State Highway 87 has closed and a "handful" of vehicles are stranded on Crown Range Rd as snow starts to settle in parts of the South where warnings are in place for possible heavy falls..
NZTA Waka Kotahi made the call at about 5.20pm, cutting off Middlemarch.
It was joined by SH85 (Pigroot) between Palmerston and Alexandra at about 8.15pm.
Snow is also falling in Central Otago and particular caution has been advised in Maniototo and Manuherekia areas.
The Crown Range Rd was open at 5.45pm but webcams showed heavy snow had fallen at the summit over the previous hour.
A police spokesman said at about 7pm that they had received calls about "a small handful" of vehicles stranded on Crown Range Rd by the snow.
The spokesman believed QLDC contractors were working to clear the road so they could proceed with their journeys.
In a post to social media at 7.45pm, QLDC advised the road would remain open but chains were required on the route.
"The road is open, but the conditions are difficult to drive in. We'll update this status as things progress," the post read.
Elsewhere, Canterbury weather watchers have posted photos and videos on Facebook of snow at Mt Cook Village and at Mt Hutt skifield.
MetService this morning updated its severe weather alerts and issued an orange heavy snow warning for inland Canterbury, from the Rakaia River southwards from 3pm on Friday to 6am on Saturday.
MetService says to expect 10 to 20 cm of snow to settle above 500 metres, with lesser amounts down to 300 metres.
The forecaster said the snow could disrupt travel and cause damage to trees and powerlines. It urged people to prepare for freezing temperatures and possible power outages."If you must travel, drive cautiously, and ensure you have snow chains, sleeping bags, warm clothing, and emergency items."
An orange heavy snow warning issued for Central Otago was downgraded to a heavy snow watch, from 2pm to 8pm today, and a heavy snow watch is also in place for the Queenstown Lakes District, from 3pm to 10pm today.
NZTA Waka Kotahi has warned of snow on State Highway 6 between Kingston and Lumsden, SH94 between Lumsden and Milford Sound, SH85 between Kyeburn and Alexandra and SH8 between Alexandra and Raes Junction.
Ice and snow are also possible SH90 between Tapanui and Raes Junction.
Danseys Pass Rd was closed from the gates past the Danseys Pass hotel at about 5.30pm due to snow.
Freezing start to day
At 7am, MetService's website showed Mosgiel as officially the coldest centre in the country, on -5C. Alexandra was on -2.5C, and Queenstown -1C.
Dunedin was on 3C, only one degree less than the warmest places in the South Island - Nelson and Westport on 4C.
At 10.45am Mosgiel was still shivering, on -1.5C.
Non-official weather station data on the MetService site showed -7C at Tekapo at first light, and both the Central Otago District Council and the Queenstown Lakes District Council said temperatures of -6C had been recorded.
The freezing conditions prompted Southern Police to issue a warning of black ice on Southland roads and to urge motorists to take "extreme care".
They said they had already attended one black-ice related crash this morning and were aware of another.
"Thankfully no one has been injured but we want to ensure everyone gets to their destination safely."
MetService Meteorologist Lewis Ferris said the heaviest snowfall was expected in high, inland areas.
"These areas do look most likely to see some heavy snow throughout Friday, running into the night time and maybe just tipping over into Saturday as well," he said.
Temperatures across the southern half of the South Island were expected to dive into the negatives, and remain low for most of the weekend.
"A lot of people will have noticed a real chill to the air," Ferris said.
"It looks like the South Island, even parts of the North Island, will feel the chills through the weekend. Some places even into the middle of next week, especially around Central Otago, places like Alexandra, might be fighting to get out of those negatives even through the daytime," he said.
Farmers brace for snow
The sub-zero temperatures and potential snow are bringing added stress to farmers and their livestock.
In Tapanui - near Gore - Federated Farmers' Otago president Luke Kane has been getting his farm and animals ready.
He told Morning Report the drop in temperatures and heavy snow didn't come as a surprise for this time of the year.
"It is winter after all. We normally would anticipate two to three of these storms for us throughout the winter and this may be the first one."
Preparation was key when these types of snow storms hit, including putting out few extra hay bails, utilising shelter and making sure staff were safe and well fed, Kane said.
Road snow warnings
Road snowfall warnings are in place for Dunedin's Northern Motorway (SH1) from 1pm to midnight on Friday, the Crown Range Road from 4pm to 10pm on Friday, Haast Pass (SH6) from 8pm to midnight Friday, Lindis Pass (SH8) from 4pm today to 1am on Saturday, the Milford Road (SH94) from 4pm to 9pm on Friday, Lewis Pass (SH7) from 5pm on Friday to 9am Saturday, Arthur's Pass (SH73) from 4pm Friday to 8am Saturday, and Porters Pass (SH73) from 4pm Friday to 8am Saturday.
- APL/additional reporting RNZ
