The Coromandel Peninsula is bracing for Cyclone Hale, with officials warning that road slips, fallen trees and power cuts are possible as the storm barrels towards the North Island.
Waka Kotahi NZTA said New Zealanders in parts of the country forecast to feel the brunt of the weather should "avoid unnecessary travel", while one council said people should move to somewhere safe by Monday night.
"Cyclone Hale is expected to impact on the Coromandel late this afternoon and early evening bringing heavy levels of rain and high winds," the Thames-Coromandel District Council said on Monday afternoon.
"It is anticipated that there will be further road slips and fallen trees over the next two days until the cyclone passes on Wednesday afternoon. Some roads may become impassable.
The centre of the storm, which has formed over the Coral Sea but won't be a tropical cyclone by the time it hits New Zealand, is projected to be near the Coromandel Peninsula on Tuesday evening, the latest Metservice forecast track map released on Monday morning shows. However, the effects of the low may be felt much earlier.
Over the course of Tuesday night and Wednesday, it will move southwest across Waikato before swinging over Taupo and southeast towards Hawke's Bay, where it will depart New Zealand.
"Cyclone Hale is approaching the North Island today, bringing rain and strong east to southeast winds to many areas," Metservice said on Monday morning.
"Watches and Warnings for heavy rain and severe gales are now in force. This is likely to be a significant adverse weather [event] with widespread effects, and more areas are likely to be added as the system moves closer and its exact track and intensity becomes more certain.
"People are urged to keep up to date with the latest forecasts and warnings, and to stay alert to bulletins from local authorities."
Currently, there are three heavy rain warnings in place for Coromandel Peninsula (8pm Monday to 9pm Tuesday), Gisborne (8pm Monday to 11pm Tuesday) and Hawke's Bay (3am Tuesday to 8am Wednesday).
"Heavy rain may cause streams and rivers to rise rapidly. Surface flooding and slips are also possible and driving conditions may be hazardous."
There is also a heavy rain watch in place for southern and eastern Northland, as well as Auckland and Great Barrier Island for between 9pm on Monday and 6pm on Tuesday.
Three strong wind watches are in force for Coromandel and Great Barrier Island (9am to 10pm on Tuesday), Auckland and some of Waikato (3am Tuesday to 1am Wednesday) and Bay of Plenty and Taupo, mostly near the eastern ranges (10am Tuesday to 1am Wednesday).
A forecast from NIWA Weather also shows the weather system hurtling towards New Zealand, approaching from Monday night. By Tuesday night, most of the storm is over the Coromandel Peninsula and surrounding areas.
Waka Kotahi NZTA is asking New Zealanders in impacted regions to "avoid unnecessary travel" from Monday night until Wednesday morning.
Acting National Manager Maintenance and Operations Jaclyn Hankin said on Monday that heavy rain could cause surface flooding, trigger slips and cause streams and rivers to rise rapidly. That may require Waka Kotahi to close some state highways.
"Our contractors will be working hard, doing what they can to keep the state highway network safe and open," said Hankin.
Strong wind could lead to speed reductions or lane closures on the Auckland Harbour Bridge on Tuesday and Wednesday, just as people head back to work after the Christmas and New Year holidays. Gusts of between 75 and 85km/h are currently forecast for Auckland and eastern Northland.
If people have to travel, Hankin said they should "expect the unexpected and remain alert".
"Drive to the conditions, view the latest weather forecast on the MetService website (metservice.com) and check your intended route for hazards or disruptions before setting out using the Waka Kotahi interactive Journey Planner website (journeys.nzta.govt.nz).
"Stay alert for unreported hazards, such as surface flooding, slips, fallen trees and branches, and downed powerlines.
"If you must travel, slow down and maintain a greater following distance between your vehicle and the one in front."
People should also watch for contractors working on the road.
Meanwhile, the Thames-Coromandel District Council is urging those at the holiday hotspot to brace for a wet start to the week, saying its eastern seaboard is in for a "hammering".
"We are not sugar coating this one, it will hit hard and likely cause coastal damage as well as the usual slips, surface flooding and power outages," said Civil Defence controller Garry Towler.
"The main areas of concern are erosion and inundation at Brophy’s and Buffalo beaches in Whitianga, erosion and structure damage across beaches all the way down to Whangamatā.
"Everyone on the Coromandel, especially on the eastern side needs to stay up to date and be somewhere safe by Monday night, ready to ride this out for at least 24hrs."
The council said the weather system will dump more than 230mm of rain in 24 hours with easterly gales and gusts exceeding 110km/h. This will begin on Monday night and then peak Tuesday before passing on Wednesday afternoon.
Storm surges of about 30cm above the three high tides over this time are likely.
It's the latest blow to holiday goers on the Coromandel Peninsula who were impacted by wet weather for much of last week. Heavy rain caused chaos on the roads there, with some blocked by slips.
The Thames-Coromandel District Council has shared a drone picture of a slip under The 309 Road between eastern and western Coromandel.
"Council roading teams are working on assessing the damage from last week’s storm event and undertaking repairs where possible. Both the Tapu-Coroglen Road and The 309 Road have suffered damage with two slips under The 309 Road reducing the roads to one lane.
"While both roads are suitable for light vehicle usage, Council advises that heavy vehicles should avoid both routes until the full extent of the damage can be assessed."
