Large avalanches are possible in the backcountry this week, with more significant snowfall predicted.
The warning comes after one of a group of five was flown to hospital following an avalanche near Aoraki/Mt Cook on Tuesday.
Nick Kingstone, of the Mountain Safety Council, said the eastern side of the Southern Alps is in for more snow.
"It's great for the eastern side ski fields, but can create some very dangerous conditions in the backcountry," he told Newshub.
Kingstone said it was important backcountry users are experienced and can identify snowpack issues.
"A group of people can actually trigger an avalanche further down into the snowpack which you may or may not see on the surface."
- Weather: New maps show massive 'wave' of polar air hitting New Zealand
- Weather: Severe thunderstorm, tornado, hail warning for North Island
Snow and frost on the way
A bitterly cold weekend is in store for much of the country.
The South Island is in for widespread frosts and snow to possibly low levels east of the Southern Alps.
MetService meteorologist Andy Best told Newshub that in the north, snow may also hit the Remutaka Hill Rd, and higher Hawke's Bay roads.
"You will feel quite bitterly cold due to the wind chill factor as well as the cold air," he said.
Central Otago and Southland could also drop to a chilly -4C.
Newshub.
