The storm being tipped as one of the biggest to hit New Zealand in a decade has touched down with force.
In the Far North, winds are getting stronger and rain more intense, with metereologists warning that conditions can only worsen in what may be a record breaking tempest.
MetService says by the time it reaches northern parts of the country, the storm is likely to have significant destructive potential, with wind gusts of more than 110 kilometres an hour.
Auckland's Civil Defence headquarters is on alert.
Spokesman Harry O'Rorke says people need to act now by picking up rubbish, and checking drains and spouting before the storm hits.
Once it arrives, North Islanders will likely be advised to stay home and not travel unless it's necessary.
O'Rorke also says people should also close all curtains and windows to slow down any flying glass or other airborne objects.
He also says animals should be brought inside so they are protected.
Civil Defence warns that heavy rain and strong winds may cause flooding and power outages in some areas.
Radio Network Head Weather Analyst Philip Duncan says the storm has now developed an eye, on track to pass over central Auckland around midnight Sunday morning.
Far North feels it first
Winds are already gusting at 130 kilometres an hour at the top of the North Island.
Sensors in the Far North show the pressure is dropping very rapidly, and the storm remains on track to unleash its full force on the eastern side of the island tonight.
It has also trapped cold air over the central plateau, which means there is likely to be snow on the Desert Road overnight.
Whangarei and Kerikeri are the worst hit so far.
The Fire Service is dealing with several downed trees, one of which has gone through a house.
Several properties have also lost their rooves, but there is minimal flood damage so far.
As many as 1,000 Northland households are without power after lines were ripped out by gales.
A couple of houses in the in St Heliers and Devonport areas of Auckland are already having flood problems.
