Climate Model Summary

Models continue to favour El Niño by mid-year

The El Niño-Southern Oscillation (ENSO) is currently neutral. International models suggest it will remain so through the southern autumn. All models indicate warming in the tropical Pacific Ocean is likely over the next six months. Four out of eight models suggest El Niño thresholds will be reached by June, and seven models now indicate El Niño by August.

The Indian Ocean Dipole (IOD) has little influence on Australia from December to April. Outlooks suggest a neutral IOD is likely for autumn and early winter, but five of six models suggest an increased chance of a positive IOD by August. If a positive IOD were to occur with El Niño, this can reinforce the typical dry signal observed in Australia during El Niño. However, it should be noted that model accuracy during early autumn (for both ENSO and IOD outlooks) is lower than at other times of year.

NINO3.4 outlook

The latest NINO3.4 model outlooks indicate temperatures in the central tropical Pacific Ocean are likely to warm over the next six months. The average of all international models suggests the El Niño-Southern Oscillation (ENSO) will remain neutral until at least the end of the southern autumn.

The most recent weekly NINO3.4 value to 26 March is +0.2 °C. By June, the average of all the models is +0.8 °C, meeting the El Niño threshold. By August, seven of the eight models exceed the El Niño threshold. This outlook straddles the autumn predictability barrier - typically the ENSO transition period - during which most models have their lowest outlook accuracy. However, the consistency across the models for Pacific Ocean temperatures to warm, gives a degree of confidence in these outlooks.

The Bureau routinely monitors oceanic and atmospheric conditions and model outlooks. NINO3.4 values that persist below −0.8 °C typically indicate La Niña, while persistent values above +0.8 °C typically indicate El Niño.

Indian Ocean Dipole (IOD) outlook

The latest weekly IOD index value to 26 March is +0.2 °C, within the neutral range. The IOD is typically unable to form between December and April, while the monsoon trough is active in the southern hemisphere.

Outlooks for April and June indicate a neutral IOD is likely, but five of six models suggest a positive IOD is possible by August. However, model skill is low at this time of year, so caution should be exercised when using these forecasts.

A positive IOD is typically associated with below average winter-spring rainfall over southern and central Australia. When a positive IOD coincides with an El Niño, the typical dry signal may be enhanced.

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 26 March) indicates NINO3.4 will warm gradually early in the outlook period, with a stronger rate of warming likely from June. POAMA suggests El Niño thresholds could be exceeded in August, and sustained at these levels until the end of the forecast period. However, this forecast straddles the autumn predictability barrier, meaning forecast skill beyond autumn is low.

The forecast values, shown below in bold, are for 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 26 March 2017

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) 0.38 0.17 0.33 0.63 0.90 1.09 1.22
Model cool frequency (<−0.8°C) 0% 0% 0% 0% 0% 0% 0%
Model neutral frequency 100% 100% 100% 75.76% 39.39% 27.27% 15.15%
Model warm frequency (>+0.8°C) 0% 0% 0% 24.24% 60.61% 72.73% 84.85%

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.