Weather: 'Still a good chance' of snow in Christchurch, roads closed as snow falls in South Island, Canterbury, Otago as polar blast arrives, Wellington CBD forecast to get snow
The temperature in Wellington dropped 4.8 degrees in an hour this afternoon, while snow is falling in Canterbury and several roads have been closed as a winter blast settles over much of Aotearoa.
Waka Kotahi NZTA says State Highway 87 between Kyeburn and Outram is closed due to snowfall.
Snow started to fall in Christchurch this evening, quickly turning to heavy sleet. MetService said, "there's still a good chance that it will snow in Christchurch later tonight. Snow is still a good bet for Banks Peninsula, more so than the city, but it's not too far away - it's still well and truly on the cards."
"Queenstown has a good white coverage on the ground, but the grass is still green in Christchurch."
A blast of cold air coming "straight from Antarctica" has brought snowfall in the South Island this morning as Wellington CBD will have its best chance of snow in a decade.
MetService's hourly temperature observations reveal that the capital plunged from 13.1 to 7.3 degrees at 2pm. For anybody still waiting for snow around the city, the national forecaster advised it is most likely to come early tomorrow morning: "If you sleep in you'll probably miss it!"
MetService said a "quick bout of snow" had just passed through the Canterbury town of Timaru, where the temperature dropped 6 degrees in half an hour.
Shortly after 8am MetService issued a heavy snow warning for the far south of the South Island and Banks Peninsula.
"An intense cold outbreak spreads northwards over the country today and on Thursday, bringing unseasonably low snow to the South Island and the lower North Island.
"South to southwest gales are also possible, especially in the east from Invercargill to Wellington.
"Snow is likely to affect many parts of the South Island and lower North Island. Heavy snow watches remain in force for many areas and warnings have been issued for the far south of the South Island and Banks Peninsula. Note that significant disruptive snow is also likely to affect many other areas.
"People are advised to proceed with caution and keep up to date with the latest MetService forecasts and advice from the NZTA. This event will bring significant impacts to transport, livestock and crops."
The heavy snow warning for Southland, Stewart Island, Clutha, Dunedin, Central Otago south of Alexandra, the Southern Lakes District south of Queenstown, and Fiordland from Te Anau southwards is in place from 9am today yo 9am tomorrow with 20cm to 30cm of snow above 200m.
It may already be cold with snow to near sea level but there is colder air moving up the country throughout today.
Traffic cameras captured early morning snow falling in Fairlie, Canterbury as snow arrived in the South Island.
Travel warnings
Several roads are closed and others could close as snow continues to fall across the South Island.
From Wednesday evening through to Thursday evening snow showers will affect the Desert Road, Remutaka Hill Rd and Crown Range Rd.
The Desert Rd could see 3 to 5cm of snow, as could the Remutaka Hill Rd. The Crown Range Rd is already being affected by snow flurries. In addition to snow that has already accumulated, people can expect a further 1 to 2cm today and another 1 cm or so tomorrow.
The Dunedin to Waitati Highway will see a total of 6 to 9cm of snow today and then a further 4 to 6cm on Thursday.
Lewis Pass will be affected by snow between 10am and 10pm today with 1 to 2 centimetres falling this morning and a further 3 to 5cm into the evening, and Arthur's Pass will see a further 2 to 4cm in addition to what has already fallen.
Porters Pass will have snow showers this afternoon with a forecast of 3 to 5cm of snow on top of what has already fallen and Haast Pass could be "briefly" affected by snow showers this morning and afternoon.
Lindis Pass will be impacted by 26 hours of snow flurries between Wednesday morning and Thursday afternoon and Milford Rd will see 3 to 5 extra cm of snow on top of what has fallen already.
Some snow flurries may affect the road tomorrow and 1 or 2cm more may accumulate south of Lake Gunn.
