5 June
2006 - A study by the Australian Bureau of Meteorology
into historical rainfall across NSW has uncovered
a pattern of recurring extended dry and wet periods.
In particular, NSW endured a lower rainfall regime
from 1900 to 1946, with a statewide average annual
rainfall of 478 mm across these 47 years. A marked
shift occurred around 1947 to a higher rainfall
regime, which persisted through to around 2000.
Since 2000 a protracted dry and, on this occasion,
exceptionally warm period has set in over NSW
and in fact much of eastern Australia.
The Hon Greg Hunt MP, Parliamentary
Secretary with ministerial responsibility for
the Bureau of Meteorology, stated that the period
2001 to 2005 has been the driest five-year period
since 1968 and the warmest five-year period recorded
for NSW since 1910 when reliable temperature records
began over Australia.
The statewide average rainfall
for the past five years has been only 457.6 mm
compared with the standard reference period (1961-90)
average of 566.0 mm. The only five-year period
in the rainfall record (beginning in 1900) significantly
drier than the last five years was in the mid
1940s (439.1 mm in 1942-46). The current dry period
has also been accompanied by above average temperatures.
January 2001 to December 2005 is the warmest five-year
period in the statewide high-quality temperature
record, which is available from 1950. The average
maximum temperature for NSW was 1.2°C above
the average of 23.9°C.
Further evidence of the protracted
dry period has been the absence of extensive heavy
rain events during this period and, in particular,
of flooding across inland NSW which was a recurrent
feature during the years from 1950 to 2000 said
Mr Hunt. The last widespread flooding event across
inland NSW occurred in November 2000.
