The system will hover there for a couple of days before being forced away by a high pressure system on Friday.
MetService meteorologist Marylin Avery said the weather system was moving very slowly as it passed through the Waikato today.
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"Strong winds are still expected south of there, but the winds are lighter, and it's showery further north.
"There will be heavy falls for the Bay of Plenty, Gisborne and the Hawkes Bay."
More than 300mm of rain is possible in the ranges around Gisborne and Hawkes Bay through to Friday morning, with 100mm to 150mm in lower areas.
Photo / Fiona McDonald
Further significant rain is also likely in parts of Bay of Plenty, with 100mm to 200mm of rainfall.
Lesser amounts of rain are likely in eastern Taihape, the ranges of Wairarapa, eastern Marlborough and northwest Nelson.
In the Tararua Range, 70mm to 100mm of rain is expected to fall in the 18 hours until 3am tomorrow.
The rain should ease in Canterbury and Marlborough tomorrow morning.
"Strong east to southeast gales could be severe for a time today in western areas from the central North Island high country down to the Kapiti Coast, and also in the Marlborough Sounds, western parts of Nelson, Buller and Westland," Ms Avery said.
She said the system was still potent.
"It's moved a bit south, and there's onshore winds and very moist air. It's still the same weather system, still quite strong."
A high pressure system just south of the country will start pushing north tomorrow, and spread further north on Friday and Saturday as the low pressure system moves away to the east.
"In the eastern North Island, the wind will abate and the rain will ease by Friday."
All road closures from flooding and fallen trees have now been reopened, although there is still caution for SH25 at Hikuai for slight surface flooding.
Browns Bay, Auckland. Photo / Karl McIntyre
Damage and destruction
Forty thousand people are still without power in the Auckland region after the powerful storm left a trail of destruction across the upper North Island.
One child was taken to hospital with minor injuries after a tree smashed through a roof in Manly, Whangaparaoa, about 1.10am.
In Blenheim a 12-year-old girl was swept away by floodwaters on her way to school, saved only by the quick thinking of two passers-by.
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Emergency services in Auckland city attended more than 600 calls after midnight, as the city's streets were littered with debris.
Photo / NZ Herald reader
The Coastguard has issued warnings to the public to be wary of debris floating in the water after last night's storm.
Coastguard spokesperson Georgie Smith said over a dozen calls had been made overnight regarding boats adrift, which have been referred to the Harbourmaster.
A 52-foot fishing vessel in distress off the Coromandel coast has now been blown in to safety.
A distress call was sent from the vessel carrying three people at 3.30am after an anchor rope had been caught around its propeller.
"The winds were very strong and was pushing them to the rocks so they made a mayday call to Maritime radio," said Maritime NZ spokesperson Michael Flyger.
The call was coordinated with the Police Maritime Unit, and was downgraded when the wind changed and pushed the vessel to safety.
Fullers Auckland has been forced to close down their Bayswater ferry services after the marina received extensive damages overnight.
Fullers operations manager Tim Palmer said efforts were underway to restore services, but it is likely the terminal will remain shut until the weekend.
He said power outages across the North Shore also meant that services were disrupted at Devonport and Northcote Point, and passengers were unable to use HOP scanners on ferries.
Damage on Shortland Street, Auckland. Photo / Jun Dolon
Girl swept away in Blenheim
A 12-year-old girl swept away by a flooded Blenheim river while walking to school this morning was saved by two quick-thinking passers-by.
Police say a tragedy was averted when a 17-year-old man and another man leapt to the girl's aid.
The girl was swept away by a raging Taylor River, near High St, at about 8.45am.
The two men chased her along the river bank and eventually recovered her from the water near Beaver Rd, police said.
The 12-year-old girl has been taken to hospital in a serious condition.
The teenage rescuer has also been taken to hospital suffering mild hypothermia. The other man did not require medical attention.
Senior Sergeant Dan Mattison said the quick actions of the teenage boy and the other man involved in the rescue had saved the girl's life.
Power still out to tens of thousands
Scenic Drive, Titirangi. Photo / Meagan Ramages
Vector crews have worked throughout the night to attend to numerous faults after two huge wind blasts up to 145km/h swept through the city, one at 11pm last night and another at 1am.
Forty thousand customers are still without power in the Auckland region, Vector says.
Most power has now been restored to the 6000 outages in Auckland south of the Harbour Bridge.
In the northern region up to Warkworth, a further 15,000 have been restored, with 40,000 still without power.
Vector spokeswoman Sandy Hodge said 30 crews were working on the northern network, along with seven Treescape crews.
"If you are medically dependent and are without power, then please contact a family member or friend who has power, or if none of these options are available please go to your nearest hospital."
One of the Vector crews had a lucky escape when a large tree came down next to their truck, trapping the vehicle.
Photo / Helen Webber
About half of the customers who lost power across Tauranga and South Waikato have had their power restored.
High winds brought trees down across overhead lines on Powerco's electricity network, causing wide-spread power cuts starting from midnight.
Powerco Acting Electricity Operations Manager Phil Marsh said a total of 30,000 customers had lost power overnight and today.Supply had been restored to about 15,000 of these properties.The hardest hit areas were in Coromandel and Thames.
"Most of the damage has been caused by trees falling across lines," Mr Marsh said.
Extra resources were brought in the help restore the power quickly and safely, he said.
Photos: Auckland storm