The moist northeasterly flow will continue to affect the North Island on Tuesday, with bands of rain affecting many northern and central parts of the country, according to MetService.

"There is some uncertainty regarding the location and intensity of heavy rain," a MetService spokesperson said.

"There is low confidence that a heavy rain warning will be required for Northland, northern Auckland including Great Barrier Island, Coromandel Peninsula and Western Bay of Plenty.

A complex low pressure system is likely to cover New Zealand on Wednesday, while an associated low is forecast to deepen east of the South Island later in the day.

"In the North Island, [on Wednesday],  there is low confidence that a heavy rain warning will be required for Coromandel Peninsula, Western Bay of Plenty, northern Gisborne/Tairawhiti and parts of Taranaki - mainly about the mountain.

"In the South Island, there is low confidence of a heavy rain warning for Tasman, and low confidence of warning amounts of southerly rain for parts of Canterbury and southeastern Marlborough."

MetService said additionally, there is low confidence that southerly winds could reach severe gale later in the day on Wednedsay about exposed parts of coastal Canterbury (including Banks Peninsula) and the Kaikoura Coast.

On Thursday, May 1, a deep low east of central New Zealand is forecast to move towards the Chatham Islands, with a strong wet southerly flow affecting central parts of the country.

"There is low confidence of warning amounts of southerly rain for parts of Canterbury and southeastern Marlborough in the morning, and low confidence that south or southwesterly winds could reach severe gale about exposed parts of coastal North Canterbury (including Banks Peninsula), the Kaikoura Coast, Wellington and southern Wairarapa."

On Friday, a trough is forecast to move across the central and upper North Island, while a ridge of high pressure builds over the South Island.

"There is minimal risk of severe weather on Friday."