The Bureau of Meteorology has confirmed that a negative Indian Ocean Dipole (IOD) is underway, increasing the likelihood of above average winter-spring rainfall for much of southern and eastern Australia.

“Most climate models surveyed by the bureau predict a negative IOD pattern is likely to persist until at least mid-spring,” the latest climate driver update says.

The IOD Index, which reflects differences in sea surface temperatures between the eastern and western tropical Indian Ocean, has been below the IOD threshold for eight of the past nine weeks, reaching the point at which an event is declared.

In the Pacific Ocean, three of seven models surveyed by the bureau indicate cooling temperatures will be enough to reach La Nina thresholds in the spring, with the remaining four models staying neutral.

“This forecast cooling may also be contributing to the outlook for above median rainfall for much of Australia in the coming months,” the bureau says.

The climate driver update could indicate an increased risk of heavy rain, flooding and thunderstorms, while there could also be a reduced risk of early season bushfires for eastern and south-east mainland Australia.