In the past, this pattern had often, but not always, had been associated with above average rainfall in eastern and northern Australia, it said.

The national climate centre said this while reporting a mixed autumn rainfall outlook for Australia in the period March to May.

The chances of above average seasonal rainfall ranged from more than 75 percent in north Queensland to less than 30 percent in the southwest of Western Australia, it said.

For much of New South Wales (NSW), the chances of above average rainfall were near 70 percent, implying a 30 percent chance of below average falls, it said.

However, the skill of ther outlook system was low across NSW for this period, leading forecasters to reduced confidence in the estimates, it said, adding that probabilities should be treated with caution.

The outlook uses data from both the Pacific and Indian Oceans.

The Indian Ocean was much warmer than normal close to Australia and was the main cause of latest probabilities, the climate centre said.

The January southern oscillation index (SOI) was plus 5.1, somewhat lower than the 13 recorded in December.

Sustained high positive SOI values indicate the presence of the La Nina weather pattern.

Rainfall has been above average across much of Australia for the past six months, consistent with a maturing La Nina pattern, the centre said.