A polar blast is expected to bring severe gales and snow to low levels across the southern region, including Dunedin, today.
Snow has already been reported around Queenstown, Naseby and Ranfurly, and the Milford road (State Highway 94) is closed owing to snow.
All other highways were open around 7am, but snow and strong wind warnings were in place on several roads.
MetService forecaster Gerard Bellam last night said an active cold front would "ooze up" the South Island from the Antarctic, bringing bitterly cold winds which could reach 100kmh at times.
Additionally, snow is forecast to lower to about 100m and accumulations could reach warning criteria above 200m in parts of the southern region.
"I think this will be Otago and Southland’s first significant winter outbreak of the year."
"The South Island’s going to cop the worst of it," Brandolino told The AM Show.
“The windchills are going to be brutally, brutally cold."
He said that by sunset today, windchills for the lower third of the South Island could be down to -15 degrees Celsius.
MetService's Bellam said the weather would cause hazardous driving conditions and stress to livestock around the region.
"I’m sure the farmers have taken heed with the heavy snow watch and the road snow warnings, to move stock to lower grounds."
Large south-to-southwest waves were also expected to spread northwards over coastal areas of New Zealand today and tomorrow.
"You can get waves smashing up onto sea walls and the rocks, so people around the coast should be mindful that it’s not a safe time to be fishing off the rocks."
The waves might also cause damage to roads and communities typically affected by swells from these directions, he said.
In Dunedin and Oamaru this morning, frequent showers, some heavy, would turn to snow down to 200m, and thunderstorms and hail were possible about Dunedin afternoon.
Southwesterlies, gale in exposed places, could gust to 100kmh in both places.
Conditions in the Clutha area would be similar, except snow would fall to 100m and a heavy snow watch is in place.
In Queenstown, Wanaka and Alexandra, frequent rain showers were expected to turn to snow showers this morning and would be accompanied by cold, gusty southwesterlies.
In Invercargill, showers would be sleety, but in Gore and Tapanui, there would be frequent snow showers, and heavy snow watches are in place.
Squally thunderstorms and hail were also possible in these places, and there would be strong and gusty southwesterlies.
A heavy snow watch is also in place for Fiordland (south of George Sound), where accumulations may approach warning amounts above 200m in 6-hour periods.
Mr Bellam said road snowfall warnings were in place for the Dunedin to Waitati Highway (3pm today to 7am tomorrow), where up to 4cm of snow was expected to settle on the road above 200m and lesser amounts at lower levels.
Milford Road can expect 15cm-20cm of snow to settle above 500m between 3am and 7pm today; the Crown Range Rd can expect up to 6cm to settle on the road between 3am today and 2am tomorrow; Lindis Pass can expect up to 8cm above 500m between 6am and 11pm today; and the Haast Pass is expected to receive up to 3cm of snow on the road near the summit between 5am and 2pm today.
"People are advised to keep up to date with the latest Watches and Warnings in case any changes are made, or further areas are added," he said.
The cold southwest flow would continue over New Zealand tomorrow and Wednesday, gradually easing later in the day on Wednesday, as a ridge of high pressure established itself over the country for Thursday and Friday.
- John Lewis. Photo: NZ Herald
