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.


El Niño likely to strengthen and persist through 2015

El Niño remains well established in the tropical Pacific. All models surveyed indicate further warming of the tropical Pacific is likely over the coming months, and that the 2015 El Niño will remain in place for the rest of the year.

Recent and vigorous tropical cyclone activity, including a rare July southern hemisphere cyclone in the western Pacific, has brought about a strong reversal of the Pacific trade winds. This has resulted in enhanced warming of sea surface temperatures (SSTs) across the Pacific. All of the main SST indices have remained above El Niño thresholds for several weeks, with collective values not seen since the strong 1997-98 El Niño. Atmospheric indicators, such as wind, cloud and pressure patterns, also remain consistent with a well-established El Niño.

All models indicate SSTs in the central tropical Pacific (i.e., NINO3.4) will exceed 2 °C above average by October, with an all-model average temperature anomaly of +2.6 °C. The most recent NINO3.4 value is +1.5 °C for the week ending 12 July 2015. Persistent NINO3.4 values above +0.8 °C typically indicate El Niño.

The Indian Ocean Dipole (IOD) is currently neutral. Three out of the five models that issue IOD forecasts suggest development of a positive IOD is likely in coming months. Two models maintain a neutral outlook. Positive IOD events tend to reduce rainfall in southern and central Australia during the winter and spring months, and can exacerbate rainfall deficiencies caused by El Niño.

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 July) indicate that sea surface temperatures across the central tropical Pacific Ocean are likely to persist at above El Niño thresholds through until the end of 2015. The all-model average NINO3.4 outlook for October is just above +2.6 °C, increasing to +2.7 °C by December. Since the start of the satellite era of ocean observations in the late 1970's, NINO3.4 values this large have only been observed during the 1982-83 and 1997-98 El Niño events. Individual model values range between +2.2 °C and +3.4 °C for December; all well above the El Niño threshold and indicative of a substantial El Niño.

The most recent NINO3.4 value is +1.5 °C for the week ending 12 July 2015. NINO3.4 values above +0.8 °C typically occur during El Niño events.

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
Due to strong NINO3.4 outlooks from all models, these graphs have been modified from last month to better present the forecast data.
Graphs are based on the ensemble mean for the most recent model run.

Indian Ocean Dipole (IOD) outlook

The Indian Ocean Dipole is currently neutral. Three out of five model outlooks suggest some tendency towards a positive IOD by spring 2015, while the other two suggest a neutral outlook. A positive IOD typically reduces rainfall in central and southern Australia, and can therefore exacerbate El Niño driven rainfall deficiencies.

The most recent IOD index value is +0.3 °C for the week ending 12 July 2015 following three weeks of weak-negative values. Sustained IOD index values above +0.4 °C typically indicate a positive IOD event.

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 19 July) predicts that NINO3.4 is likely to remain at least +2 °C above average - well above El Niño thresholds - until at least the end of the year. The following forecast values (at the top of the table) are for POAMA's NINO3.4 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-CPS2 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.