Forecasters say a potentially "super" El Nino is rapidly taking shape in the Pacific -- but whether it evolves into a history-making event could hinge on fickle winds and other volatile atmospheric shifts.The fast-warming tropical Pacific is pointing to a major event but a crucial weakening of trade winds -- capable of turbocharging or throttling the phenomenon -- has yet to materialise.

Scientists say these interactions are notoriously complex and difficult to predict -- making it too early to confidently forecast how powerful this El Nino could become.

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The US National Oceanic and Atmospheric Administration (NOAA) says there is about an 80 percent chance of El Nino developing by July.

Sea temperatures in key El Nino zones of the equatorial Pacific are rapidly rising, and an enormous pool of abnormally warm water is massing beneath the surface.