MetService has issued a road snowfall warning for the Desert Road - State Highway 1.

Snow is expected about higher parts of the road until late afternoon today, and one to two centimetres of snow may settle near the summit, with lighter flurries above 800 metres.

The snowfall warning is valid for five hours from 11am to 4pm, today, Saturday, September 30.

Severe Weather Oulook for New Zealand this week

MetService has also issued a Severe Weather Outlook which is valid from Monday October 2 to Friday October 6.

"An intense trough moves east across the country on Monday bringing severe gales to parts of the lower North Island and much of the South Island,' says a MetService forecaster.

"Heavy rain is likely for the west coast of the South Island."

Westerly gales for the north of the North Island today. Severe weather returning to southern and central parts of the country on Monday.

Strong winds associated with a departing trough will persist about some northern areas of the North Island until Saturday evening.

Another broad trough is expected to bring strong winds to southern and central parts of the country on Monday, with brief heavy rain for the west of the South Island.

Watches for severe gales and heavy rain are in force.

Heavy Rain Watch
Area: Buller
Valid: 6 hours from 8:00am Mon 2 Oct to 2:00pm Mon 2 Oct
Forecast: Periods of heavy rain. Rainfall amounts may approach warning criteria about the ranges.

Area: Westland
Valid: 9 hours from 3:00am Mon 2 Oct to 12:00pm Mon 2 Oct
Forecast: Heavy rain. Rainfall amounts may approach warning criteria about the ranges.
Note, this Watch may be upgraded to a Warning closer to the time.

Area: Fiordland
Valid: 7 hours from 1:00am Mon 2 Oct to 8:00am Mon 2 Oct
Forecast: Periods of heavy rain. Rainfall amounts may approach warning criteria, especially about the ranges.

Strong Wind Watch
Area: Northland
Valid: 12 hours from 9:00am Sat 30 Sep to 9:00pm Sat 30 Sep
Forecast: Westerly quarter winds (west to northwest at first, then west to southwest from late Saturday morning) may approach severe gale in exposed places.

Area: Auckland including Great Barrier Island, and Coromandel Peninsula
Valid: 12 hours from 9:00am Sat 30 Sep to 9:00pm Sat 30 Sep
Forecast: Westerly quarter winds (west to northwest at first, then west to southwest from late Saturday morning) may approach severe gale in exposed places.

Area: Marlborough Sounds, Wellington, Wairarapa, Tararua District and Hawke's Bay south of Hastings
Valid: 12 hours from 6:00am Mon 2 Oct to 6:00pm Mon 2 Oct
Forecast: West to northwest winds may approach severe gale in exposed places.
Note, this Watch may be upgraded to a Warning closer to the time.

Area: Canterbury Plains including Banks Peninsula, coastal Marlborough south of Ward
Valid: 12 hours from 6:00am Mon 2 Oct to 6:00pm Mon 2 Oct
Forecast: Northwest winds may approach severe gale in exposed places.

Area: Inland Fiordland, Southland and Clutha
Valid: 12 hours from 12:00am Mon 2 Oct to 12:00pm Mon 2 Oct
Forecast: Northwest winds may approach severe gale in exposed places.
Note, this Watch may be upgraded to a Warning closer to the time.

Area: Canterbury High Country
Valid: 15 hours from 3:00am Mon 2 Oct to 6:00pm Mon 2 Oct
Forecast: Northwest winds may approach severe gale in exposed places.
Note, this Watch may be upgraded to a Warning closer to the time.

Area: Otago excluding Clutha
Valid: 12 hours from 3:00am Mon 2 Oct to 3:00pm Mon 2 Oct
Forecast: Northwest winds may approach severe gale in exposed places.

Watches no longer in Force
Strong Wind Watch lifted for Tararua District, and Hawke's Bay south of Hastings: The threat of winds reaching severe gale has passed and the Watch is lifted.

Strong Wind Watch lifted for The ranges of Marlborough and Canterbury between Ward and Waikari: The threat of winds reaching severe gale has passed and the Watch is lifted.

The week ahead

Watches for severe gales and heavy rain have already been issued.

A ridge of high pressure moves onto New Zealand on Tuesday, but northwesterlies spread onto the South Island on Wednesday.

"On Monday there is high confidence that severe northwesterly gales will affect coastal Marlborough, Canterbury, Otago, Southland and Fiordland.

"There is low confidence in severe northwest gales for Nelson and the remainder of Marlborough. There is a high confidence that severe northwesterly gales will affect Wellington, Wairarapa and Hawkes Bay south of Hastings.

"There is high confidence in warning amounts of rain for Westland but moderate confidence in warning amounts of rain for Fiordland and Buller."

Northwesterlies strengthen for a time over the lower South Island on Wednesday and MetService says there is low confidence in severe northwest gales for Fiordland and Southland then.