The forecast offers little respite to residents still recovering from record rainfall and heavy flooding that left four people dead.
Auckland is on a heavy rain warning until 6pm Tuesday until 6am Wednesday and Northland from 4am Tuesday until 4am Wednesday.
The latest bleak forecast comes as one of Auckland Mayor Wayne Brown’s own staff has conceded “we’re doing a terrible job” in the emergency response.
The comment to a Stuff reporter before a mayoral press conference yesterday follows widespread scrutiny of Brown’s performance.
Asked about Auckland Council's response and the delay to declare a state of emergency in the city by Brown, new Prime Minister Chris Hipkins told TVNZ those were issues they would be looking at.
But the main focus at the moment is supporting Aucklanders over the next couple of days and dealing with the situation immediately in front of them."This is a locally-led response," Hipkins said.
Anything that Auckland has asked for, the central government has done its best to provide, he said.
"One of the things that we have absolutely heard from Aucklanders is that the communications have been too far and far between."
As a government, they would be supporting Auckland through this emergency.
"Cabinet will meet tomorrow and will consider a further response package and a further support package for Auckland."
Asked if he thought this was climate change, he said: "Yes."
"Climate change is real, it's with us. It's having an impact on our weather - we are seeing more of these extreme weather events.
"We're going to have to deal with more of these extreme weather events in the future. We need to be prepared for that."
Hipkins said he had been in regular contact with Auckland mayor Wayne Brown.In a conversation yesterday, Hipkins said Brown had indicated that more experienced management leadership needed to be provided - which has been.
"He also asked for some additional support with communications and we've supplied that."
Forty homes have been now red-stickered, meaning they are not safe to be inhabited, said Auckland Emergency Management deputy controller Rachel Kelleher. Another 151 homes have been yellow-stickered.
Red stickers mean an inspector has assessed a property as unsafe to enter. Yellow stickers can restrict access to certain parts of a building, or only to enter for a short time to remove valuables.
These homes are spread across the city and are affected by either or both flooding and slip damage.
In the Coromandel, authorities said the peninsula had been completely cut off yesterday after heavy rain pummelled the region, causing flooding and slips.
State Highway 25A, between Kopu and Hikuai, was closed due to a significant slip. Meanwhile, State Highway 25, between Whangamata and Waihi, and at Manaia, was closed due to flooding.
There was heavy rain on Saturday night in the Bay of Plenty, which led to at least one Tauranga home being destroyed by a landslip, residents being evacuated and more road closures.
The Waitomo district has joined Auckland in announcing a state of emergency. It took effect at 7.05pm on Saturday and expires in seven days.
Meanwhile, a freight train derailed near Te Puke due to rain on the tracks yesterday. KiwiRail said the train was travelling on the East Coast Main Trunk Line (ECMT) from Kawerau to Mount Maunganui when it went over a flooded section of track, east of Te Puke, about 5.30am.
The locomotive remained on the tracks but up to 10 wagons, carrying logs and pulp, derailed. The two-person train crew were not hurt. KiwiRail teams are inspecting the site, and regulators, including the Transport Accident Investigation Commission, have been notified. The section of the ECMT is closed at present.
Residents in already hard-hit areas like Auckland, Coromandel and Bay of Plenty were on watch yesterday for thunderstorms and more heavy rain.
MetService now says there could be heavy rain and thunderstorms as far south as the Marlborough Sounds and the Rai Valley, as well as Tasman. It has put in place heavy rain warnings for Auckland, Waikato, Waitomo, Mt Taranaki, Marlborough Sounds and Tasman northwest of Motueka.
Thunderstorm watches were also in place yesterday for Manawatu, Tararua and Kapiti-Horowhenua.
Auckland may be getting a month’s worth of rain or more in the coming days. MetService meteorologist Luis Fernandes said yesterday more wet weather could be expected for much of the North Island, with the northern parts again seeing the most rain.
Niwa said another "atmospheric river" was poised to bring more widespread rain, likely heavy, along with strong winds to the upper North Island.
"Current timing suggests late Monday into early Wednesday. Details likely to evolve between now and then," it tweeted.
