More cyclones likely around Aotearoa this summer

Te Whanganui-a-Tara - New Zealand may see more cyclones than normal this summer.

The coming cyclone season is forecast to be near or slightly above average, with a range of nine to 12 named cyclones expected to occur in the southwest Pacific between November and April.

At least three of these cyclones may be severe, reaching category three or higher. For New Zealand, which is typically affected by one ex-tropical cyclone on average, the risk of impacts from an ex-tropical cyclone is elevated compared to normal, according to the MetService.

New Zealand’s official Tropical Cyclone Warning Centre works alongside NIWA, Australia’s Bureau of Meteorology and national meteorological services from other Pacific nations to produce a tropical cyclone outlook for the coming season.

MetService will begin to issue its daily tropical cyclone potential bulletin from November 1, or earlier if there is a pre-season development. The bulletin gives a five-day outlook on its website.

This coming season, the El Niño southern oscillation cycle is expected to be in the cool La Niña phase but is likely to weaken and trend towards neutral late in the season.

During La Niña, cyclone activity is more likely in the west of basin, in and around the Coral Sea, especially late in the season from February to April.

All communities throughout the South Pacific, including New Zealand, are encouraged to prepare for the coming cyclone season and remain vigilant for developing cyclones or other severe weather.

It does not take a direct hit or a severe cyclone to cause significant damage or life-threatening weather. If severe weather is forecast, we urge the public to follow official advice from national meteorological services, disaster management offices or local civil defence.

Sometimes an ex-tropical cyclone will approach and may even cross New Zealand.

Memorable examples of ex-tropical cyclones over New Zealand include cyclone Fehi and Gita in 2018 that brought severe weather along with storm surge and coastal inundation to parts of the country.

If cyclones are expected to impact New Zealand with severe weather, official advice will be provided via the MetService. Even if land areas are not affected, warnings are still issued for vessels over the open sea.