The Bureau of Meteorology (BoM) is a step closer after the Bureau of Meteorology issues an alert. “The Bureau’s *ENSO [El Niño Southern Oscillation] Outlook has been shifted to El Niño ALERT, indicating a 70% chance of El Niño forming this year,” the BoM said on Tuesday afternoon. “This equates to roughly three times the normal chance of an El Niño forming.”

The BoM uses both observations and forecasts from several oceanic and atmospheric indicators to monitor whether El Niño, La Niña or neutral conditions are present in the Pacific Ocean, including sea surface temps, winds, climate models and the Southern Oscillation Index (SOI). The SOI dropped below the -7 threshold on 16 May for the first time since mid-2020 and continues to plummet. Negative values of -7 or lower need to be sustained for around three months for the BoM to officially declare an El Niño, with the current alert issued after two months of -7 or lower.