Cyclone Lusi will bring gale-force winds, lashings of rain and probably power cuts, MetService warns.
The storm has already caused devastation in the Pacific, with at least three dead in Vanuatu.
It is forecast to move out of the tropics today and track west of the North Island tomorrow, before crossing the South Island on Sunday, according to the latest MetService forecast.
Severe weather warnings have been issued for Northland, Auckland, Coromandel Peninsula, Bay of Plenty, Gisborne, Nelson and Marlborough.
Northland should expect 80mm-100mm of rain by tomorrow afternoon, MetService said.
Northland Civil Defence Emergency Management Group spokesman Graeme MacDonald said the combination of gales and heavy rain could cause erosion and flooding in low-lying coastal areas.
As a general rule Northlanders are familiar with the weather-related precautions they needed to take and typically coped with storms well, he said.
"Both locals and frequent visitors to our region are familiar with the spots that regularly flood and/or slip during heavy rain events and usually take such things in their stride."
With the strong winds and storm surges predicted, people were advised to secure any belongings they thought might be at risk and keep up to date with the latest weather forecasts, Mr MacDonald said.
Similarly, boaties - if they had not already done so - should make sure their vessels were secure, he said.
Spokesman Steve Macmillan said all Northpower electricity network maintenance in the Kaipara and Whangarei Districts had been stopped and hardened ready for Cyclone Lusi.
Also Northpower says:
* A full storm plan in place and have been preparing all week
* 12 Northpower crews and dozens of Line Mechanics are on stand-by now and will remain on call until Monday
* When outages occur we will have crews isolate and make save depending on the severity of the storm and access to outage areas
* Follow up crews will be dispatched in day-light to complete repairs
* Members of the public should stay clear of downed power lines, keep others clear and keep animals clear
* We also ask that they report any faults in Kaipara or Whangarei Districts to 0800 10 40 40 where we will also have regular updates on power outages
*It is also timely to remind people to keep an eye on their neighbours
Here is a link to a great weather map - http://earth.nullschool.net/#current/wind/surface/level/orthographic=-184.92,-34.12,640
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