El Niño remains possible in 2014
Despite some warming of the tropical Pacific Ocean over the past month, the El Niño–Southern Oscillation (ENSO) remains neutral. However, models continue to suggest an El Niño remains possible in 2014, and hence the Bureau’s ENSO Tracker remains at WATCH status, indicating at least double the normal risk of an El Niño developing by the end of the year.
Although tropical Pacific Ocean surface temperatures are within neutral range, an area of the sub-surface is warmer than average. A late season El Niño remains possible if these warmer waters rise to the surface and then affect atmospheric circulation, or if another sustained westerly wind burst develops in the western Pacific.
The majority of international climate models surveyed by the Bureau indicate central tropical Pacific surface temperatures will remain warmer than average, and may exceed El Niño thresholds by the end of the year. These model outlooks and current observations mean the Bureau’s ENSO Tracker remains at WATCH status, indicating at least a 50% chance (double the normal likelihood) of an El Niño forming in 2014.
El Niño is often associated with below-average rainfall over large parts of southern and eastern inland areas of Australia and above-average daytime temperatures over southern Australia. Such impacts can often occur while an event is developing, as experienced in some locations over the past several months.
The negative Indian Ocean Dipole (IOD) in the tropical Indian Ocean has shown signs of weakening. Waters to the north of Australia and in the Timor Sea have cooled over the past two weeks. All climate models surveyed by the Bureau indicate the IOD will continue to weaken, with neutral conditions likely to return during the austral spring.
Information courtesy of the Bureau of Meteorology (Issued 9th Sept 2014).