Climate Model Summary

Models continue to favour El Niño development in spring; positive IOD possible

The El Niño–Southern Oscillation (ENSO) is currently neutral—neither El Niño nor La Niña. Over the coming months, most surveyed models predict the central tropical Pacific Ocean will slowly continue to warm warm. Four of the eight models suggest El Niño thresholds are likely to be reached by October, increasing to six by December.

El Niño is often, but not always, associated with below average rainfall across eastern and northern Australia during winter and spring. Daytime temperatures also tend to be above average over southern Australia.

The Indian Ocean Dipole (IOD) is currently neutral. Three of six climate models suggest a positive IOD event is possible, with a fourth close to meeting thresholds.

NINO3.4 outlook

The El Niño–Southern Oscillation (ENSO) remains neutral. The most recent weekly NINO3.4 value (to 15 July) is +0.5 °C, and while warmer than average, it is still below El Niño levels.

Most surveyed models predict the NINO3.4 index will rise progressively over the coming months. Four of the eight models indicate that the NINO3.4 index is likely to reach values consistent with El Niño by October. This number increases to six by December.

Persistent NINO3.4 values above +0.8 °C typically indicate El Niño, while values below −0.8 °C typically indicate La Niña.

Indian Ocean Dipole (IOD) outlook

The Indian Ocean Dipole (IOD) is currently neutral. The most recent weekly IOD index value (to 15 July) is −0.1 °C. Three of the six models suggest a positive IOD event is likely during the forecast period. A fourth model meets the positive thresholds for one month, but doesn't persist for long enough to become an event.

A positive IOD event typically reduces winter–spring rainfall in central and southern Australia, and can therefore exacerbate any potential El Niño driven rainfall deficiencies.

Predictive Ocean Atmosphere Model for Australia (POAMA)

POAMA, run at the Bureau of Meteorology, generates a nine-month forecast each fortnight. The most recent model run (generated 15 July) indicates NINO3.4 will maintain values close to the long-term average for the forecast period.

POAMA's Indian Ocean Dipole (IOD) outlook suggests the IOD will remain neutral during the southern winter and spring months.

The forecast values, shown below in bold, are POAMA's ensemble mean.

Product code: IDCKGL0000

Australian climate is influenced by temperature patterns in the Pacific and Indian Oceans. This page provides information on Pacific and Indian Ocean outlooks for the coming six months based on a survey of international climate models.

Further details: ENSO Wrap-Up (ENSO and IOD); Climate Outlooks

Average of international model outlooks for NINO3.4

Average of international model outlooks for the Indian Ocean Dipole (IOD)

Based on the ensemble mean for the most recent model run.

The arrows on the dials indicate the combined average of monthly outlooks from a survey of international global climate models. Note that the individual model runs vary around the average.

More information:

NINO3.4 covers the central Pacific region.

Graphs

Nino 3.4 2 month outlook Models information
Graph details

The graphs are based on the ensemble mean for the most recent model run.

These graphs show the average forecast value of NINO3.4 for each international model surveyed for the selected calendar month. If the bars on the graph are approaching or exceeding the blue dashed line, there is an increased risk of La Niña. Similarly, if the bars on the graph are approaching or exceeding the red dashed line, there is an increased chance of El Niño.

Graphs

Latest POAMA IOD outlook Models information
Graph details

The graphs are based on the ensemble mean for the most recent model run.

Thse graphs show the average forecast value of the IOD index for each international model surveyed for the selected calendar month. If the majority of models are approaching or exceeding the blue dashed line, then there is an increased risk of a negative IOD event. If the majority of models are approaching or exceeding the red dashed line, then there is an increased risk of a positive IOD event.

POAMA Long-Range Outlook

Issued 15 July 2018

Updated fortnightly

These model forecasts of the El Niño – Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) are generated by the Predictive Ocean Atmosphere Model for Australia (POAMA), a dynamical computer model of the climate system run at the Bureau of Meteorology. They are included in the monthly model summary of predictions from POAMA and other models operated by international organisations.

POAMA outlooks provide forecasts out to nine months ahead. The model ensemble distributions shown here provide a range of possible developments in sea surface temperature (SST) in the equatorial Pacific Ocean (NINO regions) and for the Indian Ocean.

NINO34 predictions for the next 9 months.

Skip to past graph to table of values

Outlook graph for selected indice

NINO34 probabilities

Click dates in the first row to see probability graphs
Outlook for month
NINO34 (°C) 0.12 -0.09 -0.02 0.05 0.08 0.10 0.13
Model cool frequency (<−0.8°C) 0% 0% 0% 0% 0% 0% 0%
Model neutral frequency 100% 100% 100% 100% 96.97% 93.94% 93.94%
Model warm frequency (>+0.8°C) 0% 0% 0% 0% 3.03% 6.06% 6.06%

Model details

The models used within our survey are listed below with links to their agency homepages, model output and technical information about the model.

Model data are provided for Bureau of Meteorology use by the agencies detailed in the Models section. Respective agency copyright applies to these data.