The Southwest Pacific is anticipated to experience a reduced or standard number of tropical cyclones this season, according to New Zealand’s National Institute of Water and Atmospheric Research (NIWA) and Metservice.
The cyclone season, which begins in November and runs until April 30, may see between six to ten cyclones, with nine being the average, as predicted by NIWA Meteorologist Ben Noll.
Noll noted that while the total number might be below long-term averages, severe impacts can occur even without a high number of severe tropical cyclones. The cyclone outlook report from NIWA indicates a greater risk of cyclones forming in the western areas of the Pacific due to a developing La Niña, which causes warmer ocean temperatures in that region.
Countries such as Papua New Guinea, Solomon Islands, Vanuatu, New Caledonia, and regions toward Queensland, Australia, are advised to maintain a heightened awareness for cyclones this season, as these areas could experience multiple tropical cyclones.
In contrast, eastern Fiji may have a normal to reduced chance of tropical cyclones, according to Noll, who emphasized that even in seasons with fewer predicted storms, impacts can still be significant.
The report also indicated that historical analogues suggest that several tropical cyclones could reach category 3 strength or higher, with some potentially escalating to category 5, characterized by sustained winds of 200 km/h or more.
Noll highlighted that between three and four severe tropical cyclones at category 3 or above might arise anywhere across the region, urging communities to stay prepared.
Last year, cyclone Lola marked a record as the strongest off-season tropical cyclone in the Southern Hemisphere, achieving category five strength with wind speeds reaching up to 215 km/h, a phenomenon likely linked to the preceding El Niño event.
This year, with the establishment of La Niña, Noll suggested that the cyclone season’s onset may be slower, especially in the eastern basin, where activity typically amplifies later in the season.
He pointed out that conditions in the South Pacific differ from those in the Atlantic during hurricane season, with the South Pacific showing a long-term trend of fewer tropical cyclones. The average number has declined from ten to nine over the past 30 years, a trend that aligns with climate change studies indicating fewer but potentially more intense storms.
Despite forecasts suggesting high cyclone activity during last season’s El Niño, only seven cyclones formed, which is below the long-term average. Noll mentioned that this unusual outcome might relate to the broader context of El Niño effects.
Typically, Vanuatu and New Caledonia see the highest number of cyclones, averaging two to three each year. This season, both regions are expected to have near-normal cyclone activity.