* Tropical Pacific Ocean temperatures cool in last fortnight
* Drier spring weather for Australia still likely - weather bureau (Adds detail, quote)
By Colin Packham
SYDNEY, Sept 25 (Reuters) - Tropical Pacific Ocean temperatures indicating the onset of an El Nino have eased over the last two weeks, reducing the chance of the weather event emerging, the Australian Bureau of Meteorology said on Tuesday.
However, the bureau warned the risk of an El Nino -- which can trigger drought in Australia, Southeast Asia and India and floods in parts of South and North America -- returning remained.
Pacific Ocean temperatures had cooled in the last fortnight, while other indicators remained in neutral territory, it said.
The bureau said that despite the change in indicators conditions continued to favour below average rainfall over much of Australia in the southern hemisphere spring.
"We are seeing the Indian Ocean showing a pattern that would bring drier conditions to at least central and south east Australia," Andrew Watkins, manager of climate prediction at the weather bureau's National Climate Centre said.
"That signal is a little stronger than the El Nino signature in the Pacific is showing."
Japan's weather bureau said on Sept. 10 its climate models indicated the El Nino phenomenon was under way and there was a high chance it would last until winter.
El Nino can cause above average rains in northern Peru and Bolivia, drought in Southeast Asia, Australia, India and northeast Brazil, cyclones in the central Pacific and stormy weather in the southern and western United States.
The worst El Nino on record in 1997/98 killed more than 2,000 people and caused property damage estimated at $33 billion. The pattern can also cause serious damage to crops such as wheat in Australia due to drought. (Reporting by Colin Packham; Editing by Ed Davies)