Winter's bitter cold set to return

New Zealand remains firmly in the grip of winter, with more snow expected for much of the country this weekend. Photo / Murray Jones

A cold outbreak - rivalling that which dumped snow across the country last month - is on the way, MetService warns.

On Saturday, a low is set to move away to the east of northern New Zealand, allowing a colder southerly flow to take its place.

Weatherwatch.co.nz says the predicted possible polar blast lies in the control of an extremely large high building over Australia.

Head weather analyst Philip Duncan said they were very confident that a snow storm is brewing but still remain somewhat divided as to whether or not the bulk of the snow and wind will hit the mainland or hit further east over the Pacific Ocean and Chatham Islands.

Mr Duncan said it all comes down to the positioning of this high.

"It's not too often you see a high stretching from Antarctica to the tropics. This is of serious concern but if the high widens - and stretches further east - it will push the snowy weather east of the country".

He said it is far too close to populated areas to dismiss but said the models aren't yet in full agreement.

He added that while the system definitely has the potential to bring snow to sea level, the incoming high could affect the chances of snow to sea over New Zealand, indicating the majority of the energy may be out to the east.

"The high just has to change shape in a small way and it's the difference between a memorable snow storm and a complete non-event".

Earlier, MetService forecast temperatures to dip on Saturday night as the cold front moves over the south of the South Island, bringing snow down to sea level from southern Fiordland across to the Otago Peninsula.

The Antarctic outbreak will then move up the country, reaching the lower North Island by Sunday night.

MetService says "significant snowfalls along with bitterly cold south to southwest gales" can be expected to spread up the east of the South Island to reach Wellington and Wairarapa Sunday night, and moving further north on Monday.

Another surge of cold air in the south and east of the country on Monday will eventually spread the cold over the remaining western and northern regions of the North Island.

MetService warned the snow in South Island and southern, central and eastern areas of the North Island is likely to disrupt traffic, and farmers are advised to take necessary precautions.

- HERALD ONLINE