Upcoming El Nino shaping to be ‘strongest ever’

The El Nino climate event declared by the Bureau of Meteorology this week is likely to be one of the strongest ever, say weather experts.

The bureau yesterday confirmed the major meteorological driver - which typically brings warmer and drier conditions - was underway in the tropical Pacific.

Current forecasts are predicting El Nino will strengthen through the southern hemisphere winter and spring and challenge records, according to weather channel Weatherzone.

“This El Nino is expected to become a strong or very strong event, with the bureau pointing out that “around half of the models indicate this event could peak at levels among the highest observed since 1950.”

One of the key benchmarks used to measure El Nino is the relative Niño3.4 index – a measure of sea surface temperature anomalies on the central tropical Pacific Ocean.

In Australia, El Nino happens when the relative index is above +0.8 degrees for an extended period.

Bureau of Meteorology forecast shows the current Niño3.4 index will hit +3.3 degrees this November, a mark that would smash the existing record by 0.5 degrees.

While El Nino does not guarantee drought or extreme weather, the disruptive weather pattern can increase the odds of those conditions.

The bureau’s latest long-range outlook suggests parts of southern and eastern Australia are likely to receive less rainfall than usual between July and September, while much of the country can expect above-average temperatures.

Below-average rainfall does not mean no rain, and individual weather events such as east coast lows could still bring heavy downpours.

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El Nino declared – here's what it means for Australia’s forecast

The last El Nino, in 2023-24, coincided with the nation’s driest August to October period on record but heavy east coast storms and tropical cyclones later delivered widespread summer rain.

Meteorologists also highlight the potential of other climate drivers to shape weather outcomes in Australia during the months ahead.

These include the Indian Ocean Dipole and Southern Annular Mode which may lessen of enhance the impact of El Nino through the second half of this year.