Severe weather warning: Rain, wind, snow forecast as subantarctic system moves in

Gale-force winds and torrential rain are striking the country today, with more downpours expected around Gisborne, gusts in Wellington, snow on the Central Plateau and a sudden turn tipped for Auckland during rush hour.

MetService has issued a raft of severe weather advisories, including a strong wind warning for the Wellington region from noon to 7pm tomorrow.

The forecaster said gale-force northerly winds could gust at 120km/h in exposed parts of the region, with NZ Transport Agency Waka Kotahi also urging motorists travelling in the area to take extra care.

Severe gales were also possible throughout Monday afternoon in South Taranaki, Taihape, inland Whanganui, southern Wairarapa, and inland and northern parts of Marlborough.

Further south, MetService has issued orange heavy rain warnings across Fiordland, the headwaters of the Canterbury and Otago lakes and rivers, and the ranges in Westland – and road snowfall warnings for elevated parts of Milford Rd, Lindis Pass and Crown Range Rd.

A heavy snow watch was issued for Central Otago northwest of Alexandra, including the Queenstown Lakes and the MacKenzie Basin. The Desert Rd on State Highway 1, meanwhile, had a road snowfall warning from 1pm to 7pm Tuesday, with a centimetre of snow slated to settle.

The wintry conditions came as a cold front moved in from the west on Monday, with an area of low pressure crossing the South Island.

“By Tuesday and Wednesday all of New Zealand will be colder – and despite some minor fluctuations, the colder subantarctic air may linger into next week for many places too,” WeatherWatch reported.

While the chilliest weather would hit in the south and east of both islands – directly in the path of the mass as it moved off the Southern Ocean – the website expected to see colder air spread right across the country throughout the week.

Overnight temperatures were forecast to fall as low as 4C in Auckland on Wednesday – and 0C in Hamilton.

WeatherWatch said snow flurries were also likely about Ohakune, Waiōuru and the Desert Rd on Tuesday.

In the South Island, snow was possible on the hilltops around Dunedin and close to the main centres of Southland and Otago.

“Out of all the main centres, Queenstown is most likely to get some snow, with that main chance on Tuesday.”

Over the rest of winter and beyond, however, Niwa’s just-issued three-month outlook has picked near or above average conditions in all regions – with fewer winter cold snaps and frosts than normal.

As well, it warned of the potential for another big downpour in mid-July, courtesy of a pulse of subtropical moisture called the Madden-Julian Oscillation, which also had a hand in last week’s storm.

Niwa further predicted a 60% to 70% chance of a La Nina climate pattern returning by spring – bringing its characteristic warm and moist influence to New Zealand’s northeast.

Jamie Morton is a specialist in science and environmental reporting. He joined the Herald in 2011 and writes about everything from conservation and climate change to natural hazards and new technology.