The El Nino event in the Pacific Ocean continues to weaken and conditions are expected to return to neutral in April or May, the Bureau of Meteorology says. 

“Sea surface temperatures in the central tropical Pacific and temperatures in the Pacific sub-surface show a clear cooling trend, in line with typical event decay,” the bureau said.  

Atmospheric indicators have been more mixed, but fluctuations are often seen during summer. 

Records since 1900 show 50% of El Nino events have been followed by a neutral year, and 40-50% have been followed by a La Nina, which is associated with higher rainfall and increased flood risk over much of Australia. 

But the bureau says global oceans have warmed significantly over the past 50 years and were the warmest on record globally between April last year and January, which may affect outlooks. 

Predictions made in late summer and autumn for the El Nino Southern Oscillation (ENSO), which describes swings between El Nino and La Nina phases, tend to have lower accuracy than those made at other times of year.

“This means that current forecasts of the ENSO state beyond May should be used with caution,” the bureau said.