Australia’s Bureau of Meteorology reported today that warming of the tropical Pacific Ocean over the past several months has primed the climate system for an El Niño in 2014. However, said the BOM, in the absence of the necessary atmospheric response, warming has levelled off in recent weeks. Positive Southern Oscillation Index values and large areas of warm water in the western Pacific and off northwestern Australia are also counter to typical El Niño development.
Despite recent observations and some easing in the model outlooks, climate models surveyed by the Bureau still indicate El Niño is likely to develop by spring 2014. The Bureau’s ENSO Tracker remains at El Niño ALERT, indicating at least a 70% chance of El Niño developing in 2014.
Most international climate models surveyed by the Bureau indicate that SSTs in the equatorial Pacific Ocean are likely to warm further over the coming months. Despite some easing in the predictions of how much the equatorial Pacific will warm by, the majority of the surveyed models indicate that sea surface temperatures in the equatorial Pacific are likely to exceed El Niño thresholds before or during the southern hemisphere spring.
For Australia, El Niño is often associated with below-average rainfall over southern and eastern inland areas and above-average daytime temperatures over southern parts of the continent.
The Indian Ocean Dipole (IOD) is currently neutral. Model outlooks suggest the IOD is most likely to remain neutral through winter and spring. Positive IOD events often coincide with El Niño and are typically associated with large parts of southern and central Australia experiencing lower rainfall than usual.