Thunderstorm watch lifted following electrical storms overnight

A thunderstorm watch has been lifted after violent electrical storms pounded Auckland overnight leaving many without power for hours.

Deafening thunder and brilliant lightning woke many in west and north Auckland early today as a brief but fierce storm battered the city.

Some reported the booming thunder as the worst they had ever experienced with
homes shaking after each clap.

MetService said between 6pm and 6am there were 161 lightning strikes across the North Island with 68 in Auckland.

More thundery showers were forecast across the north today with a high risk of potentially damaging storms between Northland to northern Waikato.

MetService forecaster Mariken van Laanen said there was a moderate risk of thunderstorms between Taranaki to northern Bay of Plenty.

This morning police were warning motorists travelling in the central North Island to drive carefully with surface flooding and heavy rain creating difficult driving conditions.

Police said the weather was causing particular concern on State Highway 3 between Palmerston North and Whanganui, and on State Highway 1 between Bulls and Hunterville.

AA Traffic has tweeted that SH1 is closed between Queens Street and Bath Street in Levin.

Traffic management was in place due to landslips on SH32 between Tokoroa and Turangi.

The NZ Transport Agency said a temporary speed limit of 30 kmph was this morning in place south of Levin near the Boulton Road intersection due to flooding.

The Fire Service's Central area communications centre this morning said it had not yet received any weather-related call outs.

Firefighters in the Northern commuications area had been called to just one incident where a tree had done minor damage to a roof in Massey.

Pockets of Auckland remained without power this morning as a result of the rough weather.

Vector confirmed about 140 customers were without power in Clevedon, as well as about 30 in Point Chevalier, 26 in Silverdale and 18 in Albany.

Last night nearly 200 homes were left without power north of Auckland after strong winds and rain buffeted the region.

Vector said 182 households in Kaukapakapa and Kumeu had no power at 9.10pm but was back on again by midnight.

Overall, thunderstorms forecast for the upper North Island appeared to be less severe than expected.

Earlier, fresh thunderstorm warnings were issued by MetService for central and northern North Island regions.

North Shore resident Karen Dallas was woken by the violent storm clap so loud it shook the house.

"Huge thunder storm in progress - Beach Haven Auckland. Thunder woke up the household with shaking lasting seconds. Don't remember experiencing anything like it before!" she posted on Facebook.

Last night severe thunderstorms were moving towards the east of the upper North Island and were expected to lie near Orewa, Inner Hauraki Gulf and Whangaparoa at around 8.30pm, spreading further by 9pm.

Warnings for the Far North, Whangarei and Kaipara were also in place at 8pm.

These thunderstorms were expected to be accompanied by very heavy rain, large hail and damaging wind gusts, MetService said.

Auckland dodges weather bomb

Weatherwatch analyst Philip Duncan said isolated thunderstorms hit around 7pm in parts of Northland, but missed Auckland city.

"The front broke apart just as it came onshore, which happens 80 per cent of the time," he said.

"There have been some thunderstorms in northern rural parts of Auckland and really intense downpours, but Auckland city itself didn't really get them.

"But there is still the risk of thunderstorms around Whangaparaoa and the Bombay Hills. There is another wave of rain coming in behind this and there will be more across the night."

He said the cold front now had three cells - one between Kaitaia and Whangarei which was "pretty intense and could be producing pretty strong winds and hail", and two others between Whangarei and Whangaparaoa producing isolated downpours.

"We are talking three downpours pretty much across the entire upper North Island, and apart from that it's just normal showers. I don't believe it was worthy of the news coverage across today at all, although I do understand why that happened given the severe weather warnings," he said.

Flight warning

Air New Zealand warned of possible flight disruptions as predicted storms hit the upper North Island and Christchurch.

"Forecast severe weather throughout much of the upper and central North Island and Christchurch this evening may cause disruption to flights, with flow-on effects possible elsewhere on the network," the airline said just before 6pm.

"Customers booked to travel on Air New Zealand services in impacted parts of the country this evening are advised to check the arrivals and departures page of the Air New Zealand website or to sign up to Air New Zealand travel alerts for up to date flight information.

"If widespread disruption does occur contact centre wait times are likely to be longer than usual so customers are advised to use online channels in the first instance where possible.

"Affected customers who would now like to delay their travel are encouraged to contact the airline at a later date to make these arrangements, rather than calling the contact centre during what's anticipated to be a very busy period."

High winds

The warning came as the MetService forecast thunderstorms and winds of 110km/h or more in the upper North Island west of Tauranga and north of Taranaki.

High wind has already blown down a tree and smashed a dinghy near Taupo. Matthew and Michelle Whitbread-Edwards, who live on a lifestyle block near Whakaipo Bay, northwest of Taupo, said the strong gust of wind brought the tree down on top of their dinghy just after 2pm.

"We heard this big wind come through and then next minute this huge crash," Michelle said.

The gust also took out the power line to the family's water tank. The wind blew though quickly and eased.

"It was really rainy, and all of a sudden there was this wind. There is hardly a breath of wind now and the sun's out," Michelle said.

"It was just this one tree that has come down and smashed our dinghy. We're just glad it wasn't the one [tree] that would have taken our garage down."

MetService meteorologist Tom Adams said the first flashes of lightning had been spotted off the North Island coast, but more were expected to bring thunder and high winds to the northwest corner of the North Island this evening.

"We have a watch out for severe thunderstorms tonight west of Tauranga and north of Taranaki," he said.

"There are already strong winds, and with severe thunderstorms coming through this evening the bands of rain will get progressively worse."

Winds of 110km/h or worse are forecast when the storms strike.

"Wind gusts of this strength can cause structural damage, including trees and power lines, and may make driving hazardous," MetService said.

Vector also warned of possible power cuts and advised people using medical equipment that relies on electricity to be prepared for power disruptions.

"If there is an immediate health threat, contact their health provider or call 111," Vector said in a statement.

Vector said the public should be aware of potential electricity-related hazards strong winds and heavy rain could create.

"Vegetation and debris can blow into lines and can take out power during these kinds of weather events," it said.