El Nino Odds High As Pacific Ocean Warms

By Phoebe Sedgman (Bloomberg) – An El Nino weather pattern, which can parch parts of Australia and Asia while bringing rains to South America, will probably develop in the next few months as the Pacific Ocean warms, Australia’s Bureau of Meteorology says.

The chances of El Nino developing during the southern hemisphere winter are more than 70 percent, the bureau said on its website today. It is too early to determine the strength of the possible weather pattern, it said. Australia’s winter starts in June and runs to the end of August.

El Ninos affect weather worldwide and can roil agricultural markets as farmers contend with drought or too much rain. The phenomenon often touches off warmer winters across the northern U.S., heavier rains from southern Brazil to Argentina and drier conditions across Southeast Asia, Indonesia and eastern Australia. It also can lead to a calmer Atlantic hurricane season and a stormier winter in the U.S. south.

“Surface and sub-surface ocean temperatures have warmed considerably in recent weeks, consistent with a state of rapid transition,” the Melbourne-based bureau said. “Most models predict sea-surface temperatures will reach El Nino thresholds during the coming winter season.”

The pattern would come after this year’s dry spell parched some Brazilian growing areas. Prices for arabica coffee surged 81 percent this year. The S&P GSCI gauge of eight crops climbed 16 percent over the same time.

Southern Oscillation

The Southern Oscillation Index, which indicates the development and intensity of El Nino or La Nina events, was at minus 9, according to the bureau. Sustained negative values below minus 8 may indicate an El Nino event, it said.

The U.S. Climate Prediction Center issued an El Nino watch last month. There’s a 52 percent chance that the Pacific Ocean will warm enough to trigger the pattern late this summer or in early fall, according to climate scientist Michelle L’Heureux. The odds of El Nino emerging later in the northern hemisphere summer are 75 percent, MDA Weather Services said last month.

While the pattern will probably start changing global weather from May, it will begin as a mild to weak event and take many months to meet the definition of an El Nino, Drew Lerner, president at World Weather Inc. said this month. The last El Nino occurred in 2009 to 2010, and since then a cooling called La Nina and a period of neutral conditions have held sway, according to the Climate Prediction Center.

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