Australia maintained an El Nino alert as indicators of the event, which can bring drought to the Asia-Pacific region and heavier-than-usual rains to South America, begin to emerge before the pattern develops in coming months.
Climate models indicate the weather event is likely to develop by spring, which starts in September, and there’s a 70 percent chance of the pattern this year, the Bureau of Meteorology said on its website today. There’s a 60 percent chance El Nino will set in by the end of August, the United Nations said June 26.
El Ninos can roil agricultural markets worldwide as farmers contend with drought or too much rain. Goldman Sachs Group Inc. says disruptions associated with El Ninos have been most important for cocoa, coffee, sugar and palm oil. India, the world’s second-biggest rice, sugar and cotton grower, recorded the lowest June rainfall since 2009 as forecasters from the U.S. to the UN’s World Meteorological Organization warn the event may happen this year.
“While the tropical Pacific Ocean surface temperature is currently at levels typically associated with a weak El Nino, waters below the surface have cooled and atmospheric patterns continue to remain neutral,” the bureau said. A drop in the Southern Oscillation Index and weakening trade winds “would need to persist for several weeks in order for an El Nino to be considered established, and it remains possible they are simply related to shorter term weather variability,” it said.
El Ninos, caused by the periodic warming of the tropical Pacific, occur every two to seven years and are associated with warmer-than-average years. The last El Nino was from 2009 to 2010, and since then the Pacific has either been in its cooler state, called La Nina, or neutral.
The Southern Oscillation Index, which indicates the development and intensity of El Nino or La Nina events, fell to neutral values over the past two weeks, the weather bureau said. If westerly winds continue, they could drive further warming of surface waters in the central and eastern Pacific, and may be a sign that the atmosphere could be falling into alignment with the signs of a developing El Nino, it said.