Weather forecast: Rain, wind and waves yet to come

Don't relax just yet, forecasters are saying the worst of the weather is yet to come.

Rain from a severe front is now setting in across the north of the country, as authorities cancel ferry services in Auckland, close walking tracks and urge campers to move on from low-lying areas.

Auckland had been forecast to receive up to 90mm of rain and wind gusts blowing up to 120km/h as the front hit in the 12 hours after midday on Thursday.

This led Auckland Transport to replace some ferry services with buses, forced play to be halted at the ASB Classic international tennis tournament and saw waterfront road Tamaki Drive temporarily flooded at high tide.

Only 0.8mm of rain had fallen by 3pm as the severe front was yet to deliver all of its promised ferocity.

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.

The Strong Wind Warning remains unchanged for today, however, as winds turn strong northwesterly north of Manawatu as the low moves over central NZ on Friday, gusts of 120km/h may return for a time. ^AC pic.twitter.com/rjTHobpTgs

— MetService (@MetService) January 3, 2018

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.