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For the 6 and 24-month periods ending 31st March 2008
Short-term rainfall deficiencies expand in central Australia
LINKS:
rainfall deficiencies definition
6-month rainfall deficiencies
24-month rainfall deficiencies
Short-term rainfall deficiencies expanded and intensified in central
Australia as a result of below average March rainfall. In addition,
continued higher than average temperatures exacerbated the effects of
these rainfall deficits. In parts of eastern and southern Australia, there
was a slight easing of rainfall deficiencies at the two-year timescale,
although the overall pattern remains the same.
See March
rainfall pattern
For the 6-month period from October 2007 to March 2008,
an area of serious to severe rainfall deficiencies covered much of the
southern half the Northern Territory and some adjacent areas in far western
Queensland. There were also some smaller patches near Marree in South
Australia with serious to severe deficiencies. Maximum temperatures of one
to two degrees above average have worsened the dry conditions.
Rainfall deficiencies for the 24-month period from April
2006 to March 2008 were analysed in southwest WA, Tasmania, southeast
Queensland, northern SA and in a band stretching from the Bight coast of
SA across much of Victoria and the western slopes and plains of southern
NSW. The pattern is very similar to that observed at the end of February,
but as March 2008 was wetter than March 2006 in most areas, there was some
easing of these two-year deficits. One exception was the Eyre Peninsula and
Bight coast of SA which was drier this year so the 24-month deficits
intensified. Record-low falls were evident in western WA, on the Eyre
Peninsula in SA, near Melbourne and in eastern and northern Tasmania.
The worst of the long-term deficiencies are likely to remain for some time.
For example, above to very much average rainfall (deciles 8-10) is
needed in the rainfall deficient areas over the next six months just to
elevate totals since April 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
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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