Get the winter woollies out again - a winter blast is on its way this week, with weather experts describing the return of bitterly cold temperatures and snow.
MetService says a sudden "Antarctic blast" is set to chill the country over the next few days, starting with a blast of cold polar air.
A period of heavy snow is expected for the south and east of the South Island as what is tipped to be an intense cold outbreak spreads northwards over the country from this evening through to Thursday.
It will bring unseasonably low snow to the South Island and the lower North Island, the weather authority says.
"Snow is likely to affect many parts of the South Island and some roads over the lower and central North Island."
A heavy snow watch will be in place in Marlborough south of the Clarence River, the Canterbury High Country and foothills, also North Otago, Central Otago from Alexandra northwards and the Lakes District from Queenstown northwards.
The watch is in place from 10pm (tonight) until about 8am tomorrow.
People in those areas are told that a brief burst of heavy snow is a possibility and snowfall amounts may approach warning criteria above 400m.
There is also a heavy snow watch in place in the Canterbury coast and Plains - including Christchurch and Banks Peninsula.
That watch starts from 1am tomorrow until 3pm on Thursday. Again, a brief burst of heavy snow is forecast from the early hours of tomorrow morning between 1am and 8am.
Locals are also being told that snow amounts may approach warning criteria above 400m.
Southland, Stewart Island, Clutha, Dunedin, Central Otago south of Alexandra, the Lakes District south of Queenstown and Fiordland from Te Ānau have are affected by the heavy snow fall watch too.
People in those parts of the country are advised the watch is in place for 38 hours from about 7pm until 9am on Thursday.
Snow warnings for roads
Snow is likely to affect many roads and disruption to travel was likely across the South Island. People were advised to proceed with care and keep up to date with the weather forecasts and travel advice.
MetService late tonight updated snow warnings for all the South Island's alpine passes and for Dunedin's Northern Motorway (State Highway 1), the Crown Range Road (linking Queenstown and Wanaka) and the Milford Road (SH94).
Lewis Pass (SH7)
From 5am to 10pm on Wednesday: A brief period of snow is expected to affect the road in the morning. Between 5am and 8am, 1cm to 3cm may settle above 700 metres. Then from 4pm to 10pm, a further 1 to 3cm could settle to low levels.
Arthur's Pass (SH73)
From 2am to 9pm on Wednesday: A brief period of snow is possible in the early hours of the morning, and between 2am and 7am, up to 3cm may settle on the road. Then from 4pm to 9pm, a further 2cm could settle.
Porters Pass (SH73)
From 2am to 9pm on Wednesday: A brief burst of heavy snow is possible in the early hours of the morning, and between 2am and 7am, 4cm to 8cm of snow may settle on the road. Then from 4pm to 9pm a further 2cm to 4cm could settle.
Haast Pass (SH6)
From 1pm to 5pm on Wednesday: Snow showers may briefly affect the road for a time during the afternoon, and 1 or 2 cm of snow may settle on the road above 400 metres, with lesser amounts down to low levels.
Lindis Pass (SH8)
Snow is forecast to affect the road for a time on Tuesday night. Between 9pm and 1am on Wednesday up to 4cm of snow could settle above 700 metres, and lesser amounts down to 400 metres. Then from 2pm to 9pm on Wednesday, a further 1cm to 3 cm could settle to low levels.
Dunedin Northern Motorway
Snow showers were likely to affect the state highway from midday on Wednesday until 4am on Thursday. Between 4cm and 8cm of snow was likely to settle on the road down to sea level.
Crown Range Road
From 8pm Tuesday until 12am on Thursday: Snow is forecast to affect the road for a time on Tuesday evening and overnight, with 2cm to 4cm possibly settling on the road above 600 metres, and lesser amounts down to lower levels. During Wednesday, a further 2cm to 5cm of snow could settle between midday and midnight, mainly above 500 metres, but lesser amounts were likely down to the valley floor.
Milford Road
From 8pm on Tuesday until 3am on Thursday: Snow may affect higher parts of the road for a time. From 8pm until 11pm on Tuesday, up to 3cm of snow may settle on the road above 700 metres. Then from 9am to 3pm Wednesday, snow showers were expected to low levels, and 3cm to 6 cm could settle above 500 metres, with lesser amounts to lower levels. From 3pm on Wednesday until 3am Thursday, 2cm of snow may settle on the road to low levels south of Lake Gunn.
'Bitterly cold' temperatures this week
MetService meteorologist John Law said temperatures will drop across the country.
"We are all going to feel this very cold air when it arrives mid-week.
"While temperatures in the central parts of the South Island will be the coldest, even up in the winterless north we could find temperatures cold enough for a touch of ground frost."
He said day-time temperatures will struggle to break double digits for many parts of the country on Thursday, in particular, with strong south-westerly winds whipping around coastal parts of New Zealand.
"The windchill is going to make it feel colder still."
- additional reporting ODT Online
