A wind warning is in place for the Auckland Harbour Bridge overnight with forecast gusts of up to 80km/h.
Speed limit reductions and lane closures are possible on the bridge between midnight and 4am, the New Zealand Transport Agency said.
The lane configuration would remain as four lanes in each direction while the wind was expected to rise.
“If the alert period is extended, this configuration may remain in place during the Wednesday morning peak traffic period,” a spokesperson said.
“Drivers of high sided vehicles and motorcyclists are advised to avoid the Auckland Harbour Bridge and use the western ring route on State Highways 16 and 18.”
The Far North was placed under a red severe thunderstorm warning on Tuesday afternoon as a “significant low” began moving south across New Zealand.
The warning was issued when a line of “severe thunderstorms” was detected near Cape Brett moving in a southwesterly direction at 4.30pm, Metservice said.
The warning was lifted at 5.20pm.
A section of State Highway 1 was closed due to flooding at Te Paki near Cape Rēinga at around 1.45pm, NZTA said.
“There is no detour available.”
Cook Strait ferries cancelled
Interislander ferry sailings through the Cook Strait would be cancelled from 8.30pm on Wednesday through to 2.30am on Friday.
MetService was forecasting large swells of up to 7 metres in the strait.
“We are putting on additional return sailings on Saturday evening and Sunday morning to accommodate impacted customers,” Interislander service operations manager Tungane Rosson told 1News in a statement.
“We are monitoring the forecast for Friday, and if conditions don’t improve, there are also likely to be further cancellations.”
‘Significant low’ expected to deepen
The poor weather was the result of a “significant low” approaching the country from the north which was expected to deepen across New Zealand on Wednesday and Thursday.
The system has prompted numerous weather warnings and watches around the country.
“It is expected to bring significant rain and severe southerly gales to parts of the country as well as heavy snow to higher parts of Canterbury,” the national forecaster said.
Orange heavy rain warnings were issued for Gisborne/Tairawhiti north of Tolaga Bay, Kaikōura coast and ranges, Banks Peninsula, and Canterbury, about and north of Amberley.
Gisborne/Tairawhiti north of Tolaga Bay’s warning would be in place 12 hours from midnight Tuesday until noon Wednesday. Locals could expect 70-100mm of rain, with peak rates of 15 to 25 mm/h expected on Wednesday morning.
The Kaikōura coast and ranges warning would cover a 42 hour period from noon tomorrow until 6am on Friday. Locals can expect 150 to 200mm of rain, with peak rates of 15 to 25 mm/h expected on Wednesday night and Thursday morning in the ranges. Snow lowering to about 1000m is expected on Thursday.
Banks Peninsula and Canterbury, about and north of Amberley, are under a warning that lasts for 38 hours from 4am tomorrow until 6pm on Thursday. Locals can expect 140 to 180mm of rain, with peak rates of 10 to 20 mm/h expected on Wednesday evening and Thursday morning. Snow gradually lowering to 700 metres was expected by Wednesday night.
Heavy rain watches have been issued for Northland, Wellington, Canterbury south of Amberley, and Christchurch (not including Banks Peninsula).
MetService warned locals that streams and rivers may rise rapidly, making driving conditions difficult.
“Clear your drains and gutters to prepare for heavy rain. Avoid low-lying areas and drive cautiously.”
A severe thunderstorm watch was also issued for Northland. A “band of rain with embedded thunderstorms” is expected to affect the region today.
MetService said for Northland, especially north of Whangārei, there was a moderate risk that thunderstorms embedded with areas of rain could be “severe”, with localised rainfall rates of 25-40mm/h (or possibly more) between 10am and midnight today.
“The risk of downpours decreases in the far north this evening. Downpours are possible in localised places and may occur regardless of whether there is thunderstorm activity or not,” MetService said.
“Rainfall of this intensity can cause surface and/or flash flooding, especially about low-lying areas such as streams, rivers or narrow valleys, and may also lead to slips.
“Driving conditions will also be hazardous with surface flooding and poor visibility in heavy rain.”
Meanwhile, a heavy snow watch was issued for the Canterbury High Country south of the Rangitata River. Road snowfall warnings were issued for Arthur’s Pass (SH73) and Porters Pass (SH73).
Strong wind watches were issued for Marlborough Sounds, Buller, Grey and Westland Districts, Nelson Lakes District, and Wellington.
Full list of watches and warnings
Heavy rain warnings – Orange
Gisborne/Tairawhiti north of Tolaga Bay – 12 hours from midnight Tuesday to noon Wednesday.
Kaikōura coast and ranges – 42 hours from noon Wednesday to 6am Friday.
Banks Peninsula, and Canterbury about and north of Amberley – 38 hours from 4am Wednesday to 6pm Thursday.
Heavy rain watches
Northland – 14 hours from 10am to midnight, Tuesday.
Wellington – 18hrs from 6pm Wednesday to noon Thursday.
Canterbury south of Amberley, and Christchurch not including Banks Peninsula – 39 hours from 3am Wednesday to 6pm Thursday.
Heavy snow watches
Canterbury High Country south of the Rangitata River – 16 hours from 6pm Wednesday, 30 April to 10am Thursday, 1 May.
Strong wind watches
Marlborough Sounds – 18 hours from 6pm Wednesday to noon Thursday.
Buller, Grey and Westland Districts, and Nelson Lakes District – 27 hours from noon Wednesday to 3pm Thursday.
Wellington – 30 hours from midnight Wednesday to 6am Friday.
Road snowfall warnings
Arthur’s Pass (SH73) – 10 hours from 9pm Wednesday to 7am Thursday.
Porters Pass (SH73) – 14 hours from 9pm Wed to 11am Thursday.