A trough with embedded rain-bands will move eastwards over New Zealand on Sunday.

As it moves into the area east of the North Island on Monday, a deepening low is expected to develop east of the country bringing a period of strong south or southwest winds to northern and central New Zealand, says the latest update from the MetService.

"As the trough moves across the country on Sunday, there is moderate confidence of northerly rainfall amounts reaching warning criteria about the central North Island from Taranaki and western Waikato across the Central High Country to eastern Bay of Plenty.

"There is a low confidence of warnable northerly rainfall amounts about the northern North Island from remaining parts of Waikato and western Bay of Plenty northwards. Note a Heavy Rain Warning and Watch covering the moderate risk about the Central North Island was issued on Friday morning.

"There is also low confidence of warnable amounts of northwesterly rain on Sunday morning, and low confidence of southerly rain reaching warning criteria about northern Hawke's Bay and southern Tairawhiti/Gisborne on Monday and Tuesday.

"Additionally, a period of strong south or southwest winds is expected to affect northern and central New Zealand on Monday and Tuesday.

"There is moderate confidence that the wind could reach severe gale about northern Hawke's Bay and Gisborne for a time later Monday and early Tuesday, and low confidence for many other parts of the North Island and the Marlborough Sounds during the same period.

"A ridge of high pressure should then move across New Zealand later Tuesday and Wednesday, ahead of another trough moving onto the South Island late Wednesday."