A woman who was trapped under a tree in Cambridge as wild weather sweeps up the North Island has died. 

A police spokesperson confirmed the woman, who suffered critical injuries after being trapped by a falling tree in Cambridge, had died. 

"Police can confirm a woman has died from injuries sustained after being trapped under a tree in Cambridge." 

Meanwhile, motorists in Auckland have been warned to prepare for delays as lane and speed restrictions are in place on the Harbour Bridge because of high winds. 

In Cambridge, locals and residents on Victoria, Queen, Hall, Wilson and Dick streets reported seeing small tornadoes in the area. 

A woman suffered critical injuries when she was crushed by a fallen tree in Cambridge. Photo / Adam Pearse

The local council said "freakishly high winds" ripped a healthy tree out of the ground and the woman was trapped beneath it. 

The woman suffered critical injuries and had to be freed from under the fallen tree by firefighters in Victoria Square. 

The large tree toppled over onto a picnic table. 

Northern Fire and Emergency shift manager Jordan Barnett said a fire appliance and two support vehicles also responded. The person was "removed from the tree" at about 10.50am. 

Police received reports of the incident at 10.04am. 

Harbour Bridge lanes reopen after high winds 

The Harbour Bridge has reopened with lane and speed restrictions in place as NZTA warns motorists to avoid the area this afternoon or expect long delays. 

Four lanes are closed again on the Auckland Harbour Bridge as wild weather concerns continue. 

Earlier today the bridge was briefly closed entirely as wind gusts reached 95km/h. 

'It was devastating'

Richard and Trixie Millet had parked their campervan right in front of the fallen tree, possibly just minutes after it hit the ground. 

At the time the pair were unaware a person – believed to be an elderly woman – was stuck underneath. 

Two trees had fallen but at that stage – around 10am – no emergency services were at the scene and there was no indication someone needed help. 

They walked to a nearby cafe but when Richard returned to the camper, he knew something was wrong by the presence of emergency services staff digging with shovels around the base of the fallen tree, presumably to free the woman. 

"It was devastating that I wasn't aware that someone needed help, that we could have called emergency services earlier," he told the Herald. 

Richard rushed back to the cafe and informed Trixie and the friends they had been meeting. 

"[Richard] came back very pale and shocked," Trixie said. 

Seeing their camper parked near the site, Trixie overheard people's assumptions it had been those in the camper who were in strife. 

Following that, Trixie quickly sent a text to the family, informing them that they were okay. 

The pair said they "felt deeply" for the woman and her family, hoping she would be okay. 

Arriving at the scene, the pair – from Rissington, Hawke's Bay – had been unaware a small tornado had torn through the small town. 

However, they described very strong gusts and squally conditions. 

A woman suffered critical injuries when she was crushed by a fallen tree in Cambridge. Photo / Adam Pearse

Waipa District Council said the tree was felled by "freakishly" high winds. 

The tree was a healthy pin oak that was about 80 years old. It had been pruned at the start of April and there had been no previous concerns about it, council group manager customer and community services Sally Sheedy said. 

"It has been described to me as a mini-tornado which look to have lifted a perfectly healthy tree out of the ground. Our concern and thoughts now are with the person who was trapped and we sincerely thank those who acted so quickly to help." 

Sheedy confirmed there were also reports of at least four more trees down in Hall St. 

Council contractors were at the site and waiting for lines company Waipa Networks to isolate power before the clean up could begin. 

"Those with queries about power supply should contact Waipa Networks directly. In the meantime, we are asking people to avoid the Hall St and Victoria Square areas so we can help deal with the damage," Sheedy said. 

"In the meantime, council staff are now out checking on all other trees and parks in the area. We are urging people to be cautious and safe and to report any concerns to us immediately." 

Earlier: Wind warning forced Auckland Harbour Bridge to close

Auckland Harbour Bridge has reopened after strong wind fears briefly forced all lanes to close as wild weather descends on the city.

Waka Kotahi warned Aucklanders to delay travel or use State Highway 16 via West Auckland, as winds were tipped to hit more than 95km/h.

The Harbour Bridge was temporarily closed as a precaution; some lanes reopened at 10.19am. All lanes were opened again at 10.26m.

Concern at high winds forced the temporary closure of Auckland's Harbour Bridge today. Image / NZTA

The wild weather is ramping up across Auckland as heavy showers, thunderstorms and blustery winds start to batter the region. 

It follows a tornado in Levin early today that carved a trail of destruction, damaging buildings, uprooting trees and closing streets. 

MetService is warning the City of Sails is in the firing line of a fierce band of wet weather this morning that includes lightning and wild winds. 

There is currently a severe thunderstorm watch in store for neighbouring Waikato and a fresh warning of storm-forced winds and small tornadoes. 

The Horowhenua region was left in chaos after a tornado ripped through the western region before dawn this morning. 

MetService earlier warned that severe gales were possible for parts of the country today and across the weekend. Strong wind watches are in force across much of the North Island and parts of the South Island. 

This morning Waka Kotahi issued a fresh warning for vehicles using the Auckland Harbour Bridge warning that strong winds could see lane closures across the day. 

It warned motorists should be prepared for possible lane closures and delays on the bridge between 10am and 7pm and high-sided vehicles and motorcyclists were recommended to use the western ring route instead. 

The unruly weather comes as Mother Nature is set to unleash a full smorgasbord of wintry conditions on New Zealand today with snow, gales and rain forecast for many parts of the country. 

Snow is forecast to fall across most of the South Island as well as parts of the lower and central North Island today and over the weekend. 

MetService has issued road snowfall warnings for Crown Range Rd, Milford Rd, Desert Rd, Lewis Pass and Arthur's Pass for the next 24 hours. 

Snow is expected to drop to 400m in Southland and Otago, 800m in the Canterbury high country and 1000m for the central and southern North Island. 

"This will be the lowest snow many have seen so far this year," MetService said. 

Temperatures have also dropped considerably in the South Island. A high of 12C is expected in Christchurch today, a stark difference from the high of 20C yesterday. 

While temperatures in the upper North Island will stay relatively warm, gale warnings have been issued for Auckland's Hauraki Gulf, Manukau Harbour, Coromandel, Bay of Plenty and Bream Head in Northland to Cape Colville.