The Bureau of Meteorology (BOM) has upgraded the chances of a third consecutive La Nina climate event forming in the Pacific Ocean but has stopped short of officially calling it as yet.
This week the BOM took its La Nina ratings from 'La Nina watch' to 'La Nina alert', meaning the chances of La Nina forming are now three times more likely than normal, with the BOM saying a La Nina was a 70 per cent chance of forming.
With La Nina events strongly correlated with above average rainfall through eastern Australia and a Indian Ocean Dipole (IOD) negative event, also linked with above average rainfall, in place on the other side of the country the BOM says there is a very high chance of wet conditions over eastern Australian in coming months.
Warmer than average sea water around Australia is likely spur more moisture into the atmosphere which in turn will mean more rain.
The IOD negative event continues.
The IOD index has been very close to or within negative IOD thresholds (i.e. at or below 0.4 °C) since early June, with the latest weekly value one of the strongest observed so far during this event. All surveyed climate models indicate that negative IOD conditions are likely to continue into late spring.
There have been healthy late winter rain across many parts of Australia through August, with flooding experienced in Gippsland and large tracts of Western Australia receiving some of the heaviest single day August rainfall figures on record, with over 60mm in semi-arid areas to the north of Geraldton.
Further falls are expected over southern Australia over the next seven days.