Climate Model Summary
Model Summary forecasts are no longer available
We are streamlining some climate pages including removal of the Model Summary.
From 10 December our climate information is available on the Southern Hemisphere monitoring and Southern Hemisphere outlooks pages.
If you have any feedback, please use our Feedback Form.
Average of international model outlooks for the Niño3.4 index
Average of international model outlooks for the Indian Ocean Dipole (IOD) index
Dial details
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.
The ENSO and IOD dials are calculated by simply averaging the ensemble means from all the models surveyed. Values are not representative of the potential spread of the forecast outcomes. Therefore, the dials are intended to be used as a quick reference to determine whether the models are showing a warming trend, a cooling trend, or neither. More information is provided in the graphs presented in other sections.
More information:
Niño3.4 covers the central Pacific region.
Niño3.4 multi-model forecast for the months ahead
Bar graph details
The graphs are based on the ensemble mean for the most recent model run.
These graphs show the average forecast value of Niño3.4 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.
Niño3.4 recent observations and multi-model long-range forecast
Timeseries graph details
This timeseries graph shows recent monthly observations, as well as long-range forecasts for the Niño3.4 index from a range of international models. Monthly observations are from the OISSTv2 (1991-2020 base period) dataset, represented by the left side dashed line. Each coloured line to the right represents the ensemble mean forecast from nine international climate models including the Bureau's model. The graph is updated each month, with available data updated fortnightly.
More information:
IOD index multi-model forecast for the months ahead
Bar graph details
The graphs are based on the ensemble mean for the most recent model run.
These 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.
More information:
Sea surface temperature graphs
Australian climate is influenced by sea surface temperature and atmospheric patterns in the Pacific, Indian and Southern ocean regions. Specific regions are monitored, as they can indicate the presence, or potential development, of ENSO (El Niño/La Niña), Indian Ocean Dipole (IOD) phases and Southern Annular Modes. Pacific and Indian ocean indices are updated fortnightly, but the SAM index can change rapidly so it is updated daily. The first SAM button matches the Niño and IOD fortnightly issue date. During the following fortnight the 'Latest SAM' chart will diverge.
Niño34 predictions for the next 5 months
Niño34 probabilities
Product code: IDCK000073
More information:
Model details
Model selection
All the models included in this page have been documented in the peer-reviewed international scientific literature and have skill in predicting El Niño-Southern Oscillation (ENSO) and Indian Ocean patterns. They are all coupled General Circulation Models, and hence simulate both atmospheric and oceanic processes using physics rather than statistics. Most have been run routinely for a number of years and are subject to regular revision and update with the aim of continuous improvement. They represent the state-of-the-art of climate prediction systems and offer useful guidance up to about nine months. The majority of models used in our survey are formally recognised by the World Meteorological Organization as Global Producing Centres for long-range forecasts.
All models use an ensemble method, where several forecasts are run at the same time using slightly different initial conditions. While all models use ensemble techniques, the number of ensembles differs for each model.
The data presented on these pages is the 'ensemble mean' which is the average of all the model-runs performed by each model, each month. The ensemble mean therefore flattens out the potential forecast outcomes and doesn't show the full spread of the possible forecast scenarios.
More information about these models
[an error occurred while processing this directive]The webpage
This webpage surveys the latest output from several reputable climate models developed at leading international climate agencies. Data from these models is analysed and displayed in graphs and dials to show how temperature patterns in the Indian and Pacific ocean are likely to change over the coming six-months. These patterns in the oceans have been shown to have a significant impact on Australian temperature and rainfall patterns (e.g. cooling of the tropical Pacific Ocean during La Niña events is typically associated with increased rainfall and cooler daytime temperatures in Australia).
When the models are in agreement, then there is higher confidence in the model outlooks. When the models are showing a large spread or large variety of outcomes, there is a larger amount of uncertainty associated with the forecast.
