An El Nino event remains likely for Australia but the weather bureau has stopped short of declaring it will definitely happen.
The Bureau of Meteorology on Tuesday released its latest climate driver update, stating an El Nino development is “considered likely” in the coming weeks.
But the forecast will remain at an alert stage until the next update on August 15.
“When we go to an alert historically, an El Nino event does develop about 70 per cent of the time,” the bureau’s national climate services manager Karl Braganza told reporters.
An El Nino event increases the risk of drought, heatwaves and bushfires.
Sea surface temperatures in the tropical Pacific Ocean are exceeding the thresholds needed for an El Nino event, but the atmosphere patterns are pointing toward more neutral conditions.
“The atmosphere hasn’t quite coupled or reinforced the pattern that we see in the ocean that’s typical of an El Nino event,” Dr Braganza said.
“We’ll wait for conditions to lock in before we declare an event.”
Hot global temperatures are keeping all of the oceans warmer than expected, which could be affecting the atmospheric response to El Nino.
“Historically, we haven’t seen situation like this before where we’re going into an El Nino event with record global ocean temperatures,” Dr Braganza said.
Antarctic sea ice was also at the lowest levels ever recorded in August, with a chunk of ice the size of Western Australia missing.
That would be having a notable impact on the Southern Hemisphere’s climate system, Dr Braganza said.
Climate modelling suggests surface temperatures in the Indian Ocean will change in late winter or early spring, bringing less rainfall and exacerbating the drying influence from El Nino.
The bureau is continuing to forecast warmer and drier conditions across the country between August and October.
Tara Cosoleto
(Australian Associated Press)