The first drops of a wet weather front expected to drench much of the country over the next 24 hours are already falling on Northland.
Residents in Kaitaia got a sprinkling of 7.6mm within an hour early on Thursday morning before the front began it's rapid move toward Auckland.
By 10am Whangarei, Auckland and the Coromandel Peninsula had their first taste of what's expected to come.
Tamaki Drive, running along Auckland's waterfront from the city centre to its eastern suburbs, was temporarily closed on Thursday morning because of flooding concerns from big swells and an incoming king tide.
Elsewhere, some campgrounds and walking tracks are also being closed across the country's north with the manager of Piha Domain Camping Ground west of Auckland asking campers to evacuate.
Fiona Anderson posted a message to Facebook saying a king tide on Thursday combined with powerful waves, winds and torrential rains meant conditions at the Piha ground could become dangerous for human life.
Auckland can expect to receive falls up to 90mm and buffeted by wind gusts blowing up to 120 kilometres per hour in the coming hours, while Coromandel and Bay of Plenty will be among the worst hit regions with falls between 130mm and 150mm anticipated.
MetService is also warning coastal flooding is possible in parts of eastern Northland as the low pressure front brings in large swells coinciding with a king tide.
The wet weather will then move south to Taranaki and into Nelson and Marlborough in the South Island late on Thursday where continued heavy falls are expected into Friday.
The fast-moving front is expected to clear the country by Saturday.
WeatherWatch has warned the front is likely to bring flash flooding and big swells that pose a particular risk to trampers, swimmers, and boaters while driving could be hazardous for tall trucks and motorcyclists.
Humid conditions mean isolated heavy falls are also expected elsewhere in the South Island with the MetService putting in place a severe thunderstorm watch for Southland and Queenstown in Otago through to the Canterbury high country.
The Christchurch City Council has warned residents to brace for the possibility of flash flooding as up to 40mm is expected to hit on Friday.