By Colin Packham
SYDNEY (Reuters) - Surface temperatures of the equatorial Pacific Ocean have exceeded El Nino thresholds for several weeks and there is a greater than 70 percent chance of the weather pattern emerging, the Australian Bureau of Meteorology (BOM) said on Tuesday.
The BOM had earlier projected at least a 70 percent chance of El Nino arriving by February 2015. The weather event occurs every four to 12 years and can trigger drought in some parts of the world while causing flooding in others.
"Typically, after the ocean has exceeded thresholds for an extended period, an El Nino is considered to be underway," the BOM said in a statement.
However, the BOM said trade winds, cloudiness and tropical rainfall, have not shown sustained and widespread patterns consistent with the weather event linked to hot, dry weather.
Japan last week declared an El Nino, marking the first declaration by a major meteorological bureau of the much-feared weather phenomenon, which had been widely expected to emerge this year.
(Editing by Himani Sarkar)