The warnings from the forecaster, issued about midday, say snow may briefly affect the motorway around midday tomorrow, and 1 to 3 cm could settle near the summit. Lesser amounts were possible to near sea level.
Road snow warnings are also in place for the Lindis Pass (State Highway 8), Haast Pass (SH6), the Crown Range Road and the Milford Road (SH94).
Both the Milford Road and the Crown Range Road were closed overnight owing to snow. The Crown Range Road has reopened but chains must be carried, the Queenstown Lakes District Council says. The Milford Road remains closed.
There is also a heavy snow warning for Fiordland overnight and tomorrow, and heavy snow watches for parts of Central Otago, the Queenstown Lakes District, Clutha and Southland tomorrow.
The warnings come as the Southern Lakes hunker down for a weekend of wild, wintry weather.
MetService says a "barrage of fronts will continue to move in from the west, bringing periods of heavy rain to western parts of both islands".
"Heavy swell can be expected for these areas too. Very cold Antarctic air spreads northwards over the South Island during Saturday and snow is likely to low levels."
Forecasts were earlier predicting snow from today, down to 500m from Saturday, and possibly continuing until Tuesday. MetService's update now says it could be 400m in some inland areas.
"It’s really a combination of that moisture coming in from the west, plus that cold air coming up from the south that are perfect ingredients to make some snowfall," MetService meteorologist John Law said.
Conditions were looking to be "pretty unsettled" across the alpine passes for the next four days. Strong winds were forecast for the weekend and a heavy snow watch was in a place for the region as well, Mr Law said.
The news of snow caused skifields to rejoice ahead of scheduled opening days next week.
Coronet Peak ski area manager Nigel Kerr said while the mountain received a decent 20cm yesterday, it was expecting "a significant weather event such that we haven’t seen at Coronet Peak in quite a few years" over the course of the weekend.
"It’s really building up. We’ve had guns on and off ... it’s cold but we can’t complain — it’s a good problem to have."
Across the basin, the Remarkables "turned the corner for winter", receiving about 15cm of snow yesterday, ski area manager Ross Lawrence said.
"[We’ll get] another flush through tonight ... we welcome any of it and all of it and it’s starting to settle over the top of tussocks and bury them, which is great."
Queenstown Airport operations general manager Todd Grace assured travellers the airport would not grind to a halt in the event of snow.
"It will be the airlines ultimately making the decision about operating into the airport ... but we have a team here that will be on stand-by all through the night to make sure there’s no build-up on us and keep the runway good and operational."
Road travel might be a different story. Waka Kotahi NZ Transport Agency journey manager Tresca Forrester warned travellers restrictions and closures were likely in the southern alpine passes.
She said highway patrols were prepared for the weather. Motorists were advised to carry chains, pack warm clothes and food and keep up to date with weather forecasts.
- Aspen Bruce & Lucy Wormald & ODT Online
