On Monday an unsettled northwesterly flow is forecast to cover the country, according to the MetService.

'An active front is forecast to move northeast over southern and central New Zealand on Tuesday, bringing a period of heavy rain to western areas, and northwest gales to exposed central and eastern places,” says a MetService spokesperson.

'Snow may also briefly affect some of the South Island passes.

'The front weakens as it moves over northern New Zealand on Wednesday, and is followed by a ridge of high pressure.”

On Tuesday, there is moderate confidence rainfall amounts will reach warning criteria in Westland, Buller and northwest Nelson, especially about the ranges.

'And some spillover is likely into the headwaters of the Otago and Canterbury lakes and rivers.”

Meanwhile, there is low confidence of warnable amounts of rain for Fiordland, the Tararua Range and Mount Taranaki.

In addition, on Tuesday there is moderate confidence of a period of severe northwest gales about exposed parts of Wellington and Wairarapa including the Tararua District, and low confidence for Marlborough, the Canterbury High Country, inland parts of Otago, Fiordland, Southland and Stewart Island.

WeatherWatch says heavy rain is expected today for the West Coast.

The weather forecast for Northland, Auckland, Waikato and the Bay of Plenty for today is for cloudy spells, with a chance of a shower mainly in the east but some areas will remain dry for much of the day. Also northeasterly winds, with highs of between 19 and 21 degrees.

The weather forecast for Saturday for the rest of the country, is as follows:

Western North Island (including Central North Island)
Sunny areas and some high cloud, Taranaki may get a shower or two from evening. Northerly quarter winds.
Highs: 16-20

Eastern North Island
Sunny areas and some high cloud, north to northeasterly winds.
Highs: 19-21

Wellington
Plenty of high cloud, northerlies pick up from late morning becoming gusty.
Highs: 17-19

Marlborough & Nelson
Cloud thickens in the morning, the odd spit or shower from afternoon, more so for Nelson, to a lesser extent Marlborough. North to northwesterly winds pick up in the afternoon.
Highs: 17-20

Canterbury
High cloud, some sun may break through at times. Rain picks up in the evening about the high country spreading from the west. North to northeasterly winds.
Highs: 16-20

West Coast
Cloudy with the odd shower developing in the morning, rain from afternoon, becoming heavy for South Westland then further north in the evening. Northeasterlies freshen.
Highs: 17-18

Southland & Otago
High cloud thickens from morning, rain spreads into the lakes district from afternoon, overnight rain for Southland. North to northeasterly winds.
Highs: 15-18