Climate Model Summary

Models now favour a weak La Niña in 2016

The tropical Pacific Ocean has cooled significantly since the peak of the 2015-16 El Niño in November, with temperatures dropping into the neutral range in mid-May. However, latest outlooks have eased a little in their estimates of further cooling. Three of the eight models surveyed (Canada, European and US-NASA) now maintain a cool, but neutral, outlook throughout the southern winter and spring. The Bureau's model briefly exceeds the La Niña threshold in July and August before returning back to neutral levels. The remaining four models indicate La Niña thresholds will be met at some point during spring, although the timing varies between models.

All models surveyed indicate a negative Indian Ocean Dipole (nIOD) is likely to develop during winter. The IOD index has already exceeded the negative IOD threshold (–0.4 °C) for four consecutive weeks; though will need to exceed this threshold for another month for 2016 to be considered a nIOD year. Currently, models suggest a nIOD may last until late spring.

While ENSO and the IOD can be strong influences on Australian climate at certain times of year, other factors may also influence our climate, such as sea surface temperatures around our northern coast.

NINO3.4 outlook

The latest NINO3.4 outlooks (initialised in June) indicate that sea surface temperatures across the central tropical Pacific Ocean are likely to continue cooling, although most models suggest the rate of cooling is likely to slow.

The all-model average NINO3.4 outlook for July is −0.7 °C; just shy of the La Niña threshold. This average value is maintained through September, dropping to −0.8 °C by November. There is a wide spread in most model ensembles beyond spring, with members divided between continued cooling in the tropical Pacific Ocean, and a return to near-normal (neutral) temperatures.

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 +0.2 °C for the week ending 19 June 2016. NINO3.4 values below −0.8 °C typically indicate La Niña events.

Indian Ocean Dipole (IOD) outlook

The Indian Ocean Dipole (IOD) can affect Australian climate from May to December. Current outlooks (initialised in June) all suggest a negative IOD is likely to develop during the winter and spring months.

The most recent IOD index value is −0.6 °C for the week ending 19 June 2016. This is the third consecutive week below the negative IOD threshold of −0.4 °C. Generally, IOD events last for at least a couple of months. Model outlooks, combined with recent observations make it likely that 2016 will be a negative IOD year. A negative IOD typically enhances rainfall over southern Australia during winter and spring.

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 19 June) suggests NINO3.4 will continue to cool during June, exceeding La Niña thresholds in July. By September, POAMA suggests a return to neutral levels, but maintaining 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

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 19 June 2016

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) -1.01 -1.06 -0.75 -0.68 -0.61 -0.63 -0.67
Model cool frequency (<−0.8°C) 90.91% 84.85% 42.42% 36.36% 24.24% 21.21% 30.3%
Model neutral frequency 9.09% 15.15% 57.58% 63.64% 75.76% 78.79% 69.7%
Model warm frequency (>+0.8°C) 0% 0% 0% 0% 0% 0% 0%

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.

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