The tropical Pacific is showing signs of a developing El Nino with ocean temperatures exceeding thresholds for the weather pattern that can bring drought to parts of Asia and rains to South America.
Sea-surface temperatures have surpassed thresholds and trade winds have been weaker average for several weeks, Australia’s Bureau of Meteorology said on its website Tuesday. If these patterns persist or strengthen, El Nino will become established, it said.
Australia had raised the possibility of an El Nino for most of 2014 before tempering its forecasts. The U.S. Climate Prediction Center has said that a weak El Nino developed in February and there’s a 70 percent chance the pattern will continue through the Northern Hemisphere summer. The Australian forecaster said on April 14 that the ocean was primed for an El Nino and thresholds may be reached or exceeded by June.
“Ocean temperatures are likely to remain above El Nino thresholds until at least the southern hemisphere spring,” the bureau said. The forecaster kept its alert, indicating triple the normal chance of El Nino in 2015, it said.
El Ninos, caused by periodic warmings of the equatorial Pacific, can roil world agricultural markets as farmers contend with drought or too much rain.