Snow down to 100m tonight in southern areas as polar blast continues

It's a little chilly in Fairlie, where snow is settling. Photo/Brucie Raines

Parts of the South Island in the grip of a polar blast can expect even more snow overnight as a cold front brings freezing levels down as low as 100m, the Metservice says.

Most places above 300m in the South Island received snowfall today, but plummeting temperatures tonight could bring the snow down even lower.

Meteorologist Ravi Kandula said the front will be reaching Stewart Island about midnight and bringing low snow to the Southland and Dunedin areas.

Roads have been closing over many parts of the South Island as snow sets in. Photo/Brucie Raines

Those low freezing levels will work their way up the South Island tomorrow, and icy temperatures will reach the North Island tonight.

Extensive warnings went out earlier as much of the country is set to freeze in the snowstorm.

Those in the Wellington region may wake up in the morning to find snow on the Rimutaka Hill Road, but the real thing to watch out for will be the high winds around the south coast of the North Island.

Kandula said areas around Wairarapa and Wellington could be looking at wind gusts up to 100km/h and a mean wind speed of 50 or 60km/h.

Offshore, winds could reach "storm-force" speeds, though it wasn't expected to be quite so ferocious on land.

"Basically, the south coast is not a place to be tomorrow," Kandula said.

Those winds would "start to really ramp up" in the afternoon and evening.

Shortly after 1pm today snow began falling, though not yet settling, in the Queenstown Lakes district, with the council warning chains must be fitted for anyone driving on the roads.

Civil Defence authorities were telling people to prepare for bone-chilling conditions as the wild weather headed north.

The Queenstown Lakes District Council said there were two crashes - one on State Highway 6A near Yewlett Cres involving a truck rolling, and another on State Highway 6 near Boyd Rd.

The council said temperatures were well below freezing with ice forming on all roads, especially through shaded areas and over bridges. Freezing fog in many places was adding to hazards.

WeatherWatch's forecast team said behind the front, most places were dropping to mid to low single-digit temperatures - but things were not as cold as they could have been.

"Remember while this is a bitterly cold wintry event with severe weather potential, it's not an Antarctic storm so the air being dredged up is not as cold as it could be."

The weather also brought disruption to travel operators across the country, with flights cancelled and ferry sailings halted through to tomorrow evening due to 7m-high predicted swells in the Cook Strait.

Potentially damaging gales are also expected to whip through North Canterbury, Marlborough and Nelson tomorrow and overnight until Thursday.

Numerous road closures across the South Island have also caused headaches for motorists.

The forecast

Auckland: 8C overnight, 12C tomorrow.

Tauranga: 6C overnight, 12C tomorrow.

Hamilton: 4C overnight, 11 tomorrow.

Wellington: 5C overnight, 8C tomorrow.

Christchurch: 1C overnight, 6C tomorrow.

Dunedin: 2C overnight, 6C tomorrow.