Climate Model Summary

Climate Model Summary Archive: 2 March 2011

Models predict continued weakening of La Niña conditions


As detailed in the ENSO Wrap-up, La Niña conditions continue to weaken in the tropical Pacific, consistent with the expected life cycle of past La Niña events.

Most dynamical models surveyed by the Bureau of Meteorology indicate a continued warming of the cooler Pacific Ocean temperatures during the coming months with the rate of warming varying marginly between models. Sea surface temperatures (e.g. NINO3.4) are likely to become neutral by the southern winter 2011.

The Bureau's POAMA model suggests that central Pacific Ocean temperatures will warm through autumn, with all thirty POAMA forecasts favouring a gradual weakening of La Niña conditions and neutral conditions to persist through winter 2011. A gradual weakening of the event through 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
(Mar 11 to May 11)
(Jun 11 to Aug 11)
Australian Bureau of Meteorology
28 February Neutral Neutral
System 3
1 February Cool/Neutral Neutral
GloSea *
UK Met Office
1 February Cool/Neutral Neutral #
1 March Cool Cool/Neutral
NASA Goddard GMAO (US)
1 February Neutral/Warm Warm
Japan Met. Agency
1 January Neutral Warm^
Korean Met. Administration
1 January Cool Neutral^
BCC/CMA (China)
Unavailable Unavailable Unavailable

# Model forecast is run only until the end of July
^Model forecast is based on 1 January 2011 run and should be viewed with this consideration - updated forecasts are likely during the next fortnight

* 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 a return to neutral conditions by late autumn, with these conditions persisting through the southern winter.

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 autumn and winter seasons.

April 2011

For the 30 runs of POAMA between 30 January 2011 and 28 February 2011, the average NINO3.4 temperature anomaly for April 2011 is −0.29°C and the frequency distribution is as follows:
below −0.8°C: 0.0% (Cool)
−0.8°C to +0.8°C: 100.0% (Neutral)
above +0.8°C: 0.0% (Warm)

July 2011

Similarly for July 2011 the average NINO3.4 index is 0.30°C and the frequency distribution is:
below −0.8°C: 0.0% (Cool)
−0.8°C to +0.8°C: 100.0% (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 2nd March 2011.
Next update expected 16th March 2011.

See also the ENSO Wrap-up archive here.

Past climate model summaries