A low is expected to develop in a trough east of the North Island on Tuesday and slowly move south over the next few days.

"This low could bring heavy rain to eastern areas of New Zealand, but there is a high degree of uncertainty regarding its position and movement," says a MetService spokesperson.

"There is low confidence that a rainfall warning will be needed for Tairawhiti/Gisborne, Hawke's Bay and Wairarapa on Tuesday and for eastern Marlborough and North Canterbury on Wednesday.

"For Tairawhiti/Gisborne and northern Hawke's Bay in particular, there may be further impacts regardless of whether a warning is issued due to the extremely wet conditions that have been experienced there recently."

MetService says on Thursday, a strong southwest flow should move onto New Zealand.

"There is low confidence that winds will reach severe gale force about Northland and Auckland on Friday."

On Friday, an approaching front may bring heavy rain for Fiordland and some snow is possible about the higher roads of Southland and Otago at night.

"At this stage, it appears unlikely that warnings will be needed on Friday for the rain and snow."