Climate Model Summary

Climate Model Summary Archive: 22 August 2012

Issued on Wednesday 22 August 2012 |

El Niño remains likely for 2012

Summary

As detailed in the ENSO Wrap-Up, tropical Pacific Ocean temperatures have approached or exceeded values commonly associated with the early stages of an El Niño event, however atmospheric indicators of ENSO such as trade winds and cloud patterns have yet to reach El Niño thresholds. To be considered an ENSO event, climatologists look for signals that indicate the ocean and atmosphere are reinforcing each other (i.e., "coupled"), and hence will be sustained over several months.

All dynamical models surveyed by the Bureau of Meteorology suggest that sea surface temperatures in the tropical Pacific will maintain values close to or above El Niño thresholds before returning to neutral values towards the end of 2012 or early 2013. However, results from individual models continue to show a moderate to high level of spread in their forecasts, suggesting there continues to be a range of potential scenarios. Climatologists are monitoring conditions and outlooks closely for any further developments, particularly in terms of the coupling of the tropical Pacific Ocean and atmosphere.

Model Outlooks

The following table summarises the opinion of National Climate Centre (NCC) climatologists regarding the outputs from various long range forecast models. The model set contains seven 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.

MODEL /
GROUP
Forecast Start Date 1-3 MONTHS
(Sep 2012 to Nov 2012)
4-6 MONTHS
(Dec 2012 to Feb 2013)
POAMA
Australian Bureau of Meteorology
1 August Neutral/Warm Neutral/Warm
CFSv2
NCEP (US)
21 August Neutral/Warm Neutral
GEOS-5
NASA Goddard GMAO (US)
1 August Warm Warm
ARPEGE*
MeteoFrance
1 August Neutral/Warm Neutral/Warm
System 4
ECMWF (EU)
1 August Warm Neutral
JMA/MRI-CGCM
Japan Met. Agency
1 August Warm Warm
GloSea
UK Met Office
1 August Warm Warm #

# Forecast ends before February.
* A password is currently required to view this forecast.

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 on day 1 of each month for the following eight months. The most recent model run (August) predicts NINO3.4 will remain close to the El Niño threshold throughout the forecast period.

The IOD remains in a neutral phase, although the IOD index is currently positive with the most recent value of +0.7 recorded for the week ending 19 August 2012. The latest forecast from the POAMA model predicts the index will return to neutral values in spring and remain close to zero for the remainder of the forecast period.

October 2012

The most recent POAMA model run (August) predicts the average NINO3.4 temperature anomaly for October 2012 will be +0.6 °C and the frequency distribution is as follows:
below −0.8 °C: 0.0% (Cool)
−0.8 °C to +0.8 °C: 90.0% (Neutral)
above +0.8 °C: 10.0% (Warm)

January 2013

For January 2013, the average NINO3.4 temperature anomaly is +0.7 °C and the frequency distribution is as follows:
below −0.8 °C: 0.0% (Cool)
−0.8 °C to +0.8 °C: 56.7% (Neutral)
above +0.8 °C: 43.3% (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 22 August 2012.
Next update expected 5 September 2012.


See also the ENSO Wrap-up archive here.

Past climate model summaries