Issued 5 February 2008
Long-term deficiencies remain in southern and eastern Australia
A La Niña event contributed to above average January rainfall across eastern
Australia, excluding Tasmania and southern Victoria. However, long-term deficiencies
still remain, especially in Tasmania, southeast Queensland, the west coast of WA and
central Victoria into southern NSW. Short-term deficiencies remain in parts of southern
Australia, excluding Victoria, and have increased slightly in South Australia and
the southern NT.
See January rainfall pattern
8-month rainfall deficiencies
For the 8-month period from June 2007 to January 2008, areas of serious to severe rainfall deficiencies covered parts of central and northeast SA, together with southeastern NT, scattered parts of WA, isolated areas of western NSW and an area in eastern Tasmania. When compared to the situation at the end of December, average to below average January rainfall across the western two thirds of the country and Tasmania has increased the total area of severe deficiencies in SA and southern NT, with central SA also showing an increased area of lowest on record.
24-month rainfall deficiencies
Rainfall deficiencies for the 24-month period from February 2006 to January 2008 were widespread across the southeastern corner and west coast parts of the continent. Southeastern Queensland and north-central and southeastern SA were also affected. There were areas of lowest on record in WA from north of Perth to Shark Bay, in eastern Tasmania and in a large band from the east of Melbourne to the ACT. Above average rainfall along much of eastern Australia in January has slightly reduced the extent of severe deficiencies in southeast Queensland. However, average to below average rainfall elsewhere has led to an increase in severe deficiencies in southern SA and western WA.
The worst of the long-term deficiencies are likely to remain for some time. For example, above average (decile 8-9) rainfall is needed in the rainfall deficient areas over the next six months to elevate totals since February 2006 out of the lowest decile.
The deficiencies discussed above have occurred against a backdrop of decade-long rainfall deficits and record high temperatures that have severely stressed water supplies in the east and southwest of the country. Several years of above average rainfall are required to remove the very long-term deficits. Furthermore, the combination of heat and drought during the past five to ten years over the Murray Darling Basin and southeastern Australia is outside the typical range of variability experienced during the previous 100 years. For more information go to a recent Special Climate Statement on the six years of widespread drought in southern and eastern Australia, November 2001 to October 2007
Lowest on record - lowest in the historical analysis, which runs from 1900.
Severe deficiency - rainfalls in the lowest 5% of historical totals.
Serious deficiency - rainfalls in the lowest 10% of historical totals, but not in the lowest 5%.
Very much below average - rainfalls in the lowest 10% of historical totals.
Below average - rainfalls in the lowest 30% of historical totals, but not in the lowest 10%.
Average - rainfalls in the middle 40% of historical totals.
Above average - rainfalls in the highest 30% of historical totals, but not in the highest 10%.
Very much above average - rainfalls in the highest 10% of historical totals.
Product Code IDCKGD0AR0