A cooler showery west to southwest flow will be affecting New Zealand on Tuesday.

The MetService expects this to bring snow to parts of the South Island, especially the mountain passes.

"A front is expected to move northeast across the the country from Tuesday afternoon to Wednesday morning, followed by cold southerlies."

Fresh snow fell at Ruapehu on the weekend with more expected over the next couple of days, according to locals.

"A ridge of high pressure should build over New Zealand late Wednesday," says a MetService spokesperson.

A subtropical low is forecast to approach the far north of the North Island late Thursday, then move slowly southeast across the North Island during Friday, bringing rain to many areas of the North Island.

"On Tuesday, there is low confidence of west to northwest winds rising to severe gale in exposed places of Hawke's Bay south of Hastings and Wairarapa north of Masterton, including the Tararua District.

"There is low confidence of warning amounts of rain in Northland and Great Barrier Island late Thursday and Friday, and about Gisborne on Friday."