Heavy rain, gales to pelt upper North Island
Batten down the hatches - a violent subtropical low bearing down on the country is bringing severe gales, heavy rain and big seas.
The harsh conditions are forecast to slam into the upper North Island tomorrow, with the rest of the North Island and northeast corner of the South Island also likely to be in the firing line as the low moves south.
"After the heavy thundery downpours that moved across many parts of New Zealand during the weekend, Monday provides a brief respite from the weather. However, the outlook for the rest of the week is bleak," MetService said.
The low was heading for northern and eastern parts of New Zealand and was set to bring heavy rain, strong to severe easterly gales and large waves.
Intense rain and severe easterly gales would spread down across the North Island, reaching the top of the South Island from late tomorrow.
MetService meteorologist Daniel Corbett said the position of the subtropical low in relation to the northeast coast of the North Island could result in beach erosion and the risk of flooding from the sea.
The heaviest falls of rain were likely in eastern Northland, Coromandel Peninsula and Gisborne tomorrow afternoon and evening. Around 100mm of rain was expected in those areas, with 150mm in the ranges of Gisborne through to early Wednesday, MetService said.
"People are advised that rivers and streams will rise rapidly, and slips and localised surface flooding are likely."
Southeasterlies were expected to rise to severe gale in Northland, Auckland and Coromandel Peninsula from tomorrow afternoon through to midnight, with damaging gusts up to 130kmh in Auckland and Coromandel Peninsula.
"Winds of this strength are likely to bring down trees and powerlines, may cause damage to insecure structures, and make driving hazardous, especially for motorcycles and high-sided vehicles."
Rainfall could also be heavy in northern Auckland, western Bay of Plenty and Hawke's Bay, Wairarapa and eastern Marlborough. Southeasterlies could also reach severe gale strength for a time on Wednesday in Gisborne, North Island areas west of the main ranges, and about the Marlborough Sounds.
Corbett said the intense low would gradually weaken on Thursday. It would have left by the end of the week, but disturbed westerlies were likely to take its place.