Further easing of El Niño; likelihood of neutral state to follow

El Niño remains strong, but continues its gradual decline. Climate models suggest a return to neutral levels in the second quarter of 2016.
February 3, 2016

Close to the equator, the surface of the Pacific Ocean has now cooled by 0.5 °C since the El Niño peaked in late 2015. Below the ocean surface, cooler than average waters now extend into the central tropical Pacific Ocean. In the atmosphere, trade winds have recently returned to near-normal levels in the central and eastern Pacific, although the Southern Oscillation Index (SOI) has been strongly negative in recent weeks. The Australian Government\'s Bureau of Meteorology said in thei briefing on February 2, 2016 that it is not unusual to see big fluctuations in the SOI due to the passage of tropical systems, and hence its value may not be representative of the overall ENSO state.

Based on the 26 El Niño events since 1900, around 50% have been followed by a neutral year, and 40% have been followed by La Niña. Models suggest the neutral state is the most likely for the second half of 2016, followed by La Niña, with a repeat El Niño assessed as very unlikely. Historically, the breakdown of strong El Niño events brings above average rainfall to some-but not all-parts of Australia in the first half of the year.