An El Nino and a positive Indian Ocean Dipole (IOD) are underway, reinforcing the outlook for warmer and drier conditions for much of Australia over the next three months, the Bureau of Meteorology said today.

The bureau moved to an El Nino Alert in early June, indicating a 70% chance of the climate driver developing this year, but had held off from declaring an event until oceanic and atmospheric indicators reached key thresholds.

Today’s update says ocean indicators “firmly exhibit” an El Nino state and there are signs the atmosphere is responding to the pattern of sea surface temperatures in the tropical Pacific.

“This coupling is a characteristic of an El Nino event and is what strengthens and sustains an event for an extended period,” the bureau said. “Climate models indicate this El Nino is likely to persist until at least the end of February.” 

The bureau also says an Indian Ocean index has held above a positive threshold for a fifth week, indicating a positive IOD is underway. Models suggest it will persist until the end of spring.

“When a positive IOD and El Nino occur together, their drying effect is typically stronger and more widespread across Australia,” the climate driver update says.

Australia has already experienced warm winter conditions, which have continued into spring, raising concerns over increasing bushfire risks over coming months.

The bureau today warned of strong winds and elevated fire danger in Australia’s southeast ahead of an approaching cold front.

Maximum temperatures were sitting 10-15 degrees above the September average through large parts of NSW and eastern Victoria, with Sydney’s Observatory Hill reaching 34.6 degrees at 1:55pm.

The Rural Fire Service issued Total Fire Bans for the greater Sydney area and the Far South Coast, where the fire danger rating was upgraded to catastrophic as a result of high temperatures and the forecasts for hot, dry winds.

The bureau’s long-range forecast for Australia indicates warmer and drier than average conditions are likely across most of southern and eastern Australia from October to December.

For winter, the national mean temperature was 1.53 degrees Celsius above the 1961–1990 average and the warmest on record since national observations began in 1910.

Queensland, NSW and Tasmania experienced the warmest winter on record, while it was the second warmest in Victoria and SA.