Drought Statement - Issued 2nd November 2007


drought_text.html

For the 5 and 6-month periods ending 31st October 2007

Another dry month for central and south-eastern Australia

LINKS:
rainfall deficiencies definition
5-month rainfall deficiencies
6-month rainfall deficiencies

Short-term rainfall deficits remain over SA and southeastern parts of the country as a result of widespread below to very much below average October rainfall. Unless November is wetter than average, 2006-07 will be one of the very few instances in history where the Murray-Darling Basin (MDB) has suffered a winter-spring drought in successive years. The other years when this has occurred were 1918-19 (the latter was extremely dry), and 1940-41, with 1940 being very dry. In each of the years 1927, 1928, and 1929, large parts of the MDB had a winter-spring rainfall total in decile 3 or lower, although individually none of the years was extremely dry.
See October rainfall pattern

Since the start of winter, South Australia has been the worst hit state, with the five-month average being the second lowest on record at just 36 mm. At the yearly time-scale (not shown), rainfall deficiencies have weakened somewhat compared with the situation at the end of September as October 2007 has generally had higher rainfall totals than October 2006.

For the 5-month period from June to October 2007, an area of serious to severe rainfall deficiencies covered most of SA, southwest Queensland, western NSW, northern Victoria, regions in the southern NT, scattered parts of WA and an area in northeastern Tasmania. Large areas of lowest on record covered South Australia and southwestern Queensland into southeastern NT.

Rainfall deficiencies for the 6-month period from May to October 2007 were widespread across the southern half of Western Australia as May rainfall was also below average in this region. SA was also affected, but to a much lesser extent than for the five-month period. There were small areas of lowest on record in these areas.

The deficiencies discussed above have occurred against a backdrop of multi-year 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 MDB 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.

Rainfall deficiency maps for standard periods out to three years are available.


Note: The terms used to describe rainfall in these Drought Statements have the following meanings -

Serious deficiency - rainfalls in the lowest 10% of historical totals, but not in the lowest 5%
Severe deficiency - rainfalls in the lowest 5% of historical totals
Lowest on record - lowest since at least 1900 when the data analysed begin

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


For more information regarding this rainfall deficiencies statement, please contact the following climate meteorologists in the National Climate Centre:

Blair Trewin on (03) 9669 4623
Andrew Watkins on (03) 9669 4360
Grant Beard on (03) 9669 4527

External Sites Relating to Drought

The Bureau of Meteorology does not make formal drought declarations as these are done by either the relevant State Governments or by the Australian Government. The Australian Government Program is called Exceptional Circumstances and it is administered by the Federal Department of Agriculture, Fisheries and Forestry (DAFF). General information about Australian Government drought assistance is available at http://www.daff.gov.au/droughtassist.



Click on the map for full resolution.
Click on the map for full resolution.
A black and white version is also available.

Click on the map for full resolution.
Click on the map for full resolution.
A black and white version is also available.