Weather: New Zealand 'in risk zone' as tropical cyclone builds near Pacific Islands, could pose threat next week

New Zealand is "in the risk zone" for a tropical cyclone building in the Pacific Islands, Weather Watch has warned.

While it's still too early to tell whether the storm will reach our shores - or indeed whether it will even become a tropical cyclone - early forecasting indicates it could make landfall next week.

As it stands, modelling suggests it could pose a threat to the upper North Island - though forecasters say it could just as easily turn harmlessly into the Tasman Sea or to the east of the country.

"It's like balancing an egg on a roof when these cyclones track southwards towards narrow northern New Zealand," said Weather Watch head forecaster Philip Duncan.

"They usually roll down one side of New Zealand or the other, but every now and then we get a direct hit. The modelling is showing there is still a lot that could change."

It's estimated there's a 30 percent chance of the tropical cyclone hitting New Zealand.
It's estimated there's a 30 percent chance of the tropical cyclone hitting New Zealand. Photo credit: Weather Watch

Fiji's Meteorological Service says the likelihood of a cyclone forming this week is "moderate to high".

It predicts a low-pressure system will "gradually intensify" through Thursday above Port Vila in Vanuatu, before tracking south.

The tropical cyclone is expected to build next week in Vanuatu.
The tropical cyclone is expected to build next week in Vanuatu. Photo credit: Fiji Meteorological Service

Weather Watch says should New Zealand fall victim to a direct hit, it will happen early to mid-next week. The forecaster estimates the probability is about 30 percent, but says it's still uncertain what exactly the impact would be.

"A few days ago the Tasman Sea and South Island looked exposed to the storm, yesterday it was Northland, today some models show it tracking east of New Zealand and missing us entirely," Duncan said.

"In other words, we need more time to lock this in - but it's certainly one to watch."

Weather Watch says even if the weather system tracks to one side of the country, it could produce "life-threatening beach conditions" as the cyclone whips up large waves and choppy seas.