The jury is still out on a whether moisture-bearing La Nina pattern will develop over the Pacific Ocean this spring and summer, but it remains a possibility according to the weather bureau.

The Bureau of Meteorology’s latest ENSO wrap released today says conditions in the equatorial Pacific Ocean remain neutral, but return to La Niña towards the end of 2011 cannot be ruled out.

“Trends over the past fortnight include further cooling of the central Pacific Ocean, persistent positive Southern Oscillation Index (SOI) values and stronger than normal trade winds.

“However, cloud patterns are currently close to normal, and all indicators remain well short of the strong La Niña conditions evident at the same time last year.

The bureau said the majority of international climate model forecasts of ENSO (a multi-faceted measure of the oscillation between El Nino and La Nina conditions) are currently predicting neutral conditions into the southern spring.

“While no models suggest El Niño conditions are likely, half of the models predict further cooling over the coming season and into the southern summer.

“It’s worth noting that since 1900, about half of all La Niña events re-emerged in the second year.

“Further cooling of the central Pacific Ocean coupled with persistent positive SOI values in the next few months would further increase the chance of a La Niña event at the end of 2011. “