Pacific Ocean temps exceed El Nino levels: Australia

Reuters 14 Oct 09;

SYDNEY (Reuters) - Central and eastern Pacific Ocean temperatures are exceeding El Nino levels and will remain at levels typical of an El Nino weather event until early 2010, Australia's Bureau of Meteorology said on Wednesday.

"The tropical Pacific Ocean sea surface remains warmer than average and exceeds El Nino thresholds in central to eastern regions," said the bureau in its fortnightly ENSO El Nino report.

"While such conditions are fairly typical during an El Nino event, values of the Southern Oscillation Index and tropical cloud patterns remain inconsistent with normal El Nino conditions," said the bureau.

"Despite this, rainfall patterns over eastern Australia for the past three months are broadly in keeping with the impact of an El Nino event."

The Southern Oscillation Index (SOI), a major indicator of a drought-bringing El Nino weather pattern, stood at plus one for the 30 days to October 10, from plus three previously, the bureau said on Tuesday.

A consistently negative SOI points to the development of an El Nino. The SOI measures the pressure difference between the Pacific island of Tahiti and the Australian city of Darwin.

The bureau also said on Tuesday that recent trends showed some weakening of the El Nino signal and that its impacts are likely to be more variable than past El Nino events.

For the bureau's report see: www.bom.gov.au/climate/enso/

(Reporting by Michael Perry; Editing by Mark Bendeich)