Auckland braces for severe winds, thunderstorms; monster 10m swells cancel Cook Strait ferries

NZ Herald

30-04-2025

MetService said the storm 'could be a significant weather event, with large amounts of rainfall expected between today and Friday' for the east of the South Island in particular.
MetService meteorologist Kgolofelo Dube said the heavy rain could mean further localised flooding, slips and poor driving conditions.
Unsettled weather conditions are expected to continue throughout today and into tomorrow. The following are newly issued and updated weather alerts. For comprehensive information on each alert, please visit our website at https://t.co/qHyE5zzql5
Click here… pic.twitter.com/7KWsX2PAt8
— MetService (@MetService) April 29, 2025
There is a moderate chance of thunderstorms for the upper North Island this afternoon including Northland, Auckland, Waikato and the Coromandel.
Severe wind gusts are also tipped to strike Auckland at rush hour tomorrow morning, with a heavy wind watch coming into force at 7am.
'Damaging' 130km/h winds for Wellington, 10m swells cancel ferries
Cook Strait ferries have been cancelled until Saturday because of monster 10-metre swells caused by the severe winds.
A strong wind warning will begin for coastal areas of Wairarapa at 9am and last 15 hours. In Wellington, the watch will begin at 3am and last for 21 hours.
As a rule of thumb, big wind 🌬️ = big waves 🌊.
Significant wave heights are forecast to reach 7-10 meters offshore.
Combined with a King Tide, the risk for coastal erosion & possible flooding is elevated.
Stay up-to-date with marine forecasts & warnings from @MetService. pic.twitter.com/7UCAE28TIN
— NIWA Weather (@NiwaWeather) April 29, 2025
MetService said the wind, an unusually strong southerly, threatened trees which were typically only at risk from northerlies.
'This means that trees ... may be more vulnerable ... making them more prone to damage.'
MetService has also issued the watch for Marlborough Sounds, Horowhenua and Kāpiti Coast, inland areas of Wairarapa, the Tararua District, and Hawke's Bay south of Hastings tomorrow.
The National Institute of Water and Atmospheric Research reported gusts may reach 120km/h in some places. MetService said winds could hit 130km/h.
Across the Cook Strait, the same watch will begin for Coastal Marlborough south of Blenheim, including the Kaikōura Coast at 1am and last for 21 hours.
MetService is urging these communities to prepare for trees and powerlines to be damaged and to tie down any unsecured structures like trampolines.
Damaging wind is a real concern for parts of the lower North Island, including Wellington, later today & Thursday.
Gusts may reach 120+ km/h.
Likely impacts include:
🌬️ Damage to trees
🌬️ Risk of power cuts
🌬️ Difficult travel
Stay on top of weather warnings from @MetService. pic.twitter.com/E4OPApFHoQ
— NIWA Weather (@NiwaWeather) April 29, 2025
'I can imagine that as well there'll be some kind of transportation issues with those strong winds,' Dube said.
A strong wind watch will begin at 7am for Auckland, Great Barrier Island, Coromandel Peninsula, and Waikato north of Hamilton, with warnings the westerly winds may turn to severe gales in exposed areas.
Cantabrians told to brace for 40 hours of rain
Meanwhile, multiple regions in Canterbury were told to brace for close to 40 hours of rain, some even more.
State Highway 1 at Greta Valley in North Canterbury was blocked about 1.20pm today due to a slip near Stonyhurst Rd. The Christchurch City Council said roads were flooded in New Brighton and Wainoni.
A heavy rain warning was issued for the Kaikōura Coast and ranges, Canterbury about and north of Amberley, between Amberley and Timaru, including Christchurch and Banks Peninsula at 10am.
In Kaikōura, residents have been warned to expect between 180-230mm of rain over 44 hours, those north of Amberley should expect between 160-210mm over 35 hours and 120-160mm is forecast for Christchurch and Banks Peninsula over 32 hours.
Along with the heavy rain, snow is also expected to fall as the wintry blast sends temperatures plummeting.
Dube said cold fronts passing over the country from the south were the driving force behind the dropping temperatures.
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A heavy snow warning is in place for Canterbury high country south of the Rangitata River, with MetService telling residents to expect 12-20cm of snow to settle above 800m, with lesser amounts down to 700m.
A road snowfall warning will begin tonight for Arthur's Pass (SH73), Porters Pass (SH73) and Lindis Pass (SH8) and tomorrow morning for Lewis Pass (SH7).
Three to 5cm of snow is expected to settle on the roads near the summit, with lesser amounts lower than 700m.
A heavy rain watch is in place for Bay of Plenty about and west of Ōpōtiki and Wairarapa.
The same warning will apply for Wellington tonight at 6pm and last for 45 hours.