Climate Model Summary

Updated: Unavailable

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. It is updated monthly.


Models maintain outlooks for El Niño though winter and spring

The tropical Pacific Ocean has warmed over the last month, with surface temperatures now just shy of typical El Niño values. All surveyed models suggest further warming will occur, potentially exceeding El Niño thresholds in May. Current wind and sub-surface patterns also support further warming of sea surface temperatures in the central and eastern tropical Pacific.

Model forecasts spanning the traditional ENSO transition period, February to May, generally have lower accuracy than forecasts made at other times of year. However, as we are nearing the end of this period, and with all eight models consistent in their outlooks for further warming in the Pacific Ocean, these outlooks cannot be discounted.

The Indian Ocean Dipole (IOD) generally has little impact on Australian climate from December to April due to the natural position of the monsoon trough at this time of year. The latest model outlooks for the IOD index from May are mixed with little to suggest a transition to either a positive or negative phase of the IOD during the current forecast period.

For more details on both ENSO and the IOD, please see the ENSO Wrap-Up.

Average of international model outlooks for NINO3.4

The average NINO3.4 value taken from 7 international models at a three month outlook
The average NINO3.4 value taken from 7 international models at a five month outlook
Graphs based on the ensemble mean for the most recent model run.

The arrows on the dials above indicate the combined average of monthly NINO3.4 outlooks from a survey of international global climate models. Note that the individual model runs vary around the average.

More information:

NINO3.4 outlook

The latest NINO3.4 forecasts (initialised in April) indicate the tropical Pacific Ocean is likely to warm over the coming months, with all models indicating El Niño thresholds are likely to be reached or exceeded in May. All models suggest the central Pacific Ocean will continue to warm past mid-year, with the average September (ensemble mean) forecasts for NINO3.4 more than 1.6 °C above normal.

Model forecasts spanning the February to May period tend to have reduced accuracy, and hence greater spread. This period is known as the "predictability barrier" as the temperature gradients across the tropical Pacific Ocean naturally weaken at this time of year, meaning the Pacific can undergo rapid change. Model outlooks for predictions made during this time should generally be used carefully, though a degree of confidence can be placed in the current outlooks as there is strong consensus among the models that warming above El Niño thresholds will occur by June.

The most recent NINO3.4 value is +0.7 °C for the week ending 12 April 2015. NINO3.4 values between –0.8 °C and +0.8 °C typically indicate neutral ENSO conditions.

The following graph shows 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.

NINO3.4 covers the central Pacific region.

NINO3.4 Outlook

Nino 3.4 2 month outlook Models information
Graphs based on the ensemble mean for the most recent model run.

Indian Ocean Dipole (IOD) outlook

The IOD does not affect Australian climate from December to April. This is due to the monsoon trough moving southwards over the regions of ocean where the IOD occurs. This alters the wind patterns, and results in negative or positive IOD patterns being unable to form during these months.

Current forecasts beyond the December to April low influence period suggest the IOD will remain neutral until at least spring. The state of the tropical Indian Ocean will be monitored closely as the influence of the monsoon weakens during the austral autumn, and the IOD starts to have more influence on Australian climate.

The following graph shows 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.

IOD Outlook

These form controls display per month outlook graphs.

Latest POAMA IOD outlook Models information

Graphs based on the ensemble mean for the most recent model run.

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 (started on 12 April) predicts NINO3.4 is likely to continue to warm throughout the forecast period. All ensemble members (forecast scenarios) anticipate El Niño thresholds to be met in May and remain above El Niño thresholds until the end of the year. This agreement amongst ensemble members suggests a higher degree of predictability, despite being in a period where model skill is generally low. The following forecast values (at the top of the table) are for POAMA's ensemble mean.

Month 2

NINO3.4 forecast value: Not available

Range Category Frequency distribution
below −0.8 °C: (Cool) Unavailable
  (Neutral) Unavailable
above +0.8 °C: (Warm) Unavailable

Month 4

NINO3.4 forecast value: Not available

Range Category Frequency distribution
below −0.8 °C: (Cool) Unavailable
  (Neutral) Unavailable
above +0.8 °C: (Warm) Unavailable

Month 6

NINO3.4 forecast value: Not available

Range Category Frequency distribution
below −0.8 °C: (Cool) Unavailable
  (Neutral) Unavailable
above +0.8 °C: (Warm) Unavailable

More information:

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.

Agency/Source/Provider Latest
NINO3.4
Latest
IOD
Model Model run used in this survey:
BOM - Bureau of Meteorology View NINO3.4 data
View IOD data POAMA
Unavailable
Meteorological Service of Canada View NINO3.4 data (via IRI multi model plume) Unavailable CanSIPS Unavailable
ECMWF (EU) View NINO3.4 data Not public System4 Unavailable
JMA View NINO3.4 data Unavailable JMA/MRI-CGCM Unavailable
METEO-FRANCE View NINO3.4 data (via IRI multi model plume) Not public ARPEGE 1 April 2013
NASA - GMAO (USA) View NINO3.4 data
View IOD data GEOS5
1 April 2013
NOAA - NCEP (USA) View NINO3.4 data
Unavailable CFSv2 Unavailable
UKMO View NINO3.4 data Not public GloSea5 Unavailable

Product Code: IDCKGLM000

Next update expected Unavailable

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