The models
All the models included in this page have been documented in the peer-reviewed international scientific literature and have skill in predicting El Niño-Southern Oscillation (ENSO) and Indian Ocean patterns. They are all coupled General Circulation Models, and hence simulate both atmospheric and oceanic processes using physics rather than statistics. Most have been run routinely for a number of years and are subject to regular revision and update with the aim of continuous improvement. They represent the state-of-the-art of climate prediction systems and offer useful guidance up to about nine months. The majority of models used in our survey are formally recognised by the World Meteorological Organization as Global Producing Centres for long-range forecasts.
Update schedule
The Climate Model Summary is updated on the 12th of each month (or the next working day following the 12th) when model data becomes available. Data for the Bureau's model, ACCESS–S, is updated fortnightly along with several other models that also provide more frequent updates during the month.
The ensemble technique
All models use an ensemble method, where several forecasts are run at the same time using slightly different initial conditions. While all models use ensemble techniques, the number of ensembles differs for each model.
Important note
The data presented on these pages is the 'ensemble mean' which is the average of all the model-runs performed by each model, each month. The ensemble mean therefore flattens out the potential forecast outcomes and doesn't show the full spread of the possible forecast scenarios.
The dials
The ENSO and IOD dials (from the Overview section) are calculated by simply averaging the ensemble means from all the models surveyed. Values are not representative of the potential spread of the forecast outcomes. Therefore, the dials are intended to be used as a quick reference to determine whether the models are showing a warming trend, a cooling trend, or neither. More information is provided in the graphs presented in other sections.
Background information
Related sites
[an error occurred while processing this directive]
History
Model data are provided for Bureau of Meteorology use by the agencies detailed in Model Summary – Models. Respective agency copyright applies to these data.
La Niña development likely in austral winter 2016
The tropical Pacific has continued to cool. Climate models indicate this cooling trend is expected to continue, with six out of eight models suggesting La Niña is likely to form during the austral winter. However, one of these six models indicates this may be only a short-lived event.
The Indian Ocean Dipole (IOD) outlooks suggest a negative IOD may develop during winter. However, model skill is low at this time of year, so caution should be exercised when using these forecasts.
While ENSO and the IOD can be strong influences on Australian climate at certain times of year, other factors may also influence our climate —see our Climate Outlooks page for the latest rainfall and temperature outlooks.
NINO3.4 outlook
The latest NINO3.4 outlooks (initialised in May) indicate that sea surface temperatures across the central tropical Pacific Ocean are likely to continue cooling into the austral winter.
The all-model average NINO3.4 outlook for June is −0.7 °C; just above the La Niña threshold of −0.8 °C. By August, the model average drops to −1.2 °C, but then levels off to −1.1 °C in October.
Six out of eight models indicate La Niña will form, but the POAMA model suggests only a short-lived La Niña. A seventh model (ECMWF) briefly falls into La Niña levels during July, but does not maintain its strength for long enough to be considered an event.
Oceanic and atmospheric conditions as well as the model outlooks will be monitored closely during the ENSO transition period. The most recent NINO3.4 value is +0.6 °C for the week ending 15 May 2016. NINO3.4 values above +0.8 °C (below −0.8 °C) typically indicate El Niño (La Niña) events.
Indian Ocean Dipole (IOD) outlook
The Indian Ocean Dipole (IOD) can affect Australian climate from May to November. Current outlooks (initialised in May) all suggest a negative IOD is likely to develop during winter. However, outlook accuracy for the IOD at this time of year is low. A negative IOD typically enhances rainfall over southern Australia during winter and spring.
The most recent IOD index value is −0.1 °C for the week ending 15 May 2016. Sustained IOD index values below −0.4 °C typically indicate a negative IOD event.
Predictive Ocean Atmosphere Model for Australia (POAMA)
POAMA, run at the Bureau of Meteorology, generates an eight-month forecast each fortnight. The most recent model run (generated 8 May) suggests NINO3.4 will cool rapidly during May, exceeding La Niña thresholds in June, return to neutral levels in September, and maintain values close to the La Niña threshold until the end of the year. The forecast values, shown below in bold, are for POAMA's ensemble mean.
Product code: IDCKGL0000
Unless otherwise noted, all maps, graphs and diagrams in this page are licensed under the Creative Commons Attribution 4.0 International Licence
