Damage to roads, powerlines after tornado rips through Levin

A woman who was trapped under a tree in Cambridge earlier today has died at the hospital, police say.

The woman was taken to hospital after emergency services were called to Victoria Square Gardens in Cambridge around 10am this morning, where she had been trapped under an 80-year-old Pin Oak tree.

Waipa District Council spokesperson Sally Sheedy said locals had described seeing a series of mini tornados that tore down trees and power lines in the town at around the same time.

The woman's death would be refered to the Coroner, a spokesperson said.

The extreme weather which caused the deadly accident also saw roofs ripped off houses further south in Levin and the Auckland Harbour Bridge closed.

Elsewhere in Cambridge, a large tree had toppled across a house and cars, bringing down power lines.

MetService said there was a moderate risk of severe thunderstorms across the region, which could produce damaging gusts of wind and there was also a slight chance of a small tornado.

In Auckland, the harbour bridge has been closed for a second time due to high winds.

Waka Kotahi confirmed four lanes were closed as gusts were rising again. Two lanes remain available in each direction.

The bridge was also closed for about 30 minutes at 10am.

A tornado or a collapsing thunderstorm?

In Levin, State Highway 1 has reopened and a clean-up is underway after what locals are describing as a "small tornado" ripped through the Horowhenua town, damaging buildings, bringing down trees and power lines and wrecking vegetable crops.

Fire and Emergency said it had had many reports of roofs lifted and Horowhenua's mayor said one person had received minor injuries as a result of breaking glass.

Metservice said it recorded a wind gust of 140km/h in the town this morning and it is asking anyone with footage of the weather event to contact them so it can determine whether it was indeed a tornado, or a thunderstorm collapsing in on itself.

Horowhenua Mayor Bernie Wanden told Midday Report 30 to 50 houses had been damaged.

He said the most significant damage was in the centre of town and the growing area to the southwest had not been too badly affected.

"Our welfare teams are finding accommodation for a number of people at the moment, to get them out of their houses that are probably unliveable," Wanden said.

"From what I've seen, most of the damage is only in certain parts of the house so ... with a good, heavy tarpaulin, they may be able to still remain in there."

Mitre 10 Levin earlier posted on a local Facebook page, offering to deliver free tarpaulins to people whose houses had been damaged.

Reflecting on the fact only one person had sustained minor injuries, Wanden said the town had "got away pretty lucky, to be honest".

Power had been restored to all but a few hundred people in the district, Wanden said.

Police said early this afternoon that SH1 had reopened but urged drivers to exercise caution as there may still be surface flooding and hidden hazards in the area.

Wanden earlier said in a Facebook video that the "mini tornado" had passed through the town from the west, uprooting trees in the park on Victoria Street and causing power outages and damage to buildings.

"Stay safe," he told his constituents. "I hope there isn't too much damage at your properties and just look after yourselves."

He said teams were out trying to clean up the debris and urged people to stay at home if they were able to.

"It may be a day of just staying at home and just hunkering down for a bit."

Levin locals told RNZ the huge wind, which damaged many of the 130-year-old oak trees lining Levin Adventure Park, hit with a roar around 6.15am.

A dairy owner on the main street said a woman driving through narrowly escaped being crushed by falling trees blocking her truck.

The main street and several other suburban roads are cordoned off while fire-fighters and emergency management personnel assess the damage and make urgent repairs.

Kelly Fox, who runs the Traffic Updates Horowhenua Kapiti Wellington Facebook page, said power lines had fallen on a car in Mako Mako Rd and some roofing iron ended up on the tracks in Levin.

In addition, the district council said power lines were either down or damaged on Parker Avenue, Victoria Street, Tawa Street, George Street, Adkin Avenue, Skye Street and Cambridge Place.

Oxford Street, Cambridge Street (from Liverpool to Bath Street), Tawa Street, Wilton Street, Gladstone Road, Winchester Street, Tararua Road, Parker Street and Sterling Street were closed this morning.

A school in the town ended up with a neighbour's garage on its property after the weather event struck.

St Joseph's Catholic School principal Maria Lyne said the playground was "obliterated", a large piece of iron was wrapped around the rugby goal post and the school's trampoline was destroyed.

Civil Defence had been called in to help emergency services throughout Levin, and it urged people to stay home unless travel was critical.

Fire and Emergency had activated an urban search and rescue team, which would work alongside the district council's building team to prioritise assessment along all the roads and streets that had received damage or were closed.

The Palmerston North City Council Rescue Emergency Support team had been deployed to assist and Rangitikei District Council had offered assistance to capture drone footage, to understand the extent of the damage.

Several schools in the area were closed while damage was being assessed; St Joseph's School, Learning Adventures, Levin School, Levin Intermediate School, Horowhenua College and Ōhau School.

Horowhenua District Council also advised that water treatment plants at Shannon and Tokomaru were currently offline due to turbidity. Water storage capacity was sufficient, the council said, but as a precaution tankers had been activated for Tokomaru.

Hail storm destroys crops

In Ōhau, just south of Levin, long time grower Gordon Sue said his sons Nigel and Travis were out in the field when the wind hit and tore the plastic off the giant greenhouse, flattening their seedlings.

"I woke up to this banging on the roof, I thought it was cats! But it was hail stones."

Many crops have been damaged by hail.

Sue said it has set them back at least three months.

"It is going to mean higher prices for vegetables."

Another local grower, Jay Clarke, told RNZ the damage at his Woodhaven Gardens was "catastrophic".

"I think we're looking at the worst hail damage that we've seen in 44 years of growing in the district."

The silverbeet and cabbage crops looked as if someone had shot a machine gun at the plants, he said.

MetService said there were at least 4297 lightning strikes around New Zealand and the Tasman Sea in the eight hours since midnight.

NIWA warns of more to come for west of North Island

National Institute of Water and Atmospheric Research (NIWA) is warning strong winds similar to those that hit Levin are expected along the entire west coast of the North Island this afternoon.

Meteorologist Ben Noll said the winds would potentially be damaging, with gusts of up to 80km/h.

"Certainly, any loose items outdoors, folks'll want to make sure they either bring them inside or take them down," he said.

Heavy showers and some hail were also expected and road snowfall warnings have been issued for the Desert Road in the North Island.

In the South Island, temperatures are expected to fall and snow is forecast for higher elevations, particularly on the Crown Range and the Milford Road.

Noll said the worst of the storm would pass over the country today.

MetService said there had been 12,000 lightning strikes in the six hours between half past five and half past eleven this morning.

Big hail, squally winds and downpours had also affected some areas.