Issued on 5 August 2013
Rainfall deficiencies ease in the southeast but continue in Queensland
July rainfall was average to above average across most of southern Australia, with the exception of the far west coast and east coast where rainfall was in the lowest 10% of records for East Gippsland. Particularly goods falls were seen in parts of Tasmania and southern parts of South Australia (and in the highest 10% of records for most of the West Coast district). Further north, rainfall was mostly low, but near-average owing to seasonally low rainfall at this time of year. Below-average rainfall along the Western Australia coast means that short term (3 to 6 month) rainfall deficiencies have developed in some areas.
10-month rainfall deficiencies
Rainfall deficits for the 10-month (October 2012 to July 2013) period have seen improvement across Victoria, Tasmania and southern Queensland following recent rainfall. Much of western Victoria and Tasmania have been lifted from severe to serious deficiencies (improving from totals in the lowest 5% of records, to totals in the lowest 10% of records) with deficiencies cleared from most of northeastern Tasmania and lower southeastern South Australia. Serious to severe deficiencies remain across much of Queensland west of the coastal ranges (although the Channel Country is free of deficits) and in a small area of the Nullarbor Plain, and have emerged in a small area north of Carnarvon in Western Australia. Rainfall percentages for the 10-month period show much of western Queensland and northeastern South Australia has received less than 60% of the long-term average rainfall.
16-month rainfall deficiencies
Longer-term rainfall deficiencies for the 16-month (April 2012 to July 2013) period have also seen improvement across the southeast mainland and Tasmania. Serious deficiencies remain across most of northern and northwest Victoria and adjacent parts of New South Wales, in areas between northeastern South Australia and Queensland's Gulf Country (slightly expanding in the Channel Country), and between Charleville (southern Queensland) and Bourke (northern New South Wales). Deficiencies persist on the Nullarbor Plain, although the area of lowest-on-record rainfall has decreased for the 16-month period compared to the previous 15-month period. Deficiencies also remain along the Western Australian coast south of Shark Bay, and have worsened and increased in extent compared to the previous drought period. The rainfall percentages map shows areas having received less than 60% of long-term average rainfall for the period are focused on eastern central Australia, parts of the inland of the eastern States and the Nullarbor Plain.
Weekly soil moisture totals in the upper soil layer have generally increased across southern Queensland compared to the weekly values one month ago. Values across southern Queensland are above average but remain below average across parts of the remainder of Queensland and the north of the Northern Territory. Soil moisture values also increased across the southeast and are now above average in inland New South Wales, the southern half of South Australia, western Victoria, and coastal Western Australia east of Bremer Bay. Soil moisture has risen across Tasmania and Victoria but is still below average in parts of the southeastern half of Victoria and northern and central Tasmania. A large area along the coast of Western Australia, south of the Northwest Cape, has below-average soil moisture but most of the southwest has returned to near-average.
For the deeper layer, soil moisture generally shows a similar pattern to that of last month. Values across southern South Australia have increased (majority above to very much above average); eastern Tasmania and the majority of Victoria (except in the east) remain below average, but generally less so than last month; Western Australia between Shark Bay, Kalgoorlie-Boulder and the southwest is further below average than last month. Soil moisture across the Top End and tip of the Cape York Peninsula remains below average. Soil moisture remains above average across northwest and central Western Australia, inland New South Wales, southwestern Queensland and along the east coast between Tweed Heads and Townsville.