Caution is required on SH93 between Clinton to Mataura due to winter driving conditions. Further forecast snow may affect state highways and local roads throughout the South Island. Please take extra care on all roads and plan ahead if you intend to travel on the network today/tonight. CLOSED • SH8 Tarras to Omarama (Lindis Pass) - Snow and Ice OPEN CAUTION • SH8 Cromwell to Tarras - Snow and Ice • SH93 Clinton to Mataura - Snow OPEN • SH73 Arthurs Pass to Otira - Snow • SH73 Springfield to Caste Hill has vehicle restrictions in place. Chains are essential, and it is closed to towing vehicles. • All other State Highways remain open SH2 Kaitoke to Featherston (Remutaka Hill) A strong winds warning is in place between Kaitoke and Featherston (Remutaka Hill), extra care is required especially for lighter or high-sided vehicles and motorcycles.
The snow has closed off State Highway 73, Arthurs Pass to Otirā.
Waka Kotahi NZ Transport Agency said: "Further forecast snow may affect state highways and local roads throughout the Canterbury and Otago regions."
Motorists are being warned to take extra care on the roads as a result and are urged to plan ahead if intending to travel today or tomorrow.
Livestock in Glentunnel, a village in the Selwyn District, have already been dusted in snow. MetService warned earlier in the week the unseasonably cold temperatures had potential to damage crops and stress animals.
Severe weather watches
MetService has issued a number of heavy snow watches in several parts of the country.
People in Wairarapa, including the Tararua Range south of Mount Bruce, and the eastern hills of Wellington are advised of a heavy snow watch in place from 10pm to 4pm tomorrow.
"Snow may lower to near sea level during this time and amounts could approach warning criteria above 200m," the MetService said.
There is also a watch over Marlborough south of the Clarence River, the Canterbury high country and foothills, North Otago, Central Otago and Alexandra northwards - as well as the Lakes District from Queenstown northwards.
The heavy snow watch is in place until midnight tonight.
The weather authority is advising people in these areas that snowfall amounts could approach "warning criteria" above 400m.
The Canterbury coast and plains, including Christchurch and Banks Peninsula, has a heavy snow watch for the 38 hours that started at 1am today, until 3pm tomorrow.
Again, people are being told that snowfall amounts may reach warning criteria above 400m.
"Then from 6pm [today] to 3pm [tomorrow], snow showers may lower to near sea level and snowfall amounts could reach warning criteria to near sea level - especially about Banks Peninsula."
MetService advises that heavy snow watch might be upgraded to a warning.
A little science behind the snow (and rain).
The air ~1500 m above is forecast to be about -9°C. Meanwhile, the ocean is about +10°C. This creates instability.
Winds are aligned in the vertical ↕️ which focuses moisture into a thin band.
Weather experts say the Wellington region is set to get large amounts of snow as a polar blast settles over the capital this evening and into tomorrow morning.
MetService meteorologist Jesse Owens said: "The worst of that [snow] will be in those eastern regions, so we'll expect larger amounts of snow to low levels."
The Tararua and Rimutaka Ranges will likely be covered, with around 5cm to 8cm of snowfall forecast for the summit of the Rimutakas.
A little science behind the snow (and rain).
The air ~1500 m above is forecast to be about -9°C. Meanwhile, the ocean is about +10°C. This creates instability.
Winds are aligned in the vertical ↕️ which focuses moisture into a thin band.
"Anywhere in Wellington you could see snow. This is our best chance in a long while to see some snow. We're expecting down to 200 to 300 metres tonight and overnight tomorrow morning. It could get to sea levels."
Weather authorities have described the wintry blast as an intense, cold outbreak that will spread northwards over the country this week.
Snow is likely to affect many parts of the South Island and lower North Island, in particular, with temperatures set to drop and heavy snow watches in place.
Snow in October
Owens said the conditions were unusual for this time of year even though spring weather could be very changeable.
"We don't see it often and not in October. It's very rare and it is unusual to see an outbreak this cold this late in the year."