MetService says an accurate path for Cyclone Hola will not really be able to be predicted until about Saturday night.
Meteorologist Georgina Griffiths said Hola is "really intense now" and is just beginning its recurve to the southeast from its current position between Vanuatu and New Caledonia.
She said an accurate forecast of Hola's path near New Zealand will not be known until Saturday evening, and urged people to keep up to date.
"That track is going to become very important," Ms Griffiths said.
"If I were living in Northland Coromandel or Gisborne I'd really be keeping up with that forecast for Monday, which is D Day."
With Hola following just weeks after Cyclone Gita ravaged parts of Nelson Tasman and the West Coast, Ms Griffiths said the number of cyclones this year hitting New Zealand was "not exceptional".
"We've only had three this year," she said, "but they are targeting New Zealand right now".
Ms Griffiths urged people to get their official forecast from MetService, as she said they are the only agency with the relevant tropical cyclone expertise.