WeatherWatch predicted isolated thunderstorms and wet weather yesterday and said the wet weather system was sliding back and forth.
"This means Auckland and other northern areas have more heavy rain — and more gales — mainly this Tuesday, with long dry spells today before the heavier showers are possible again. Over Sunday and Monday wet weather will spread back to a number of places, with isolated thunderstorms.
"Between slow-moving thunderstorms and the general rain forecast, Auckland City may still receive a further 80 to 120mm in the coming days. This is a month’s worth of rain, or more, still to move in this week," head forecaster Philip Duncan said.
"The wettest and windiest day looks to be later on Tuesday which may be stormy for some in Auckland and Northland."
Four people have died and one is missing after raging floodwaters and slips were caused by the unprecedented deluge of rain across Auckland on Friday — easily the city’s wettest day on record. A state of emergency remains in place across the region.
In a statement yesterday, police said search and rescue, who had been looking for a person swept away by floodwaters in Waikato’s Onewhero, had found a man’s body.
Formal identification is yet to take place, but police believe it is the missing man.
The body was found by a drone operator, about 1km from where he went missing.
Yesterday, police named 34-year-old Daniel Mark Miller as another victim of the floods.
Mr Miller was found dead in a culvert in Target Rd in Wairau Valley on Friday.
Another person was found dead after a landslip brought down a house in Remuera’s Shore Rd.
RNZ understands that the man was in his 80s and was a volunteer at the Museum of Transport and Technology, Dave Lennard.
A fourth person was also found dead in a flooded car park in Link Dr, Wairau Valley at 12.30am on Saturday.
Emergency officials announced yesterday morning that nine Auckland properties have been red-stickered, including several in Remuera. This number is only the tip of the iceberg, with more than 5000 properties across 25 suburbs needing some level of assessment.
Thousands of insurance claims have already been lodged amid widespread damage across the supercity.
The floods also conspired to ruin the Auckland Anniversary weekend plans for many, closing the airport and cancelling events including two Sir Elton John concerts on Friday and Saturday, and the Laneway Festival at Western Springs today.
Twenty-four homes have been evacuated due to a large slip in Maungatapu which crashed into homes in Egret Ave about midnight on Saturday.
Police confirmed no-one was seriously injured.
On Saturday, Prime Minister Chris Hipkins flew to Auckland’s Whenuapai air base aboard an Air Force Hercules. He met affected families and emergency services in West Auckland together with Emergency Management Minister Kieran McAnulty and Mayor Wayne Brown.
About 70 displaced people had visited Civil Defence Centres since they opened on Friday.
Mr Hipkins said Civil Defence payments had been activated and accommodation was available for displaced people.
"The levels of devastation in some areas is considerable."
He assured Aucklanders central government would be providing more support in the coming days and told residents to expect more bad weather.
The Transport Accident Investigation Commission has opened an inquiry into an incident on Friday in which an Air New Zealand Boeing 777 "lost control on the ground" during Auckland’s wild weather.
The commission said Flight NZ 124 from Melbourne landed at Auckland International Airport during wind gusts and very heavy rain.
Chief investigator of accidents Naveen Kozhuppakalam said shortly after touchdown, the pilot briefly lost directional control and the aircraft veered from the runway centreline.
While the pilot regained control, "there was damage reported to six runway edge lights and to the aircraft’s undercarriage assembly, including deflation of one tyre. We’ve received no reports of injuries to passengers or crew."
Kozhuppakalam has appointed two investigators.
Meanwhile, international flights at Auckland Airport resumed yesterday, following two days of disruption caused by the weather.
To help customers, Air New Zealand has added further capability to the manage booking function allowing customers booked on an Air New Zealand service the ability to rebook their cancelled international flight over the next 20 days. This has been extended from 10 days due to the limited capacity available.
Key points
— Auckland and Waitomo under a state of emergency.
— Death toll has risen to four.
— Heavy rain hit Coromandel and Bay of Plenty on Saturday night; Coromandel was cut off yesterday.
— More heavy rain forecast for North Island and the upper part of the South Island.
— Train derailed in Te Puke.
— The New Zealand Herald, RNZ and ODT Online