1News meteorologist Daniel Corbett explains the impact the approaching tropical storm will have on New Zealand.
It has been a a quiet tropical cyclone season and then, all of a sudden, bang! - Tropical Cyclone Vaianu has barrelled in.
How 'quite nasty' Cyclone Vaianu is tracking as it approaches NZ - watch on TVNZ+
What can we expect this weekend?
This could be one of more intense storms to hit the country for many in a while.
Vaianu developed earlier this week just west of Vanuatu and quickly spun up to a Category 3 with wind gusts over 180kmh.
There's increasing confidence that the weakening tropical cyclone could hit somewhere in the upper North Island over the weekend. Currently, it looks like the landfall of the low centre could cross somewhere between Northland and the Bay of Plenty during the day on Sunday.
More on the details of that in a moment.
NEMA's Director of Civil Defence Emergency Management John Price outlined some of the 'critical' impacts, and urged people not to be complacent. (Source: Breakfast)
But it's almost the end of the cyclone season
The 2025-26 tropical cyclone season had been unusually quiet. That all changed with an active phase in the tropics that helped ignite cyclones Maile and Vaianu.
Up until this point, there had only been two named cyclones all season with Tropical Cyclone Narelle the second of them in late March. Much of the summer went by without a single named storm.
This has been slightly curious given there was a slightly increased risk of tropical cyclone development as a result of a weak La Nina and very warm seas across the Coral Sea and Southwest Pacific.
We did though have some notable tropical rainmakers that affected parts of New Zealand in late January and February. These brought extensive flooding to many areas from Northland to Coromandel and Bay of Plenty, and even down to Banks Peninsula in the South Island.
Curiously, the two tropical rainmakers that hit the country during the summer in previous years could have been tropical cyclones, but upper steering winds and the jet stream position prevented cyclone development.
These storms instead just remained as broad tropical rainmakers that still had loads of tropical moisture but a wider wind field.
Those steering winds, the position of the jet streams and warmer air in the upper atmosphere are all playing a big part in how Vaianu has developed and where it will eventually make landfall in New Zealand.
The big upper ridge in the atmosphere to the east of Vaianu has acted like a brick wall keeping the cyclone from tracking too far east. Instead, it has meant it is making more of a beeline for the north of the country.
Added impact of coastal inundation
It could be a rough one for many of us, who could see significant, and potentially life-threatening, conditions at times over the weekend.
The added risk on this storm will be the increased waves and swell, combined with high tide and lower pressure.
The side of the storm to the right of the eventual track will be most at risk for this.
Add in a high tide and that could be perfect conditions for coastal inundation, flooding and erosion. Then layer on torrential downpours and damaging winds and many northern and eastern coasts of the country will no doubt be preparing for an onslaught.
Stay safe.
Cyclone Vaianu could be a threat to life - watch on TVNZ+
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