Much of Otago, Southland and Queenstown Lakes, including Dunedin, is under a heavy snow watch from this evening into tomorrow morning.
Snow is expected to near sea level in Dunedin, MetService says.
MetService meteorologist Alex Holden said much of Otago had heavy snowfall warnings for 300m above sea level.
"It is fairly unusual to get snow this low and this intense at this late time of the year."
The worst of the cold snap, which could bring sub-zero temperatures to parts of Otago and "low single-digit" figures for Dunedin, would occur tomorrow morning, he said.
"A lot of people will wake up to snowy white caps on the mountains."
But the cold snap would be "short and sharp", he said, with conditions rebounding on Saturday and Sunday, although he expected Saturday to be a "bit cloudy and miserable".
"It is not unlikely we will get another cold front very shortly. Whether it will be as intense as this one is hard to say."
Winds affect flights
Gale-force winds have forced the cancellation of flights at Wellington Airport and blown over a truck in Canterbury as wild weather bringing snow and heavy rain marches up the island.
On the country’s roads police have closed State Highway 1 north of Kaikōura because of high winds in the area. They asked motorists to avoid the area.
A Wellington Airport spokesperson said an Air New Zealand flight from Hamilton made two attempts to land in Wellington this morning but was unable to due to the wind.
It was diverted to Palmerston North, which means NZ5347 from Wellington to Christchurch has had to be cancelled.
Another Air NZ flight from Christchurch was unable to land in the capital after two attempts and has diverted to Auckland.
Waka Kotahi NZ Transport Agency reported a truck had tipped over at the intersection of SH7 in Canterbury and motorists there should expect delay
Road snow warnings
Dunedin to Waitati highway (SH1)
Period: From 10pm on Thursday until 6am on Friday
Snow may briefly affect the road for a time tonight and early on Friday morning, and 1cm to 3cm may settle on the road near the summit. Note, another burst of snow is possible later on Friday, and this warning may be extended.
Milford Road (SH94)
Period: From 3pm on Thursday until 6am on Friday
Rain forecast to turn to snow near the Tunnel this afternoon, then gradually lower to near sea level early on Friday morning. Expect 10cm to 15cm of snow to settle on the road above 800 metres, with lesser amounts down to near sea level.
Crown Range Road
Period: from 9pm on Thursday until 5am on Friday
Snow forecast to briefly affect the road for a time tonight and early on Friday morning, and 2cm to 4cm may settle on the road.
Lindis Pass (SH8)
Period: from 10pm on Thursday until 6am on Friday
Snow expected to briefly affect the road for a time tonight and early on Friday morning, and 1cm to 3cm may settle on the road.
Haast Pass (SH6)
Period: From 9pm on Thursday until 6am on Friday
Rain set to turn to snow tonight. Expect 2cm to 5cm to settle on the road near the summit, with lesser amounts down to 300 metres.
Arthurs Pass (SH73)
Period: From 12am to 8am on Friday
Rain expected to turn to snow tonight. Expect 4cm to 8cm of snow to settle on the road above 800 metres, with lesser amounts at lower levels.
Lewis Pass (SH7)
Period: From 1am until 2pm on Friday
Rain is forecast to turn to snow tonight. Expect 4cm to 8 cm of snow to settle on the road above 800 metres, with lesser amounts at lower levels.
