MetService has issued strong wind and heavy rain watches and a warning, as a low-pressure system sweeps over the country from Thursday evening, delivering a burst of severe wind and rain for some this weekend.
A heavy rain warning has been issued for the Coromandel Peninsula with rain expected from the early hours of Friday morning.
MetService warns rain of 100 to 140mm, which may cause streams and rivers to rise rapidly as well as surface flooding and slips.
A heavy rain watch has been issued for Northland, Auckland north of Takapuna, including Great Barrier Island and Hawke's Bay north of Hastings from Thursday evening continuing into Friday.
Heavy rain is expected to hit Bay of Plenty including Rotorua and Gisborne on Friday.
Niwa said over the next 48 hours moisture from the tropics would make its way to the upper half of the North Island.
"Wind gusts of 70-100 km/h coming from an unusual direction, increasing risk for tree damage & power cuts."
It said Friday would likely have the worst weather.
Strong easterly wind watches are in places for Northland from Bay of Islands southwards, Auckland north of Harbour Bridge including Great Barrier Island, and the Coromandel Peninsula.
MetService said conditions were expected to be particularly stormy over eastern coasts with a forecast for waves of 3-5m.
It said this, in addition to the heavy rain forecast, would make coasts vulnerable to damage.