Friday, June 27, 2008

{News} 080627 Rain outlook bleak for winter months

Rain outlook bleak for winter months

EUGENE DUFFY
Fairfax Media, 27/06/2008 8:49:00 AM

BENDIGO has received only 60 per cent of its average rainfall for the first half of the year and the outlook is bleak. But the prospects of a wet winter after a dry autumn are diminishing with the latest Bureau of Meteorology rainfall outlook predicting only a 35 to 40 per cent chance of average rainfall over the nest three months.
The six-month total of 128mm of rain - the second lowest in the past 16 years - is a bad start to the year where inflows into the Murray River systems, including the Campaspe, Loddon and Coliban catchments are again under pressure.
Coliban Water continues to use water from the Goulburn system and the Superpipe to supply Bendigo, enabling reserves at the Lauriston Reservoir to remain about 40 per cent and its overall storages at 13.4 per cent more than twice last year’s level.
But good above average rains in May and July last year helped build these water reserves, a situation the bureau outlook indicates is less probable for the remainder of winter 2008.
Bureau of Meteorology senior climatologist Andrew Watkins said the outlook was showing strong indicators for both a drier and warmer than average winter and early spring.
Dr Watkins said while Pacific Ocean temperature patterns, which influence La Nina and El Nino events remained neutral, the outlook was being driven in part by temperature anomalies in the Indian Ocean.
He said cooler than average ocean temperatures south of Indonesia and warmer temperatures elsewhere in the ocean were affecting moist rain-laden north-west cloud bands that would normally bring rain through autumn and winter.
"That change in the Indian Ocean means it is harder for these systems to form," he said.
"We are seeing a pattern with stronger signals for this time of year and while we are not quite seeing a positive Indian Ocean Dipole, some models lean towards that."
But he said this phenomenon did not explain other factors affecting rainfall including a tendency for western winds and cold fronts to slide further south and miss the Australian mainland. In addition the frequency of La Nina events over the past 10 years was another factor influencing Australian rainfall.
"So in a sense we are getting hit by this triple whammy,"
Dr Watkins said He said the real impact of climate change on rainfall was being felt not in single extreme years, but in consecutive below-average rainfall years.
The Bureau of Meteorology is teaming with CSIRO and federal and state governments on a three-year $7 million climate investigation into factors such as the loss of ozone over Antarctica and how these complex factors contribute to denude the Murray Darling Basin of rainfall.

Source: http://bendigo.yourguide.com.au/news/local/news/business/rain-outlook-bleak-for-winter-months/798704.aspx

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