A destructive tornado has torn off a roof and left a trail of debris in Greymouth this morning and Aucklanders have been warned that lanes on the Harbour Bridge may close due to high winds later today.

Footage on social media shows the twister sweeping through the West Coast township just after 8.30am, damaging property and sending debris swirling into the air.

At least one home has lost its roof. A sleepout has been lifted off its foundations. The violent wind lasts less than a minute.

It comes as much of central and western New Zealand lies under a swathe of weather alerts, with thunderstorms building in the Tasman Sea.

Waka Kotahi NZTA has warned Auckland commuters that lane closures and speed restrictions may be in place due to high winds.

“It is likely that speed limits may be reduced and some lanes on the bridge may close if wind gusts reach threshold levels,” Waka Kotahi NZTA said in a statement.

“Drivers of high-sided vehicles and motorcyclists are advised to avoid the Auckland Harbour Bridge and use the western ring route on State Highways 16 and 18.”

Severe thunderstorm watches are in place from Waikato to Marlborough until 6pm with MetService warning intense downpours during the electrical storms could see flash flooding, slips and hazardous driving conditions.

Weatherwatch.co.nz says a few thunderstorms are currently building around New Zealand’s western and northern coastline this morning.

Police issued a warning to motorists to avoid Wellington’s Remutaka Hill due to deteriorating weather conditions and an earlier crash.

Waka Kotahi NZTA said: “SH2 Remutaka Hill remains closed between Kaitoke and Featherston, due to strong winds. Please continue avoiding this area and consider delaying your journey”.

Earlier, one lane was closed on the south side near the summit after a truck trailer tipped just after 10am.

A spokesperson said high winds were making it increasingly difficult to travel over the hill.

A strong wind watch is in place for the bottom of the North Island with winds reaching severe gales in exposed places and many central regions lie under a heavy rain watch.

Waves of up to 4m are expected to batter the Wellington coast line overnight.

MetService say it is “an unseasonably cold outbreak” and snow may fall to around 700 metres over the lower South Island tomorrow. 

MetService meteorologist Juliana Bergdolt told the Herald the “quite intense” trough would be moving from the South Island to the North Island today, reaching Auckland tonight. 

Heavy rain watches are in place for the Westland ranges, the headwaters of Canterbury lakes and rivers from Arthur’s Pass southwards, central and western areas of the North Island and the ranges of Eastern Bay of Plenty and Tairāwhiti. 

A strong wind warning is also in effect for the Canterbury High Country, with gusts expected to reach 120km/h in exposed places. 

MetService meteorologist Ngaire Wotherspoon said more warning areas could be added farther north, and existing watches could be upgraded as they gather more information. 

Wellington, Kāpiti and Wairarapa are under a severe thunderstorm watch until 6pm, with weather conditions likely to bring thunderstorms with rainfall rates up to 40mm/h. 

MetService warned that rainfall of this intensity can cause surface and/or flash flooding, especially in low-lying areas such as streams, rivers or narrow valleys and may also lead to slips. 

Driving conditions will also be hazardous, with surface flooding and poor visibility in heavy rain. 

The forecaster said cold, strong southwesterly winds will follow the trough, spreading heavy showers and thunderstorms over southern and central Aotearoa. 

“Hot temperatures occurred in eastern South Island areas over the weekend, so this cold southerly change will be felt keenly over the next couple of days. Alexandra had a high of 29C on Saturday, and by Tuesday they have a forecast high of 14C, and 4C overnight,” Wotherspoon said. 

Large swells generated by strong southerlies are in store for the south and west coasts this afternoon, but will then die out on Tuesday afternoon as the weather system shifts away from Aotearoa. 

Wotherspoon said an end to the wild weather is on the horizon as a ridge of high pressure is to settle over most of the country on Wednesday.