Live: Tornados strike coastal town, Auckland Harbour Bridge under severe wind watch, could be fully closed

Massive snowfall in Glenorchy. Video / George Heard

A wild winter storm - with heavy rain, snow and isolated tornados - is set to intensify and spread further across New Zealand today, with dozens of warnings in place.

Aucklanders are being warned to expect a wild Monday morning commute as more severe weather is forecast to lash the country - officials are also warning of the possible full closure of the Auckland Harbour Bridge.

The grim forecast follows a wild weekend of weather, including at least two small tornados at Waikanae Beach on the Kapiti Coast, flooding in the Wellington regions and heavy snowfall to parts of the South Island.

There were more than 21,500 lightning strikes over land and water in 12 hours yesterday, MetService said.

There were 41 warnings and watches across the country last night - 18 across the North Island and 23 on the South Island.

Severe thunderstorm warnings were issued by MetService for Wellington city, Porirua, Hutt City, Upper Hutt, Kapiti Coast, South Wairarapa, Taranaki and up the West Coast beyond Raglan, and extending south across a choppy Cook Strait to Marlborough, Nelson, Buller and the Canterbury high country.

Waka Kotahi NZTA is advising motorists of potential disruptions to Monday morning travel in Auckland, and Auckland Transport also said there could be delays or cancellations to public transport today.

The agency said there was a severe wind watch in place for the Auckland Harbour Bridge and a severe thunderstorm watch for the region.

MetService forecasts wind gusts could reach 80-100km/h until 10pm tonight. .

Waka Kotahi said this could result in speed restrictions, lane closures or potentially a full bridge closure.

Drivers of high-sided vehicles and motorcyclists are being encouraged to avoid the harbour bridge while wind warnings are in place, and use State Highways 16 and 18.

Maintenance crews will be out on the Auckland transport network ready to react to adverse weather conditions and close lanes on the bridge if wind gusts exceed threshold levels, Waka Kotahi said.

"Should a full closure of the bridge for safety reasons be necessary on Monday morning, significant congestion can be expected across the network," the agency warned.

"In that event, motorists should expect long delays and avoid non-essential travel."

Motorists are urged to drive to the conditions, look out for the electronic message boards which will indicate lane closures and reduced speeds, and stay within their lane while travelling across the bridge.

Travellers are also advised to plan ahead by checking the Waka Kotahi journey planner website or its Twitter account.

Kapiti Coast tornados

Two small tornadoes have reportedly stormed through Waikanae Beach, Kapiti Coast, on Sunday evening.

Reports on social media suggest windows and doors have been blown in, with uprooted trees and damaged cars.

One local wrote on social media that their trampoline was now gone and that the experience was 'f*****' scary".

The first tornado was spotted around 4pm – while another was reported to emergency services just after 7pm.

MetService duty forecaster Gerard Bellam said heavy rainfall in the area – with 20mm an hour between 4pm and 6pm, and another 16mm between 6pm and 7pm – could produce that sort of weather activity.

"There is a line of active thunderstorms crossing that area at the moment," he said.