Conversely, the Eastern Pacific including countries such as Kiribati, Nauru, Northern Cook Islands and Tuvalu would have the opposite effects, with higher rainfall likely to lead to flooding, damage to roads and bridges, and pollution of water sources.
The alert was released this month by the Secretariat of the Pacific Regional Environmental Programme (SPREP), a regional body for the protection and sustainable development of the region's natural resources. Twenty-two Pacific nations are members.
Mr Philip Malsale, SPREP's COSPPac Climatology Officer, says that there is now twice the normal likelihood of El Niño happening. Five of eight surveyed models indicated El Niño is likely to form by the third quarter of 2017.
"The Pacific has experienced El Niño before, and individual countries need to start planning for possible El Niño event later this year," said Mr Malsale.
"We will continue to monitor the situation and provide additional information in the coming months."
The onset of El Niño is gradual which can result in gradual impacts. The effects are different for each country and appropriate planning needs to be undertaken.
SPREP has informed the climate officers of the National Meteorological Services of potential risks and residents should contact their local authorities for advice.
Photo file: Drought in the PNG Highlands