People living along the south coast of Wellington are encouraged to have a bag packed in case they need to evacuate their homes tomorrow.
Photo: PIXABAY
Powerful waves, strong winds, and snow are forecast for much of the country, as a blast of Antarctic air rolls over Aotearoa in the next few days.
Large swells are forecast, building from tomorrow morning until Wednesday evening, and waves could be as high as six-metres along Wellington's south coast.
Wellington Region Emergency Management's Jeremy Holmes said people should be prepared.
"Basically people living close to swell and surf-exposed coastline should be prepared for the possibility of wave overtopping and flooding, damage to property, the depositing of debris and driftwood, sand and gravel could also make access difficult or dangerous and there could be some possible road closures."
MetService issued a warning for the 41 hours from 6am on Tuesday to 11pm on Wednesday.
The southerly swells were due from Baring Head to Sinclair Head at Ōwhiro Bay, and the biggest risk period was due to be high tides on Tuesday 8.24am and 8.54pm and on Wednesday at 9.18am and 9.48pm. Swells would ease by Wednesday, dropping to around 4 metres.
Interislander sailings for Tuesday have been cancelled, and Wednesday cancellations are likely.
All Bluebridge freight and passenger sailings have been cancelled tomorrow and on Wednesday morning.
The 10.30pm Kaiarahi sailing from Picton on Monday will be the last before the cancellations come into effect, Kiwirail said.
Waves at Ōwhiro Bay on Wellington's south coast (file). Photo: RNZ / Charlotte Cook
"These are very large, high-energy waves, and can catch people unawares if they're walking on beaches or driving along coastal roads. There's also the potential for waves to affect land or property near coasts, MetService meteorologist Alwyn Bakker said
The winds driving the swell are also a potential risk, MetService said. Exposed places on the south and east coasts of the South Island may have severe gales at times, while parts of Nelson, Wellington and the Marlborough Sounds, and the east coast of the North Island from the Wairarapa to Napier, are also at risk.
Huge waves pummelled the south coast last April damaging homes and leaving one person in hospital. In response to the extreme weather event MetService introduced a wave warning system for Wellington's south coast and harbour.
A wave crashing on to the the road at Island Bay, Wellington, in April 2020. Photo: Supplied / Katie Hecker Scheid
Snowfalls in lower South Island
Snow began falling this afternoon in parts of Dunedin and flights were disrupted in Queenstown, Invercargill and Dunedin. All Air New Zealand flights in and out of Invercargill Airport were cancelled.
South to southwest swells of 6 to 8 metres were expected today and Tuesday for nearly all of the South Island, and the huge waves will continue to spread up the coasts of the North Island.
Metservice also issued a road snowfall warning for the Dunedin to Waitati Highway, with up to 4cm of snowfall expected on the ground.
Waka Kotahi said a 15km stretch of State Highway 1 from north of Dunedin to Waitati is too treacherous to drive on.
The agency is advising people to delay their travel as there is no other option.
Waka Kotahi urged motorists to drive to the conditions and avoid unnecessary travel if possible.
State Highway 87 in Otago is closed due to snow and the Milford Road, State Highway 94, has been closed overnight.
Also closed are SH90, SH85, SH8 and SH7.
Businesses in the small Otago town of Lawrence, however, were not being deterred by snow storms.
Prospector Cafe & Accommodation owner Fiona Anderson said the snow this afternoon was not settling enough to start a snowball fight.
She said outside resembled more of a slushy mess than a winter wonderland.
The cafe's $3 hot chocolate special managed to lure in some locals and motorists, she said.
The wintry weather has already disrupted flights in lower South Island, with Air New Zealand services in and out of Invercargill cancelled as gale force winds and sleety showers hit the city.
Snow fell as low as 200m in parts of Southland and Otago and more was expected on Tuesday morning.
Meanwhile, water tankers have been deployed in three urban centres in Horowhenua after flooding at the weekend overwhelmed water treatment facilities.
Five water tankers have been sent to Levin, Shannon and Tokomaru to help people conserve water.
Food supply businesses, restaurants and industrial water users have been asked to reduce using water or shut as supplies of clean drinking water in the district reach critical levels.