The wild weather that has battered the South Island's West Coast is tracking north - bringing rain and possible thunderstorms to the North Island.
A "red warning" has been issued for Buller and Westland - as heavy rain caused flooding, slips, major road closures, evacuations and left people trapped on the roofs of their cars needing to be rescued by helicopter and front-loader truck.
A state of emergency has been declared in Marlborough by the region's deputy mayor Nadine Taylor, while hundreds of properties have been evacuated. A state of emergency has also been declared in Buller - where last night more then 820 people were forced from their homes.
MetService said the bad weather would move swiftly up the country today - bringing with it periods of heavy rain to much of the North Island.
"Bang, it's going to accelerate right across [the North Island]. It will be quite brief moving through," he said.
The weather authority has issued a spate of warnings covering the North Island - including an island-wide strong wind watch, heavy rain warnings for Taranaki, parts of Bay of Plenty, the Tararua Range and Wellington.
The weather has disrupted travel in both Auckland and the capital.
At least 28 domestic flights have been cancelled at Wellington Airport, while four Fullers Waiheke Island ferry services were canned today.
Wellington City Council received more than 20 reports of flooding on roads and private properties since 8am this morning as the rain continued to bear down on the capital city.
Along with pelting rain, Wellingtonians have also been enduring strong winds, with gusts reaching up 130km/h in exposed places.
The strong gusts have also blown roofs off homes in the capital as flooding and debris is reported across the region.
A burst wastewater main has spilt sewage on to SH1 northern of the capital as well, with Wellington Water advising motorists to expect delays at Paremata, between the Aotea turnoff and Plimmerton, 200 metres north of Aotea lagoon.
The public were also asked to minimise water use and avoid swimming in Porirua harbour for the next 48 hours.