A U.S. weather forecaster said on Thursday the chances that the much-feared El Nino phenomenon that can wreak havoc on global crops would strike by the Northern Hemisphere summer exceeded 50 percent.
The U.S. outlook raises the prospect of damaging floods and droughts across the globe and came after Australia's Bureau of Meteorology on Tuesday pegged the chances of El Nino in 2014 at more than 70 percent.
Global cocoa prices have rallied to 2-1/2-year highs on worries El Nino could return in 2014, while other agricultural commodity markets could also be hit by the specter of the weather anomaly.
El Nino - a warming of sea-surface temperatures in the Pacific - affects wind patterns and can trigger both floods and drought in different parts of the globe, curbing food supply.
The worst El Nino on record in 1997/98 was blamed for massive flooding along China's Yangtze river that killed more than 1,500 people.
Below are some of the key commodities that could be affected by its return.
Grains, Oilseeds, Livestock
El Nino could bring dry weather to Australia, which is already struggling with a drought that has forced ranchers in the world's third-biggest beef exporter to cull cows, raising fears of a global beef shortage. El Nino could also curb wheat, sugar and cotton production in the country.
It could also hurt crops in Thailand, one of the world's largest rice exporters, potentially worsening drought conditions usually seen in March-April.
El Nino would bring milder-than-normal temperatures to the major crop production areas of the U.S. Midwest. Iowa and Minnesota would benefit from the event's tendency for wetter-than-normal summers as the western Corn Belt continues to recover from a drought.
But excessive rains in the saturated soils of the eastern Corn Belt could be troublesome, particularly following this year's overly snowy winter. Drought-hit California, a major dairy and wine grape state, could see more rain than normal.
In China, El Nino could bring more rain to areas south of the Yellow River and cause flooding in the country's major rice and cotton growing regions.
Lower-than-normal temperatures could also occur in the country's top corn and soy areas in the northeast, leading to frost damage and lower grain output.