A new blast of strong windy and wintry weather is forecast to strike today, with Aucklanders urged to take care driving and prepare for possible power outages.
Snow hit the bottom of the South Island today, forcing the closure of major highways and several schools.
The winter-like surge will track into the North Island this morning – with Auckland in the firing line for a southwest shift from the afternoon.
A strong wind watch is in place for Northland from Whangārei southwards, Auckland, Great Barrier Island, and Coromandel Peninsula north of Hot Water Beach from 4pm today. MetService is warning wind may approach “severe gales” in some places.
Active & turbulent weather for the North Island today.
— NIWA Weather (@NiwaWeather) September 16, 2024
For some, wind gusts are forecast reach near, and possibly exceed, 100 km/h (🔴).
The strongest gusts will likely occur with squally showers & thunderstorms (some with hail).
Pockets of power cuts & damage possible. pic.twitter.com/TiZtA3A9Ap
Meanwhile, farther south, a section of Lindis Pass (SH8) has been closed due to snow and ice. The New Zealand Transport Agency said SH73 Springfield to Castle Hill (Porters Pass) is open with restrictions and chains “are essential”.
SH93 from Matarua to Clinton is also closed following “heavy snowfall”.
SH93 MATAURA TO CLINTON - SNOW - 7:40AM, TUE 17 SEP
— NZ Transport Agency - Otago & Southland (@nztaos) September 16, 2024
State Highway 93 is now CLOSED between Mataura and Clinton townships, following heavy snowfall. Avoid the area, consider using State Highway 1 as an alternative route, or delay travel until snow conditions in the area ease. ^CS pic.twitter.com/uZDQMizZme
Invercargill MP Penny Simmonds
Cold temperatures in the upper levels are expected to create unstable conditions, which may lead to showers and thunderstorms in parts of the North Island.
“It’s going to be a pretty bleak day for Aucklanders. Temperatures are not forecast to get above the 14C mark and that southwest wind is going to be noticeable,” MetService forecaster Lewis Ferris said.
In the South Island, Alexandra, Wānaka and Queenstown residents are waking up to negative temperatures, some as low as -3C. The bottom of the North Island is also close to freezing temperatures, with Wellington dropping to 3C this morning.
In Methven, several school bus services have been cancelled due to the icy conditions.
For coastal Whanganui, Taranaki, Waitomo, Waikato, Auckland, Northland and Coromandel there is a moderate risk of thunderstorms on Tuesday morning, which might be accompanied by heavy rain and small hail.
In the afternoon, there is a moderate risk of thunderstorms in Bay of Plenty, including Rotorua, Gisborne, Taupō and Hawke’s Bay. These storms may continue along the coast of Gisborne and the Mahia Peninsula into the evening, potentially bringing heavy rain (10 to 15mm/h) and small hail.
The NZ Transport Agency is asking motorists using the Auckland Harbour Bridge to take extra care, with strong gusts expected between 9am and 9pm.
SH1 AKL HBR BRIDGE - 6:30AM
— NZ Transport Agency - Auckland & Northland (@nztaaklnth) September 16, 2024
Due to strong wind gusts extra care is currently required on the Harbour Bridge, especially for high-sided vehicles & motorcycles. Please obey speed signs and maintain a safe following distance. ^HJ pic.twitter.com/Vjtd5BDgRY
“These southwest gusts are expected to become more frequent, reaching 90-100km/h through the afternoon and early evening,” the agency said.
It was likely speed limits would have to be lowered, and some lanes on the bridge might also be closed if gusts grew severe enough.
Vector is also warning strong winds could bring power outages, with the areas likely most affected by gusty winds including the west coast, Warkworth and Wellsford.
“Ahead of this, now’s a good time to take necessary precautions such as checking devices are charged, keeping a torch handy, having backup power sources and staying up to date on local weather warnings,” Vector said on Facebook.
“Our crews are monitoring the situation, and are ready to respond to any power outages as quickly and as safely as they can.”
Wellington is also in for a chilly day with gale southerlies and the mercury potentially not even making double digits. Rain could be heavy for a time but it’s forecast to become less widespread as the day progresses.
Here's a unique view of the incoming southerly: the wind arrows are colour-coded to the temperature! 🌬️
— NIWA Weather (@NiwaWeather) September 16, 2024
The winter-like surge will track across the South Island tonight & into the North Island on Tuesday morning.
Tuesday will be a *very cold* day for the time of year 🥶 pic.twitter.com/OYjosqK3x0
MetService has issued multiple road snowfall watches and warnings around New Zealand, including the Napier-Taupō Rd (SH5) and the Desert Rd (SH1), where up to 10cm could fall in areas above 700m.
There is also a road snowfall warning for Remutaka Hill Rd (SH2) where rain could turn to snow above 400m.
In the South Island, road snowfall warnings have been issued for Lewis Pass (SH7), Porters Pass and Arthur’s Pass (SH73).
“Over winter and into September, most of the snow potential has been isolated to the South Island, but this time, with that direct hit of cold air coming from the south and southwest, everyone’s getting a taste of it,” Ferris said.
Snow has begun to fall in Canterbury as residents awake to freezing 3C temperatures.
Aucklanders wouldn’t get any snow themselves, he added, “but they might get some hail on Tuesday”.
MetService said Wednesday would be a “slight easing” in the stormy weather – but that respite would be brief as more rain swept onto the North Island and the west of the South Island on Thursday.
Niwa forecaster Ben Noll said the wintry weather could be described as “the last hurrah” of a rare polar heatwave over Antarctica that had been strengthening low-pressure systems to the south of New Zealand.
But sunnier days were on the cards for the weeks ahead.
“The good news is that high pressure will become much more abundant in the New Zealand region starting next week.”
Niwa has given 50-50 odds of a La Nina climate pattern forming up by end of spring – along with an earlier-than-usual shift to summer-like weather later in the season.
Jamie Morton is a specialist in science and environmental reporting. He joined the Herald in 2011 and writes about everything from conservation and climate change to natural hazards and new technology.
Sign up to The Daily H, a free newsletter curated by our editors and delivered straight to your inbox every weekday.
The heavy rain watch has a moderate chance of becoming a warning.