Weekly Rainfall Update

For the week to 25 July 2017, rainfall was recorded across much of the South West Land Division of Western Australia; southeastern South Australia; Victoria; Tasmania; the Snowy Mountains in New South Wales, and in a small part of southeastern Queensland.

At the start of the week, a cold front extended over the Tasman Sea with a complex low pressure system to its west. Showers and thunderstorms produced light to moderate falls in Tasmania, most of Victoria, southeastern New South Wales and southeastern South Australia. A surface trough also produced thunderstorms and moderate falls in southeastern Queensland.  In the west, a deep low pressure system and associated cold fronts approached the southwest of Western Australia, producing an extensive cloudband, with moderate falls reported in the South West Land Division in Western Australia.

From the middle of the week, a cold front emanating from the same low pressure system tracked across southwest Western Australia, generating a westerly flow and mainly light falls. Another vigorous cold front and associated cloudband followed, producing further light to moderate falls in the southwest corner of Western Australia. The cold front continued its eastward track, weakening as it reached the southeast. Widespread light falls were recorded in western Tasmania, most of Victoria and southeastern South Australia.

Rainfall totals in excess of 100 mm were recorded in an area of southwest Western Australia, including the highest weekly total of 129 mm at Worsley Downs.

Rainfall totals between 50 mm and 100 mm were recorded across most of the Lower West and Central West districts in southwest Western Australia, the western half of Tasmania, and in small pockets of the Snowy Mountains in New South Wales and the Victorian Alps.

Rainfall totals between 10 mm and 50 mm were recorded in remaining areas of the South West Land Division in Western Australia; about the Mount Lofty Ranges, Mid North and South East districts of South Australia; in southwest, central and northeastern Victoria, as well as parts of East Gippsland; most of Tasmania except the northeast, and in southeastern Queensland.

Little or no rainfall was recorded in the Northern Territory, most of Queensland except the southeast corner, New South Wales away from the Snowy Mountains area, all of South Australia except in the southeast and remaining parts of Western Australia away from the southwest.

Impact of recent rainfall on deficits

The Drought Statement, issued on 3 July 2017, discusses rainfall deficits over Australia for the 4-month (March 2017–June 2017) period. 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 4-month period ending 25 July 2017.

Rainfall for the period 1 March 2017 to 25 July 2017

Serious or severe rainfall deficiencies are in place near the west coast of Western Australia, on the Eyre Peninsula in South Australia, and in western and southern Tasmania. Serious deficiencies are also present in South Australia on the Yorke and Fleurieu peninsulas, parts of the Adelaide region and the mid-North, and on Kangaroo Island; as well as in West Gippsland in Victoria.

Rainfall during the past week has slightly eased deficiencies in southwest Western Australia and in southwestern Tasmania, but little to no change in other affected areas. Rainfall received for the period in affected areas of Western Australia ranged from less than 20% of average near the Northwest Cape across the Gascoyne region to less than 60% of average in parts of South West Western Australia. Rainfall totals were less than 50% of average for much of the Eyre Peninsula in South Australia, and less than 70% of average for the majority of the other areas affected in South Australia, and less than 60% of average for West Gippsland. Rainfall totals were less than 80% for most of Tasmania.

Map of rainfall totals for this week

Product code: IDCKGRWAR0