Wild weather: Snow closes roads, forces evacuations at Mt Ruapehu

White-out conditions at Mt Ruapehu have forced the evacuation of dozens of people from the slopes today.

A blizzard that hit the mountain had dumped stacks of snow on the mountain's Whakapapa and Turoa skifields overnight - and left around 30 people trapped in nearby lodges.

Ruapehu Alpine Lifts spokesperson Anna McLaren said the visitors, who had stayed on the mountain overnight, had to be escorted by staff down to Ohakune and Whakapapa village after operators closed access roads this morning.

All of the trapped visitors were believed to have all been accounted for.

"I'm just waiting to hear back from the guys but I believe they have it all in hand - it was just a process of getting people down safely."

McLaren said the blizzard was "huge", leaving cars buried in snow up to their windows.

"It was a goodie - it's been heavy snow, and we had about 30cm on both sides of the mountains... so it's been white-out conditions."

Earlier, snow closed the Desert Road and raised avalanche risk at mountains around the country, with warnings of blizzard-like conditions predicted to hit south of the volcanic plateau today.

Heavy falls are expected down to 700m in Taumarunui and Taihape, with up to 10cm of snow forecast to arrive by this afternoon.

A warning issued by the MetService after 8am said the snow could cause disruption to traffic, particularly in exposed places.

Snow warnings have been lifted in the South Island, however three roads are closed due to weather, with motorists warned to watch for ice, and carry chains.

Heavy showers, thunder and hail are forecast for Auckland, with conditions across the country expected to be cold today, and rainy for the rest of the week.

As well as the Desert Road, State Highway 93 from Mataura to Clinton is closed because of snow.

The road from Te Anau to Milford Sound is also closed in places. State Highway 6 between Haast and Makaroa has been closed because of a slip.

There are five road warnings in place for the Southland district because of snow and ice, including black ice on State Highway 6 between Queenstown and Cromwell.

Other warnings are in place because of snow and ice around Cromwell, Arthur's Pass, Lindis Pass, Lewis Pass, Mosgiel, Palmerston, Canterbury, Takaka, near Hanmer, near Nelson and on the West Coast. Drivers are also urged to take care on the Napier-Taupo Road.

Further, the New Zealand Mountain Safety Council reported the risk of avalanches was "considerable" at areas including Tongariro, Taranaki, Nelson Lakes, Arthur's Pass, Craigieburn Range, Aoraki/Mt Cook, Queenstown, Wanaka and Fiordland.

A warning level of "considerable" meant conditions were dangerous and "conservative decision making" was essential.

In the Tongariro region, the safety council-operated New Zealand Backcountry Avalanche Advisory, issued yesterday, reported there had been "substantial loading" of snow in eastern areas.

"We are in a very active weather cycle with high winds and increasing amounts of snowfall, during this period the rapid development of wind slab coupled with inclement weather will make route finding and avalanche assessment difficult," it stated.

"During the development of this slab there is a very good chance that a single skier could trigger an avalanche up to 1m deep."

The risk at Ohau and Two Thumbs in Mackenzie Country was "moderate", and "low" at Mt Hutt.

The MetService says a trough crossing New Zealand tomorrow will bring rain to the west, and is likely to bring more snow to the South Island.

"Thunderstorms are possible over the upper North Island," it said.

"Snow showers may also fall on the lower hills of Southland and Otago."

The forecast said on Tuesday, a ridge will move slowly east across New Zealand.

On Wednesday or Thursday another trough risks bringing heavy rain to Mt Taranaki, the Tararua Range and the ranges of Nelson, Buller and Westland.