The La Nina weather pattern responsible for much of the increased rainfall in eastern Australia over the past two years is over, according to the Bureau of Meteorology.

It says La Nina conditions are no longer present in either the Pacific Ocean or the atmosphere, and conditions have returned to neutral.

“The 2011/12 La Nina began last spring, and played a key role in prolonged wet conditions for eastern Australian throughout summer and into early autumn,” the bureau says.

This resulted in southeast Australia recording its wettest seven-day period in history, while the combined effect of two back-to-back La Nina events over 2010/11 and 2011/12 contributed to Australia's wettest two-year period on record.

The bureau’s Manager of Climate Prediction Services, Andrew Watkins, says the tropical wet season will still continue until the end of April with the possibility of tropical cyclones and further heavy rain.

But he says the likelihood of a third successive La Nina year is low, at around 30%.  

“The likelihood of a third successive La Nina remains low, with none of the models used by the bureau indicating a return. Approximately 70% of La Nina events that have returned for a second year are followed by neutral or El Nino conditions.”

Meanwhile, the United Nations Intergovernmental Panel on Climate Change has issued a new report forecasting stronger tropical cyclones and more frequent heatwaves, deluges and droughts.

The panel of climate scientists is warning nations to prepare for the impact of global warming-fuelled climate change with the highly populated poor regions of the world at greatest danger.

It blames the scale of recent and future disasters on a combination of man-made climate change, population shifts and poverty.

The UN scientists have identified Mumbai, Miami, Shanghai, Bangkok, Guangzhou, Ho Chi Minh City, Rangoon and Kolkata, as well as low lying islands such as the Maldives, as being at particular risk of floods, storms and rising seas.