Latest climate indicators show the ongoing El Nino event continues to weaken and should fade completely by the end of next month, the Bureau of Meteorology says. 

The update says four out of seven climate models indicate sea surface temperatures in the central tropical Pacific are expected to return to neutral El Nino–Southern Oscillation (ENSO), meaning it’s neither in an El Nino or La Nina phase. 

All models indicate a neutral ENSO in May, the update says. ENSO describes the oscillation between the El Nino phase and the La Nina, or opposite, phase. A neutral phase usually means the warmest waters in the equatorial Pacific build up to the north of Australia and that area becomes the focus for cloudiness and rainfall.

“El Nino continues and is near its end. Atmospheric indicators are consistent with a decaying El Nino,” the weather bureau’s Climate Driver Update released yesterday said, adding “international climate models suggest the central tropical Pacific Ocean will continue to cool in the coming months”. 

The bureau declared last September the El Nino was underway but the climate event, which usually brings abnormally hot and dry weather, has not resulted in scorching conditions. It has resembled a La Nina, the rain-inducing event, because other climate drivers that bring about cooler, wet weather were active. 

However, the bureau says it is too early to say a La Nina is on the cards later this year despite three out of seven international climate models suggesting the event will emerge by late winter in the southern hemisphere. 

It says predictions made in early autumn tend to have lower accuracy than forecasts made at other times of the year. 

“This means that current forecasts of the ENSO state beyond May should be used with caution. ENSO forecasts have historically had their lowest skill for forecasts issued in April, with skill increasing from May.” 

However, Australian National University’s Mark Howden says there are “very strong” indications that a La Nina is forming. 

“The sea surface temperatures adjacent to Peru are falling rapidly and there is a large pool of sub-surface cold water developing in the eastern Pacific,” Professor Howden, who is the university’s Director of the Institute for Climate, Energy & Disaster Solutions, told insuranceNEWS.com.au. 

“If it does form, it will build on already anomalously warm oceans around eastern Australia and to our north and this indicates to me a high probability of wetter than average conditions across eastern and northern Australia later this year, along with increased likelihood of cyclones including those tracking further south than usual in addition to increased risk from storms and rain depressions leading to increased flood risk.”