Neutral conditions are continuing in the Indian and Pacific oceans as climate driver measures are monitored for thresholds associated with wet weather, a Bureau of Meteorology update shows.

All models indicate the Indian Ocean Dipole (IOD) index will meet or exceed negative thresholds this month, before returning to neutral values in December. To be classified as a negative event, values would need to be sustained below the threshold for at least six to eight weeks.

A negative IOD reflects warmer than average sea surface temperatures near Australia, which can provide more moisture for frontal systems and lows crossing the country.

In the Pacific, the bureau’s models suggest sea surface temperatures are likely to remain within the El Nino Southern Oscillation neutral range.

Of six other models surveyed, only one suggests temperatures in the tropical Pacific are likely to touch or exceed the La Nina threshold from this month to February, and one shows the threshold will be exceeded but only for December and January.

If a La Nina does develop in coming months, it is expected to be relatively weak and short-lived.

La Nina conditions have historically resulted in above average rainfall over much of Australia through winter, spring and early summer.

The bureau says global sea surface temperatures since July have been just short of the all-time highs recorded last year. They remain above all other years since observations began in 1854.

“The sustained nature of this significant global ocean heat suggests that climate indicators such as ENSO and IOD may not behave or evolve as they have in the past,” it says.