MetService's snowfall warning for the Desert Road on Saturday is extending into today.

"A period of snow is likely above 900 metres from Sunday morning to Sunday evening, and 3 to 5 cm may settle on the road," says a MetService spokesperson.

The warning is valid until 7pm today, Sunday July 2.

"Showers are expected to turn to snow above 1000 metres and 1 to 2 cm may settle on the road," says a MetService spokesperson.

A strong, unsettled southwest flow brings an extended period of showers to many parts of New Zealand, especially in the north, south and west.

On Monday morning, snow is expected to continue to fall to low levels in the south of the South Island and there is high confidence that some places could see warning amounts of snow above 300 metres in Fiordland, Southland including Stewart Island, Clutha, Dunedin and parts of inland Otago.

Severe Weather Warnings and Watches are in force for these areas. Snow is also expected to affect higher roads and passes along the Main Divide further north, and in parts of the North Island.

There is low confidence that west to southwest winds could rise to severe gale on Monday about the North Island, Nelson and the Marlborough Sounds, and coastal parts of Canterbury, Otago and Southland.

Confidence is now considered moderate that severe west to southwest gales could affect coastal Otago and Southland on Tuesday and Wednesday.