Climate Model Summary

Climate Model Summary Archive: 18 January 2011

Models predict La Niña event will persist through southern hemisphere summer


As detailed in the ENSO Wrap-up, a strong La Niña event continues in the Pacific.

Although most dynamical models surveyed by the Bureau of Meteorology indicate a gradual rise in Pacific Ocean temperatures during the coming months, they also show that sea surface temperatures (e.g. NINO3.4) are likely to remain at levels typical of a La Niña event during the first quarter of 2011.

The models surveyed here, with the exception of NCEP, predict the central Pacific will warm during the first quarter of 2011, with the NASA model predicting a faster decay of La Niña conditions relative to the other models.

The Bureau's POAMA model suggests that central Pacific Ocean temperatures will start to warm in coming months, with all thirty POAMA forecasts favouring a gradual weakening of La Niña conditions. However, despite a gradual weakening, POAMA predicts that the central Pacific Ocean will remain at temperatures typical of a La Niña event until at least the end of the southern hemisphere summer. A gradual weakening of the event, perhaps accelerating during the southern autumn, would be consistent with previous La Niña episodes.

Model Outlooks

The following table summarises the opinion of National Climate Centre climatologists regarding the outputs from various long range forecast models. The model set contains eight reputable ocean or coupled ocean/atmosphere climate models that take into account complex physical ocean processes. NCC's interpretation may not necessarily be the same as the organisations producing the model output. You are therefore encouraged to follow the hyperlinks to the various institutions listed in the table.

See About ENSO outlooks for details on the models and a summary of the terms used.

Forecast Start Date 1-3 MONTHS
(Feb 11 to Apr 11)
(May 11 to Jul 11)
Australian Bureau of Meteorology
3 January Cool/Neutral Neutral
System 3
1 December Cool/Neutral Neutral
GloSea *
UK Met Office
1 December Cool Cool/Neutral #
3 January Cool Cool
NASA Goddard GMAO (US)
1 December Cool/Neutral Neutral/Warm
Japan Met. Agency
1 December Cool/Neutral Neutral/Warm
Korean Met. Administration
1 November Cool/Neutral Neutral
BCC/CMA (China)
Unavailable Unavailable Unavailable

# Model forecast is run only until the end of May
* Note that this page requires a password, freely available from UK Met Office
Note that some links above may be updated to more recent forecasts than listed here.

POAMA Forecasts

The POAMA model, run at the Bureau of Meteorology, generates a new forecast every day for the following eight months starting with the latest observations. The average of the most recent 30 model runs predict La Niña conditions will gradually weaken over the coming months with a return to neutral conditions in the southern hemisphere autumn.

The IOD is currently neutral with the latest weekly value of the IOD index at +0.02. POAMA predicts that the IOD index will remain neutral through the southern hemisphere summer and into autumn.

March 2011

For the 30 runs of POAMA between 5 December 2010 and 3 January 2011, the average NINO3.4 temperature anomaly for March 2011 is −1.06°C and the frequency distribution is as follows:
below −0.8°C: 86.7.3% (Cool)
−0.8°C to +0.8°C: 13.3% (Neutral)
above +0.8°C: 0.0% (Warm)

June 2011

Similarly for June 2011 the average NINO3.4 index is −0.46°C and the frequency distribution is:
below −0.8°C: 16.7% (Cool)
−0.8°C to +0.8°C: 83.3% (Neutral)
above +0.8°C: 0.0% (Warm)

Similar data for other months can be accessed by following the "POAMA" link in the table above.

Users should exercise caution when interpreting these forecasts and are encouraged to view the actual model outputs by following the web links. Frequent updates of the latest observational data with relevant commentary are available on the Bureau's ENSO Wrap-Up page.

This survey last updated 5th January 2011.
Next update expected 19th January 2011.

See also the ENSO Wrap-up archive here.

Past climate model summaries