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For the 7 and 24-month periods ending 31st December 2007
Short-term deficiencies ease, long-term deficiencies remain
LINKS:
rainfall deficiencies definition
7-month rainfall deficiencies
24-month rainfall deficiencies
An established La Niña event contributed to above average December rainfall across
much of the country, especially in the east, which eased short-term rainfall
deficiencies in many areas. Whilst some deficiencies still remain, especially
in South Australia and Western Australia, these are not as extensive or severe
as they were at the end of November. Short-term deficiencies have eased in eastern
Australia, excluding Tasmania, but long-term deficiencies remain, especially in
Tasmania, southeast Queensland, the southwest coast of WA and central Victoria
into southern NSW.
See December
rainfall pattern
For the 7-month period from June to December 2007 areas of serious
to severe rainfall deficiencies covered parts of central and northeast SA, together
with a small area in the southern NT, scattered parts of WA, western NSW and an area
in eastern Tasmania. However, when compared to the end of November, the total area
of severe deficiencies and lowest on record falls has greatly decreased, especially
in SA, with only central SA showing small areas of lowest on record. Above to very
much above average December rainfall also resulted in the easing or removal of deficits
across large parts of western Victoria, WA and southwestern NSW in comparison with the
situation at the end of November.
Rainfall deficiencies for the 24-month period from January 2006 to
December 2007 were widespread across the southeastern corner and southwestern coastal
parts of the continent. Southeastern Queensland and northcentral and southeastern SA
were also affected. There were areas of lowest on record in WA from north of Perth
to Carnarvon and in a large band from the east of Melbourne to the south of Canberra.
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 twelve months to elevate totals since January 2006 out of the lowest decile.
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 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
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:
Grant Beard on (03) 9669 4527
Lyn Bettio on (03) 9669 4165
David Jones on (03) 9669 4085
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.
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