Wild weather is expected to batter most of the country in the coming days, with thunderstorms predicted today ahead of gale-force winds and heavy rain.
It comes as a king tide is forecast to start from 10am in the Auckland area and would likely affect low-lying areas like Tamaki Drive.
Forecasters say it's still too early to confirm exactly where Cyclone Oma will hit, but either way New Zealand will be on the receiving end of some heavy rain and strong winds.
The cyclone was expected to move southwest away from New Caledonia in the next two days.
It was then expected to move southwest towards the southern Queensland coast.
"However, there is a chance that it could recurve towards southeast during Friday and possibly move back north again during the weekend."
Heavy rain, winds and storm surges from the cyclone uprooted trees, destroyed homes and food crops in Torba and Sanma provinces in Vanuatu.
The Vanuatu Daily Post reported the main damage on all islands was coastal destruction.
Widespread damage was also reported in New Caledonia after power was knocked out for thousands of homes as well as downing trees and flooding roads.
MetService said thunderstorms and bands of rain were expected to affect western parts of the New Zealand's South Island and the central North Island today.
A slow-moving front was forecast to lie over southern Westland or northern Fiordland this morning, bringing further rain with heavy falls.
A heavy rain watch was in place for Westland South of Otira and northern Fiordland from until 1am Friday.
There was also a moderate risk of thunderstorms over southern Westland and northern Fiordland in the morning.
Further north, a trough crossing the central North Island during Thursday morning brings a low risk of thunderstorms to Waitomo, Taumarunui and North Taranaki during the morning.
MetService predicted king tides may affect Tamaki Drive and SH1 at Esmonde Road as well as some low-lying parts of Auckland today and tomorrow from 10am.
Low-lying areas such as Maraetai and Beachlands would see elevated tides of up to 3.7m.
"In preparation, Healthy Waters today laid sandbags on Tamaki Drive, near the stairs and boat ramp at Kohimaramara, as a precautionary measure while the area is under further investigation for tidal flooding risk," Auckland Emergency Management acting director Sarah Sinclair said.
Looking ahead, a low was expected to approach the North Island from the Tasman Sea, bringing rain and showers across the island late on Friday and Saturday.
Weather could become more fierce on Sunday in central New Zealand as the low was expected to deepen, bringing rain and strong south to southwest winds.
"There is low confidence of warning amounts of rain in the east from North Otago to Hawke's Bay on Sunday."
There was low confidence of severe south to southwesterly gales in exposed parts of northern Canterbury, Marlborough and the lower North Island.
Marlborough, including the Sounds, Wellington and southern Wairarapa, are also expected to experience gale-force winds with moderate confidence.
Temperatures were expected to be much cooler and snow could affect alpine passes in the South Island.
"On Monday, the low should move away to the east allowing a ridge of high pressure to slowly spread across the country from the west, with the wind and rain easing."