The Pacific Islands Climate Outlook Forum (PICOF) provides a platform for the review of recent climate, while also looking ahead, detailing information on likely temperature, rainfall and oceanic conditions for the upcoming three to six months in the Pacific region.

The exchange and use of climate information developed during the fourteenth session of the PICOF can be used by National Meteorological and Hydrological Services (NMHS) across the Pacific to inform decision-making at sectoral and community levels.

At PICOF-14, the Pacific Regional Climate Centre Network (RCC-N) members of the lead node on long range forecasting offered insights into potential climatic patterns over the coming months and provided an understanding of what parts of the region might experience significant climatic events, such as reduced rainfall and the potential for drought, prolonged heavy rainfall and extended periods of flooding, and significantly below or above normal tropical cyclone occurrence.

In early April 2024, the Pacific RCC-N El Niño-Southern Oscillation (ENSO) tracker maintained an El Niño event based on status reports from the majority of Pacific RCC-N node on climate monitoring and long-range forecast members, the Australia Bureau of Meteorology (BoM), National Institute of Water and Atmospheric Research (NIWA), and National Oceanic and Atmospheric Administration (NOAA). However, the BoM (since 16 April) reports the El Niño event to be over.

The forum also discussed the return to neutral conditions and the possibility to transitioning into La Niña in the second half of 2024.

El Niño is a major climate driver in the Pacific, which is associated with warmer ocean temperatures in the central and eastern tropical Pacific Ocean as well as an atmospheric response to those changes.

In line with PICOF-13 prediction from October 2023, the El Niño event was associated with above normal rainfall in the Gilbert and northern Line Islands of Kiribati.

Boyd MacKenzie, of the National Weather Service in the Federated States of Micronesia (FSM), reported impacts in the Micronesia region.

He said, “Strong winds were reported in the northern part of the Gilbert group, causing destruction to houses and infrastructure. This El Niño event brought heavy rainfall and coastal flooding affecting people’s movements. The coastal flooding also caused intrusion of salt water into household and community wells also affecting the quality of water sources.”

MacKenzie also commented on large north swells in Kiribati in January 2024 which caused extensive damage to the Kiribati Oil Company Limited seawall, located in the Christmas Islands. He also shared, “In March, a strong trade-wind swell combined with King tides resulted in coastal flooding in Temaiku and Abemama, Kiribati, causing damage and loss of subsistence food crops.”

Similar impacts were observed in the Melanesia and Polynesia sub-groups, where Fiji, Tuvalu, Tokelau, Tonga, and the Solomon Islands reported above average rainfall and flooding events, and tropical cyclones and associated impacts reported around the Solomon Islands.

Below normal rainfall was observed in the Commonwealth of the Northern Marianas (CNMI), most islands of FSM, Marshall Islands, southern Tuvalu, Wallis and Futuna, Samoa, southern Cook Islands, southern, and northern French Polynesia.

This has been evident across countries in the Western Pacific where drought now places a strain on agriculture and access to water.

MacKenzie presented on the climate impacts in FSM noting, “Prolonged drought coupled with swell events have damaged food crops and saltwater intrusion caused contamination of water sources. With this, a State of Emergency was declared nationally, due to the lack of access to fresh drinking water and an increase in disease outbreak.”

Selu Ilolahia of the Tonga Meteorological Service, presenting on the impacts of El Niño in Polynesia, noted a similar occurrence in Tonga.

“According to our rainfall data, we observed drought conditions between October – December 2023. This causing water shortages and in turn affected our crops, driving up the prices of food.”

However, the El Niño also had positive impacts across the Pacific.

Ilolahia highlighted the impact of drier conditions on vanilla production in Tonga, “Vanilla plants generally produce more flowers during drier than normal conditions, and we have seen above normal production in Vava’u and Eua.”

In Kiribati, El Niño resulted in above normal rainfall, allowing the country to recover from a drought in previous years.

Philip Malsale, SPREP Senior Climatologist. Photo: SPREP

Philip Malsale, Senior Climatologist for the Secretariat of the Pacific Regional Environment Programme (SPREP) further explained the El Niño event.

He said, “When it comes to El Niño, no two events are the same. In the region, the 2023-24 El Niño event had a unique oceanic and atmospheric imprint. Compared to the major El Niño events of 1997-98 and 2015-16, the event in 2023-24 featured more rising air over the western Pacific, a La Niña-like trait. This was probably linked to remnant warm water in the western Pacific following a triple-dip La Niña from 2020-2022 and marine heatwave conditions in the Coral Sea and off-equatorial of the Western North Pacific basin and South Pacific.”

A survey conducted at PICOF-14 showed that the NMHS in the region were aware of the atypical impacts of the event. Experiences during this El Niño event can be used to prepare for the next one, particularly as the climate continues to change.

PICOF-14 also informed participants of a possible La Niña in second half of 2024.

Thomas Abinun, a meteorologist from Météo-France New Caledonia, presented on the ENSO status and outlook.

He said, “a return to ENSO neutral conditions is expected from April to June with a La Niña potentially arriving as early as July or August 2024”. A variety of models were considered at PICOF-14 and based on their output, it wasn’t certain that La Niña would return this year.

The NMHS are encouraged to engage monthly to discuss ENSO, climate drivers, and climate outlook during the Ocean and Climate Outlook Forum (OCOF).

This platform provides updated information to inform Pacific communities. Through events like PICOF, members of the Pacific RCC-N will provide the latest climate and ocean science which is used to help inform Pacific communities and prepare them for potential extreme events, variability, and change in the region.