A red severe thunderstorm warning has been issued for the Far North this afternoon, with damaging wind gusts and tornadoes also possible.
MetService issued a red severe warning for the region after its weather radar detected thunderstorms lying from offshore west of Ninety Mile Beach to offshore Kaipara West Coast at 3.37pm.
“This line of severe thunderstorms is moving towards the east-south-east, and is expected to lie from offshore west of Ninety Mile Beach to Tutamoe to offshore Kaipara West Coast at 04.07pm, and from the Maungataniwha Range to Tangiterōria to South Head at 4.37pm,” it said.
“These thunderstorms are expected to be accompanied by damaging wind gusts and possible tornadoes.
“Very strong wind gusts can break branches from trees, damage roofing, and make driving hazardous especially for high-sided vehicles and motorcycles.
“Tornadoes can blow out windows, lift roofs, break large branches off trees, generate dangerous flying debris and blow vehicles off the road.”
The meteorological service said earlier today that a low over the Tasman Sea will move onto the North Island, and the associated active front will cross the upper North Island from late this afternoon.
Auckland, Northland northern Waikato and the Coromandel Peninsula have been assessed as having a low risk of severe thunderstorms late this afternoon and evening, along with potential wind gusts greater than 110km/h.
NZTA said with 100km/h gusts possible, the Auckland Harbour Bridge could be subject to speed reductions or even closure for periods.
MetService also said there is a moderate risk of thunderstorms for Taranaki, northern Taumarunui, Taupō, and the Bay of Plenty northwards.
“This risk eases in western areas at night. These thunderstorms may be accompanied by heavy rain 10 to 25mm/h, hail of 5 to 15mm in diameter and strong wind gusts of 80 to 110 km/h, especially from afternoon. In addition, there is also a low risk of a small tornado, which could occur with or without a thunderstorm.”
It also extended a broader low risk of thunderstorms southwards over inland Gisborne/Tairāwhiti, Taupō, Taihape, western Whanganui, Marlborough Sounds and western parts of the northwest Tasman and Buller districts.
Strong wind watches have been issued for Northland, inland Hawke’s Bay, and southern Fiordland, Southland including Stewart Island, Clutha and Dunedin.
The Northland strong wind watch is in place from 2pm to 10pm today, with a moderate chance of upgrading to a warning.
For inland Hawke’s Bay, the strong wind watch is in place from “about Napier southwards and the Tararua District” from noon Friday until 6pm Saturday.
MetService said there is a “strong chance” the Napier watch will be upgraded to a warning.
The strong wind watch in southern Fiordland, Southland including Stewart Island, Clutha and Dunedin is in place from 2pm Friday to 2pm Saturday.
MetService said those in the impacted areas should prepare their property by securing items which can be picked up by strong winds, and drive cautiously.
Auckland Harbour Bridge could close — NZTA
New Zealand Transport Agency Waka Kotahi advised there is potential for the wind gusts between 4pm and 8pm to trigger a red alert on Auckland Harbour Bridge, which would result in the closure of all lanes.
It advised drivers of high sided vehicles and motorcyclists to avoid the bridge and use the western ring route on SH16 and SH18.
“We don’t take the decision to lower speeds, close lanes or close the bridge lightly. Our priority is the safety of road users and the bridge structure.
“From 8pm to midnight tonight, an amber alert will remain in place with forecast wind gusts of 75-85 km/h. Under an amber alert, speed limits may be reduced and some lanes on the bridge may close.
NZTA said up-to-date information about any restrictions on the bridge can be found on the electronic message boards which indicate lane closures and reduced speeds.