By Colin Packham
SYDNEY, May 5 (Reuters) - A spike in Pacific Ocean sea temperatures and the rapid movement of warm water eastwards have increased concerns that an El Nino weather pattern this year could be one of the strongest in several decades, an Australian climate scientist said.
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.
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 Organisation, 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."
He based his conclusions on studying data released by the U.S. National Oceanic and Atmospheric Administration.
Meteorologists say the prospect of an El Nino will likely be firmed up in the next month or two, although forecasting the strength of such a weather event is hard to do.
The chance of an El Nino developing in 2014 exceeded 70 percent, Australia's Bureau of Meteorology said on April 8.
Australia's weather bureau will issue is next El Nino outlook report on Tuesday, while Japan's meteorological agency is expected to updated its forecast in the next couple of weeks.
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.
A strong El Nino will also increase fears that production of many key agricultural commodities in Asia and Australia will suffer. (Editing by Ed Davies)