The Karangahake Gorge on State Highway 2 has closed as heavy rain and gale-force winds continue to lash the North Island.
Overnight, the weather hit so strongly that homes lost power and many transport networks were hampered.
Waka Kotahi said the gorge is closed between Waihi and Paeroa due to a slip blocking both lanes near the Crown Hill Bridge intersection.
"Contractors are arriving to clear the slip and provide traffic control. Police are currently turning vehicles around," Waka Kotahi said.
"The gorge is likely to remain closed for most of the rest of the day to enable crews to clear the road."
Drivers travelling to locations along the eastern side of the Coromandel Peninsula need to use the Thames Coast Road, SH25. If drivers are heading to destinations within the Bay of Plenty, including Katikati or Tauranga, then they need to use SH29.
Despite the heavy rain and strong winds, Fire and Emergency said it has had no reports of major damage.
Some Kiwis woke up to no power on Monday morning, with Top Energy NZ reporting some unplanned outages.
About 159 households in the Far North woke to no power on Monday morning, according to Top Energy's website.
There are also around 700 households without power in the Coromandel, according to Powerco.
The bad weather has also affected three of One New Zealand's cellphone towers, according to chief executive Jason Paris.
"Three @onenzofficial sites down due to power cuts in Kawakawa, Newton (Hamilton) and Te Reinga (Hawkes Bay)," Paris said.
Paris said generators were immediately deployed and he estimated it will all be fixed by 8:30am.
"We will keep you updated through the weather event."
MetService said an "active front" with a subtropical low will move south over the upper North Island on Monday, then onto central New Zealand on Tuesday, bringing periods of heavy rain and easterly gales.
The forecaster said parts of the South Island are also in the firing line with a humid northwest flow with an embedded front expected to bring periods of heavy rain to Westland on Tuesday and Wednesday.
There are still 10 weather warnings and watches in place, with NIWA warning rivers will "respond rapidly" to this heavy rain.
An orange heavy rain warning is in place for the Coromandel Peninsula, Bay of Plenty west of Kawerau, including Rotorua, Gisborne north of Tokomaru Bay, Tasman northwest of Motueka and Westland south of Otira.
MetService warns heavy rain may cause streams and rivers to rise rapidly, surface flooding and slips are also possible and driving conditions could be hazardous.
A heavy rain watch is also in place for the Tongariro National Park, Buller south of Karamea, Fiordland north of Doubtful Sound and Bay of Plenty from Kawerau to Te Kaha.
The forecaster has also issued a strong wind watch for Westland south of Fox Glacier.
MetService has lifted an orange heavy rain warning for Northland on Monday morning while a heavy rain watch has also been lifted for Auckland including Great Barrier Island. MetService said the threat of rainfall amounts reaching warning criteria has passed.
A strong wind watch has also been lifted for Auckland about and north of Albany, including Great Barrier Island and also the Coromandel Peninsula and eastern Waikato near the Coromandel and Kaimai ranges with the threat of easterly and northeast winds reaching severe gale now passed.
New Zealand is going through a "wet period"
MetService Meteorologist John Law told AM on Monday New Zealand is currently going through a "wet period", but it isn't on the scale of Cyclone Gabrielle.
Law said active high pressure to the east of New Zealand is acting as a "block", keeping the bad weather over the country.
"As this rainfall moves in from the north and the west it doesn't have an awful lot of places to go, so it slides over us," Laws said.
"We are looking at this area of low pressure coming in from the north that brings with it warm, moist, wet air and we have more rainfall sliding down the country.
"With that high out towards the east, it sits there and it hasn't got anywhere to move. So we are looking at a prolonged period of wet weather as we go through today, but even through the rest of this week as well."
Laws said they're keeping a "very close eye on" the Coromandel and the Bay of Plenty as the bad weather moves south.
Transport chaos
Waka Kotahi NZ Transport Agency (NZTA) alerted motorists on Monday morning to delays on State Highway 1 Bombay to Ramarama.
Two crashes have been cleared from northbound lanes, but there are still delays in the area with emergency services still in attendance.
State Highway 1 between Warkworth and Wellsford has just reopened to traffic in both directions on Monday morning after being closed because of an underslip.
Waka Kotahi is also warning it is prepared to close the Auckland Harbour Bridge if necessary.
"At this stage, wind gusts have not exceeded threshold levels however we are constantly monitoring wind speeds, working closely with MetService," a spokesperson told Newshub.
"Maintenance crews are on the network ready to react and close lanes on the bridge if wind gusts do exceed these levels. The safety of road users is our top priority and we won't hesitate to reduce speeds, close lanes or close the bridge if necessary."
"Not what we need right now"
The Coromandel is bracing for a month's worth of rain in just two days, with Thames-Coromandel Civil Defence controller Garry Towler saying it's the "last thing we need right now".
"It's not pretty - this is the last thing we need right now," Towler said.
"It's the next five to seven days that really concern us. We are planning now for perhaps a metre of rain in the next seven days, certainly 700mm-plus."
With up to 220mm of rain expected for the Bay of Plenty by Tuesday and 180mm for Coromandel, residents in low-lying areas are warned to be on alert. And for those perched high on hillsides, Towler said they will be mobilising more building inspectors to come and assist.
A family in the Waikato town of Te Aroha had a rude surprise on Monday morning when they went to check on their backyard.
They found their trampoline had been uplifted and flipped over by high winds.
The wild weather has also caused parts of State Highway 25, just north of the Ruamahanga boat ramp, to close after a slip blocked the southbound lane, according to NZTA.
NZTA urges motorists to drive with caution and to expect delays.
Newshub reporter Karen Rutherford told AM from Whangamatā the weather overnight wasn't "too bad" compared to Cyclone Gabrielle.
"It was a walk in the park so far. We had 81mm of rain overnight up in the ranges, that will take around 4 to 5 hours to come down," Rutherford said.
"There's been a lot of work to clear culverts and drains in preparation for this event but we are expecting to get another 70mm of rain before tonight and that brings the total for this particular weather event to 300mm and of course there's up to a metre expected by the end of the week."
As the weather moves south, Rutherford said the Bay of Plenty is in the firing line with 190mm of rain expected.
"The Bay of Plenty should be on alert today west of Kawerau, including Rotorua. They're expecting up to 190mm as well as the Tasman District and Westland too," she said.
"Those two regions as well as the Bay of Plenty, will be feeling the effects of this atmospheric river that we keep hearing so much about."
Rutherford said the weather hasn't caused any disruptions to the roads in the Coromandel but added Waka Kotahi will be out making assessments on Monday.
