No planes are being allowed to land at Auckland Airport and power is out across the city as powerful winds struck.
All flights into Auckland Airport are being diverted because of debris on the main runway caused by strong winds.
The airport said flights were either being returned to their originating airport or Christchurch.
There is no estimated time for when the runway will reopen, it said.
MetService said the winds have eased but would remain strong overnight in Auckland, Coromandel and Waikato.
Civil Defence said it was not activating or mobilising but were standing by to monitor the response.
Hugely violent winds in Mt Albert. Neighbor has lost most of their roof in. Huge chunks of it have gone through my fence and landed in the drive. More to come by the sounds of it. @WeatherWatchNZ @NZStuff pic.twitter.com/cXuaRhXgvh— JonARNZ (@JonARNZ) April 10, 2018
Check out Auckland Airport's website for up-to-date information
A large tree came down across two lanes of New North Road in Morningside, hitting a car.
There was no sign of emergency services at the scene to divert traffic around it, an RNZ reporter on the scene said.
Two houses were hit by falling trees, which smashed through roofs in Stanley Point and Birkdale. Trees also toppled onto a house in Massey and power lines are down on the West Coast Road.
I just watched a good portion of Mt. Eden’s power transformers blow up spectacularly! #Auckland— Paul C (@pacificbro) April 10, 2018
Power is out to many parts of New Zealand's biggest city after sustained winds of 100km/h winds battered the area.
MetService said a 133km/h gust of wind has been recorded at Auckland Harbour bridge.
Niwa said the wind gusts around Auckland this evening were the same strength as a category one cyclone.
Mangere had gusts of more than 100km/h for three consecutive hours - between 8pm and 11pm.
Niwa said winds of this magnitude were typical of category one cyclone intensity.
Power company Vector said there were widespread outages affecting the central city and many western suburbs, with about 15,000 people without power.
In some areas where power is out, there are no street lights and some traffic lights are also out.
Goddamn, riding over the harbour bridge to the shore just now was hands down the scariest thing I've ever done in my life. 30kph, hazards on, being blown from one lane to the other. Lightning strike kills the lights halfway across.— Nathan Palairet (@PalairetNathan) April 10, 2018
Vector said flashes of light reported were from powerlines and power transformers not thunderstorms.
Vector, which covers Auckland and wider city, has 25 outages, mainly in the west and south of the city.
Further south, power company Counties Power, which covers Pukekohe to the west coast and Port Waikato, said there were power lines down and many people face a night without electricity.
Hope you're all ok out there #Auckland, high winds are causing chaos across the region, particularly out west. Remember, if your property is severely damaged or you're in danger phone 111. Trees down on public land can be reported to @AklCouncil on 09 301 0101.— Auckland CDEM (@AucklandCDEM) April 10, 2018
More rain and wind coming elsewhere
MetService said the heaviest rain tonight and into tomorrow would fall in Hawke's Bay where up to 120mm could accumulate.
It said Taranaki, Taihape, and Whanganui would also get a dousing of up to 100mm as well as isolated thunderstorms.
Severe gales are expected in Marlborough Sounds, Wellington, Kāpiti Coast and Horowhenua, Taranaki, Waikato, Auckland and the Coromandel Peninsula, but warnings for in Westland and Buller have been lifted.
Heavy snow has eased about the Kaikōura Ranges and this warning has now also been lifted.
The Transport Agency has urged drivers to be prepared for winter-like conditions on central and lower North Island roads over the next 24 hours.
MetService said there would likely be some snow on the alpine passes overnight.
Follow RNZ's full coverage of the autumn storm here:
- Recap blog: Storm wreaks havoc across the country
- Storm chaos: 'The house is almost completely blown over'
- Tornadoes severely damage North Island homes
- Region by region: What you need to know about the storm
- 'Very unusual': April snowfall surprises southerners
Do you have any weather photos or videos to share? Send them to us: email@example.com
Tornado renders 11 homes uninhabitable in Taranaki
Further south, about a dozen homes in the Taranaki town of Rahotu have lost their roofs, farm buildings were destroyed and power lines came down.
Seven families have had to be relocated.
More than 1000 homes in Taranaki are expected to be without power overnight, but that number could rise if conditions get worse.
Duty controller Brent Manning said people should stay home and not travel unless it was an emergency.
8:35pm #Update: The centre of a low is making landfall in the western North Island (Waikato to South Auckland). Much cooler S to SW winds develop tonight behind the centre spreading over northern NZ. Winds peak between now and the early hours of Weds AM at this stage. pic.twitter.com/EmnrmaXY2s— WeatherWatch.co.nz (@WeatherWatchNZ) April 10, 2018
Meanwhile, 11 homes have been deemed uninhabitable after a tornado struck National Park Village in the central North Island this morning.
The tornado went through the village this morning ripping off roofs and severely damaging homes.
Ruapehu District Council said Urban Search and Rescue have done structural inspections of damaged properties.
Seven have been red-stickered, six have been yellow stickered with 11 properties deemed uninhabitable.
Power has been restored to all properties, damaged properties have had their electricity isolated.
Forty homes remain inside a cordon and residents would not be allowed back home tonight.
Council chief executive Clive Manley said only three of the properties were full-time homes while the rest were holiday homes.
"We believe no one is in danger, all of the buildings with severe damage are cordoned off so people can't enter them.
"Anyone who has any issues or needs tonight can go to the welfare centre which has been set up at the primary school," he said.
Security patrols would monitor the cordons, Mr Manley said.
"In the morning people will be allowed into their properties under supervision, we understand some property owners are driving to the village tonight, we ask that they all just report to the welfare centre," Mr Manley said.
The council's building team will be on site tomorrow morning to post notices on restricted buildings.
Water is safe to drink in the village and sewerage is operational.
Meanwhile, in the West Coast of the South Island, power is out to hundreds of homes in Buller.
Buller Electricity said about 315 households in Karamea and Little Wanganui had lost power, probably due to fallen trees in the Karamea Bluff area.
Tasman police said three camper vans and one caravan toppled near Hokitika, Mount Hercules, Harihari and Westport this morning due the high winds.
Mr Koefoed said roofs had also been lifted in both Westport and Greymouth. He said people should avoid travel and secure trampolines and outdoor furniture.