The Australia Bureau of Meteorology says the chance of an El Nino event developing in 2012 has been reduced with tropical Pacific Ocean temperatures remaining at neutral levels following cooling in this region since the beginning of September. This is consistent with atmospheric ENSO indicators which also remain at neutral levels.
"The majority of dynamical models surveyed by the Bureau of Meteorology suggest that sea surface temperatures in the tropical Pacific will maintain values in the neutral range for the remainder of 2012 and early 2013, with one model suggesting weak El Nino conditions remain possible.... This reduction in the likelihood of an El Nino event in 2012 is consistent with an easing in the strength of the warming signal over previous months."
Additionally, the bureau says this year has seen a positive Indian Ocean Dipole (IOD), which has contributed to below-average rainfall across large parts of Australia during recent months. "The positive IOD pattern in the Indian Ocean has declined over the last few weeks, and has now returned to neutral levels. This is typical behavior of the IOD, which usually breaks down before the onset of the Australian monsoon," it states.