Climate Model Summary

Climate Model Summary Archive: October 2013

Neutral ENSO for austral summer

Neutral conditions persist in the tropical Pacific. All of the international climate models surveyed by the Bureau of Meteorology indicate that this neutral state will persist throughout the remainder of spring and into summer.

The Indian Ocean Dipole (IOD) is also neutral. All models indicate neutral conditions will continue until at least the onset of the Australian monsoon (around November), after which the IOD typically has little impact upon Australian climate until the autumn–winter months.

NINO3.4 Outlook

The latest NINO3.4 forecasts (initialised in October) from all available models indicate neutral El Niño-Southern Oscillation (ENSO) conditions are likely to persist through to the austral autumn 2014. Most models suggest the NINO3.4 region will warm over the next six months, but remain within the neutral range. The most recent NINO3.4 value is −0.3 °C for the week ending 13 October 2013. (NASA data was not available due to the US Government shut-down).

Indian Ocean Dipole (IOD)

The IOD index remains neutral with a latest weekly value of 0.0 °C for the week ending 13 October 2013. This neutral period follows on from a negative IOD event which became established during May 2013 and contributed to above average rainfall over parts of southern Australia from May to July. The IOD consensus outlook from the four available models, indicates neutral values are likely to persist until at least the onset of the Australian monsoon. After this time, the IOD typically has little effect on Australian climate until the autumn–winter months. (NASA data was not available due to the US Government shut-down).

Predictive Ocean Atmosphere Model for Australia (POAMA)

POAMA, run at the Bureau of Meteorology, generates an eight-monthly forecast on the first day of each month. The most recent model run (started in October) predicts NINO3.4 is likely to warm throughout the forecast period but remain within neutral values. The following forecast values are for the ensemble mean.

POAMA archive data is available here.

ENSO Dials

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

ENSO dial month+1 ENSO dial month+3 ENSO dial month+5

NINO3.4 outlook bar-graphs

The following graphs 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 bar graph month+1 NINO3.4 bar graph month+3 NINO3.4 bar graph month+5

IOD outlook bar-graphs

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 bar graph month+1 IOD bar graph month+3 IOD bar graph month+5

Past climate model summaries