A majority of weather forecasting models indicate that an El Nino may develop around the middle of the year, but it was too early to assess its likely strength, the U.N. World Meteorological Organization said on April 15.
Dr Wenju Cai, a climate expert at Australia's Commonwealth Scientific and Industrial Research Organization, said rises in Pacific Ocean temperature above those seen in previous El Nino years and the quick movement of warm water eastwards had raised fears of a significant event.
"I think this event has lots of characteristics with a strong El Nino," said Cai.
"A strong El Nino appears early and we have seen this event over the last couple of months, which is unusual; the wind that has caused the warming is quite large and there is what we call the pre-conditioned effects, where you must have a lot of heat already in the system to have a big El Nino event."