El Niño–Southern Oscillation (ENSO)

(Issued 28 May 2024)

• The Bureau of Meteorology’s (BoM) El Niño-Southern Oscillation (ENSO) status is currently neutral.
• The Bureau's ENSO Outlook is at La Niña Watch, due to early signs that an La Niña event might form in the Pacific Ocean later in 2024. A La Niña Watch does not guarantee that a La Niña will develop.
• Oceanic and atmospheric indicators are also neutral.
• Three models show SST cooling to La Nina levels by August while the remaining four models remain neutral.
• Although ENSO forecast skill has historically increased after mid-autumn, model forecasts are still showing a spread of possible conditions.

Model agreement

• The figure below shows forecasts from international models for sea surface temperature anomalies in the Niño 3.4 region for 9 overlapping 3-month periods. For more information on this figure visit the IRI website.
• All models are forecasting a cooling trend in this part of the tropical pacific for the next several months. This is consistent with the breakdown of the 2023 El Niño event.
• There is wide variation in the model forecasts, particularly across the longer timeframes.  A cluster of these models suggests that the cooling trend could continue over the coming months meeting thresholds (0.5°C) that the American meteorological agencies use to indicate a La Niña state.
• DPI’s advice is that forecasts of La Niña forming are premature at this stage. It is important to monitor conditions closely over the coming month using the wider variety of indicators and thresholds used by the Australian BoM to track ENSO and its impacts on seasonal climate in Australia.