Salvage crews are still unable to get on board the "fragile" cargo ship Rena as rough seas and strong winds batter the stricken vessel.
Weatherwatch.co.nz said winds of 80 to 120km/hr were likely to hit exposed areas in the east and south of both the North and South islands.
Head forecaster Philip Duncan said that was likely to cause difficult conditions at the Rena, which is grounded on Astrolabe Reef off Tauranga, until Saturday.
Conditions were expected to worsen at the vessel tomorrow.
Maritime New Zealand Salvage Unit Manager Arthur Jobard said salvage teams could not safely board the Rena amid choppy seas and strong wind gusts.