State Highway 8 was closed for several hours today between Tarras and Omarama (Lindis Pass) and further north between Fairlie and Lake Pukaki, owing to snow.
NZ Transport Agency Waka Kotahi (NZTA) has advised that both sections have now fully reopened, but motorists are urged to take care.
The cold snap brought a dusting of snow to hills around Dunedin on Tuesday morning.
Inland, the Danseys Pass Road is closed from the gates past the hotel owing to snow and ice on the Waitaki side, and the Crown Range Road is open but chains must be carried. The Queenstown Lakes District Council says crews have set up checkpoints to ensure vehicles abide by this rule and signage has been set-up either side of the hill.
MetService road snow warnings were in place for several southern highways overnight, including Dunedin's Northern Motorway (SH1), but these were due to expire at 7am. However, NZTA still has area warnings in place for SH1 north of Dunedin, SH87, SH85 and SH94.
"Drivers should take extra care when travelling through these areas."
Roading authorities earlier warned that frosty conditions forecast for the next few days will create dangerously icy conditions.
MetService meteorologist Katie Hillyer said the heaviest snow fell to the lowest levels around Fiordland and Southland yesterday, and, to a slightly lesser degree, it also fell in Central Otago and lower parts of the southern lakes.
"All of this came from a cold front that is currently moving up the South Island, and in behind that cold front, the temperatures are dropping with some cold air that's being brought straight from the Southern Ocean.
"So, we've got a mixture of good moisture with rain over these areas, and then gradually lowering temperatures, which is driving that snowfall further down towards lower levels."
She said snow fell to about 200m in Fiordland, about 300m in many parts of Southland, 300m-400m around Central Otago, and about 400m in the southern lakes area.
While more snow was forecast, she said it wasn't going to be "amazing accumulations".
"But people will likely wake up to a white dusting on the hills around Dunedin, down to about 400m, and maybe some snow flurries a little bit lower that won't settle."
The snow was also expected to continue overnight in Southland and Central Otago until about 8am today.
Ms Hillyer said the snow was welcomed at skifields across the southern regions.
"It's definitely been a good top-up. There’s been some reasonable accumulations, and it definitely doesn't hurt to prolong the ski season."
However, NZTA system manager Mark Pinner said very frosty conditions were expected over the next few days and warned drivers of icy roads.
Temperatures will drop as low as -2°C across much of Otago and parts of Southland overnight, for much of the remainder of this week.
"Our crews will be out and ready to clear snow and lay grit or a de-icing agent on icy roads.
"If conditions are considered bad enough, temporary speed reductions or road closures are also possible.
"We want to remind motorists to drive with care and to the conditions — including being visible, reducing speed, adjusting the travelling distance behind other motorists and avoiding sudden braking or turning movements."
He urged drivers to plan ahead and take extra time.
- additional reporting ODT Online
