorded in western Tasmania and along the south coast of Victoria.
At the end of the week, in the west, a low pressure system, cold front and pre-frontal trough moved over southwest and southern Western Australia. Widespread moderate falls were reported over large areas of the South West Land Division, with locally heavier falls reported in the South Coastal and South East Coastal districts in Western Australia.
Rainfall totals in excess of 100 mm were recorded along parts of the South Coastal District in Western Australia, including the highest weekly total of 122 mm at King River.
Rainfall totals in excess of 50 mm were recorded in the South Coastal and South East Coastal districts of Western Australia, an area in western Tasmania and the north tropical coast of Queensland.
Rainfall totals between 10 mm and 50 mm were recorded across large areas of the South West Land Division in Western Australia, western Tasmania, parts of southern and eastern Victoria, pockets of the Hunter District in New South Wales, and in the north tropical coast and far northern Cape York Peninsula of Queensland.
Rainfall totals of less than 10 mm were recorded across remaining parts of the South West Land Division in Western Australia, the eastern half of Tasmania, parts of eastern Victoria and east coast New South Wales, and in the far northeast coast of Queensland.
Impact of recent rainfall on deficits
Rainfall deficits over Australia for the 4-month (April–July 2020) and the 28-month (April 2018–July 2020) periods are discussed in the Drought Statement, to be issued on 6 August 2020.
Rainfall deficit maps are available for these periods 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 4-month and 28-month periods, extended to the week ending 4 August 2020.
Rainfall for the period 1 April to 4 August 2020
Serious or severe rainfall deficiencies for the 4-month period are in place in Western Australia across most of the southwestern half of the State. Serious rainfall deficiencies are also in place across parts of central southern and southeast Queensland. Other small areas experiencing serious rainfall deficiencies include the extreme south coast of New South Wales, the southwest of the Alice Springs District in the Northern Territory, and pockets of southwest and northern South Australia.
Inland areas of Western Australia, southwest South Australia and parts of central Queensland received less than 40% their average for the period, while remaining areas have generally received less than 80 % to 40% of their average for the period.
Rainfall for the period 1 April 2018 to 4 August 2020
Serious to severe rainfall deficiencies are in place for the 27-month period across the South West Land Division, much of the west of the Gascoyne and Pilbara, along the south coast of Western Australia, the northern tip of the Kimberley, the east of the Interior District, and pockets throughout the inland areas of the State. Deficiencies are also in place across much of the Northern Territory, nearly all of South Australia, the southeastern quarter of Queensland, much of western and northern inland parts of New South Wales, and across eastern Victoria and the northern border regions of that state.
Affected areas through the interior of Australia into western New South Wales, southern inland Queensland, northeastern South Australia and the southern parts of the Northern Territory have generally received less than 50% of average rainfall for this period. Remaining areas have generally received between 80% and 50% of average rainfall.
Product code: IDCKGRWAR0