The National Institute of Water and Atmospheric Research in New Zealand, or NIWA, says an El Nino weather pattern is likely to develop in the Pacific mid-year.
A scientist, Andrew Lorrey, says El Nino occurs every three to seven years, and there are some indications that this year's could be a particularly strong event.
Dr Lorrey says during El Nino, the South Pacific Convergence Zone rainband shifts north of where it usually sits, which can result in changes in rainfall patterns, sea-surface temperature and tropical cyclone occurences.
"Some of those countries might see unseasonably high rainfall, which normally sit to the north of the SPCZ, that rainband. And in addition to that, we typically see tropical cyclone activity increase for countries east to the dateline in El Nino years."
Andrew Lorrey says because of changes in sea levels, alternative routes in and out of small lagoons may need to be planned.
He says it is monitoring how things are developing in the equatorial region over the next few months to predict likelihood and impacts of a strong El Nino.