MetService has issued a Severe Weather Warning for parts of New Zealand.

Heavy rain and snow is expected for parts of the South Island and southeasterly gales for central New Zealand, says a MetService spokesperson.

"A front, preceded by a moist northwesterly flow, is forecast to move northeastwards over the South Island during Sunday.

"This front is expected to bring a period of rain to most places, with brief heavy falls likely in the west."

Much colder southerly winds are expected to follow the front, which MetService says will bring the snow level down to around 500 metres in Marlborough, Canterbury, Otago, Southland and Fiordland.

"It's likely that several of the higher South Island roads will be affected by snow on Sunday and Monday, and high country farmers in Otago and Canterbury are advised to prepare for the potential of significant snowfall from Sunday into Monday.

A Heavy Snow Warning is in place for the Mackenzie District. This warning is valid for nine hours from 12pm to 9pm Sunday June 4.

"Expect 15 to 25 cm of snow above 600 metres, with lesser amounts down to 400 metres.

"Heavy snow may disrupt travel in affected areas and could damage trees and powerlines. Cold conditions may cause stress for livestock."

Heavy Rain Watch:

Area: Canterbury north of Arthur's Pass and Marlborough east of Awetere Valley
Valid: 9 hours from 6:00pm Sun 4 Jun to 3:00am Mon 5 Jun
Forecast: Periods of heavy rain. Rainfall amounts may approach warning criteria, mainly about the ranges.

Area: Westland south of Otira
Valid: 12 hours from 3:00am Sun 4 Jun to 3:00pm Sun 4 Jun
Forecast: A period of heavy rain. Rainfall amounts may approach warning criteria, mainly about the ranges.

Area: Fiordland
Valid: 9 hours from 9:00pm Sat 3 Jun to 6:00am Sun 4 Jun
Forecast: A period of heavy rain. Rainfall amounts may approach warning criteria.

Heavy Snow Watch
Area: Canterbury High Country about and north of Rangitata River
Valid: 9 hours from 3:00pm Sun 4 Jun to 12:00am Mon 5 Jun
Forecast: Snow may lower to 400 metres with heavy snow expected above 500 metres. Snow accumulations may approach short duration warning amounts.

Area: Central Otago about and west of Alexandra including the Queenstown Lakes District
Valid: 6 hours from 6:00am Sun 4 Jun to 12:00pm Sun 4 Jun
Forecast: Snow is expected to lower to 500 metres and snow amounts may approach short duration warning criteria, especially above 700 metres where the largest accumulations are expected.

Strong Wind Watch
Area: Taranaki
Valid: 15 hours from 12:00pm Mon 5 Jun to 3:00am Tue 6 Jun
Forecast: South to southeast winds may approach severe in exposed places.

Area: Wellington and Marlborough Sounds
Valid: 18 hours from 3:00am Mon 5 Jun to 9:00pm Mon 5 Jun
Forecast: South to southeast winds may approach severe gale at times.

Area: Nelson, Buller and Marlborough west of Wairau Valley but excluding the Sounds
Valid: 14 hours from 10:00pm Sun 4 Jun to 12:00pm Mon 5 Jun
Forecast: Southeast winds may approach severe gale in exposed places, mainly inland.

Area: Westland including the Grey District
Valid: 24 hours from 6:00am Sun 4 Jun to 6:00am Mon 5 Jun
Forecast: Southeast winds may approach severe gale in exposed places, especially inland.