Wild weather expected across the country from today will be one of the "bigger weather events" for some time, the MetService says.
Severe weather warnings were in place for both the North and South Islands with heavy rain and gales expected to hit on Sunday night.
The MetService was forecasting rain and gales for Northland, north Auckland, and Great Barrier Island on Sunday evening.
Between 60mm and 90mm was expected in some hill areas.
In the Coromandel Peninsula, Bay of Plenty and Gisborne north of Tolaga Bay, severe weather would hit Sunday night and Monday morning, easing in the afternoon or evening.
About 100mm to 150mm of rain was expected near the ranges, with the heaviest falls north of Gisborne.
The biggest rainfalls would be in Nelson, Marlborough, Canterbury and Otago on Monday and Tuesday, with up to 200mm expected.
Gales would hit across the North Island from Auckland to Kapiti, and parts of the South Island, including Nelson, Buller, Westland, Marlborough and Canterbury, on Monday.
The gales could be severe in Taranaki, Manawatu, the Kapiti Coast, valleys of Buller and Westland and around Banks Peninsula, the MetService said.
The severe weather was "one of the bigger weather events we are likely to see for a while", MetService forecaster Bob McDavitt said.
Streams and rivers would quickly rise, and there could be surface flooding in low lying areas. The weather was likely to make driving dangerous, causing slips in hilly areas, and damage trees and powerlines.
Forecasters expect the bad weather to spread further south by Monday night and Tuesday, and they urged people to stay up to date with the latest forecasts and warnings.
