Despite almost 50mm falling on Kerikeri, MetService is now forecasting Northland - which had earlier been tipped to suffer the brunt of the gales and rains - to have escaped the storm's worst.
Piha campground manager Fiona Anderson evacuated campers today due to the weather being "dangerous for human life".
"There's some big weather systems coming in, 6m swells coming from two different directions, torrential rain forecast between 10pm and 12am tonight which is when our high tide will be... and 130km/h winds predicted," Anderson said.
"This is not something I can afford to be flippant about. If this all comes together over Piha tonight I'd be putting people's lives at risk if they were still here."
The forecaster said the heaviest falls were now moving southeast across the country through the Coromandel Peninsula towards the Bay of Plenty and Taranaki.
In the Coromandel, which was forecast to receive up to 150mm of rain, civil defence controller Garry Tower said fire crews had been visiting low-lying coastal areas urging freedom campers to move to higher ground.
He said the Thames-Coromandel District Council had also activated its emergency centre to monitor the storm overnight as it feared possible flooding, landslips and damage to power networks.
Many walking tracks in the area had also been closed by the Department of Conservation. Taranaki, and Nelson and Marlborough in the South Island, are expected to receive heavy falls from the front late on Thursday and into Friday.
The fast-moving front is expected to clear the country by Saturday.
Humid conditions elsewhere in the South Island, meanwhile, mean isolated heavy falls are also expected in Southland and Queenstown in Otago through to the Canterbury high country, which are all subject to a MetService thunderstorm watch.
The Christchurch City Council has also warned residents to brace for the possibility of flash flooding as up to 40mm is expected to hit on Friday.
