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For the 3 and 12-month periods ending 31st May 2008
A dry autumn over much of Australia
LINKS:
rainfall deficiencies definition
3-month rainfall deficiencies
12-month rainfall deficiencies
May 2008 was Australia’s
driest May on record. The dry May combined
with relatively poor rainfall in March and April contributed to large
parts of Australia experiencing rainfall deficiencies during autumn.
Deficiencies at the yearly timescale highlight areas that have received
little rainfall relief in recent months, with large areas of deficiencies
through central and southern parts of Australia.
For the 3-month period from March 2008 to May 2008,
areas of serious to severe rainfall deficiencies covered large parts of
Australia. In northern Australia this was indicative
of an early end to the wet season, whilst southern Australia experienced a
poor start to the southern wet season. Across the Murray-Darling Basin it
was the fourth driest autumn on record.
Rainfall deficiencies for the 12-month period from June 2007
to May 2008 are evident over much of SA and southern NT and also in parts of
southern WA, western Queensland and NSW, western and central Victoria and
northern and eastern Tasmania. Over the 12-month period, much of eastern
Australia had some benefit from above average rainfall associated with the
2007/08 La Niña event. In contrast, central areas of Australia have seen typically
below average falls in recent months, with record-low falls evident for the
period over a large area in southeastern parts of the NT and in small patches
in central SA.
In some parts of southern Queensland and northeastern NSW, rainfall since
the start of June has been sufficient to ease or remove the 3-month deficits.
For areas covered by deficiencies over a 12-month period, average to above
average winter falls are needed to ease deficiencies.
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. The combination of record heat and widespread
drought during the past five to ten years over large parts of southern and eastern
Australia is without historical precedent and is, at least partly, a result of climate
change.
For more information go to a
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
Blair Trewin on (03) 9669 4623
Lyn Bettio on (03) 9669 4165
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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