The Indian Ocean Dipole has switched to negative in recent days. This potentially means higher than average rainfall for south eastern Australia – if it persists. The most recent value of the Indian Ocean Dipole Index is -0.68, below the threshold for a negative event.
In a negative event, westerly winds intensify along the equator, allowing warmer waters to concentrate near Australia. This sets up a temperature difference across the tropical Indian Ocean, with warmer than normal water in the east and cooler than normal water in the west.
A negative IOD typically results in above-average winter–spring rainfall over parts of southern Australia as the warmer waters off northwest Australia provide more available moisture to weather systems crossing the country.
The most recent such event was in the winter and spring of 2016 and before that in the spring of 2010.