Dangerous black ice is expected on southern roads tomorrow morning, and drivers are being urged to take extreme care.

An overnight snowfall forced the closure of several schools, roads and services in Dunedin today. Snow fell to sea level, making driving conditions tough for those trying to get to work. And despite most motorists reaching their destination, police say some were not so lucky. Courtesy Ch39 Dunedin

Snow, freezing temperatures and clearing overhead conditions mean many Otago and Southland roads will probably be affected by severe icing, the NZ Transport Agency warned.

Timelapse: Snow hits Dunedin

Schools have shut their doors and several major roads are closed as a wintry blast brings snow falls to sea level from Invercargill to Dunedin. Timelapse video courtesy WickedNetworks/YouTube taken from the public traffic camera on Highgate in Dunedin.

NZTA's Otago-Southland Highways Manager, Ian Duncan said the wintry storm that swept through both regions had now been followed by clearing, cold weather, making black ice a real danger. This form of ice was especially treacherous because it could not be seen.

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"Winter roads demand winter driving and motorists can keep themselves safe by lowering their speeds, increasing their following distances, and taking extra care when cornering."

Mr Duncan said icy conditions meant trips took longer and motorists should allow more time and consider departing later in the morning to allow ice to thaw, or leave earlier in the afternoon before ice formed.

Acting Area Commander Otago Rural Inspector Andrew Burns said the freezing conditions forecast overnight would make driving extremely difficult.

Mr Burns said it was important that anyone driving over the next 24 hours remained aware of the likelihood of black ice right throughout Otago and Southland.

The latest winter driving conditions are available at www.highwayinfo.govt.nz, or by calling 0800 44 44 49.

The final week of Autumn is going out with a bang as yet another storm in the Southern Ocean lines itself up with New Zealand this week. Unlike the weekend cold blast this one is weaker, but will bring a period of strong to gale force winds to southern and eastern areas of both islands – and late Wednesday and into Thursday a colder southerly heads north. Winter kicks off officially on Sunday – and the forecast looks mostly settled.

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