Weather forecast: Snow and wintry weather to grip NZ for the weekend

Snow, gale-force winds, frosts, lashing rain and freezing temperatures are going to give this spring weekend a wintry blast.

Snow levels are predicted to drop to 200m in the west of the South Island tomorrow as temperatures plunge, MetService meteorologist Michael Martens said.

A heavy snow warning for Fiordland could disrupt travel in affected areas, distress livestock, damage trees and powerlines. Up to 35cm of snow could fall above 400m, and lesser amounts down to 200m. The heaviest snow is expected to fall on Saturday morning, when 10 to 15cm may accumulate in six hours.

Snow in the western ranges again tomorrow as a cold front moves up the South Island. Check https://t.co/nhvDAxG4ZR before you travel. ^TA pic.twitter.com/h8TfrZVI3A

— MetService (@MetService) September 7, 2017

Parts of the North Island will also see snow to 700m on Sunday, which could affect Desert Rd.

An unsettled springtime northwesterly flow will change to a southwesterly direction on Saturday.

"It'll be very showery, maybe thunderstorms with hail. Most of the people in the country will see that," Martens said.

"It looks like a late wintry weekend for most of the country. It's going to be pretty miserable for most people."

A heavy rain watch is out for Westland and Fiordland today, along with a strong wind watch for Hawke's Bay, the Tararua District, Wairarapa and the Canterbury High Country.

Westerlies keep on coming 7/9/17

Strong westerlies to stick around Strong westerlies are a staple part of spring weather, and are set to stick around for a while. This clip shows one model's take on the weather out for the next few days, and you will notice those westerlies just keep on coming. On Sunday they turn more southwest, meaning temperatures will take a dive, followed by a very brief pause early next week. You can also see that while most of the rain is in the west, it does make its way across the ranges from time to time. Find full day to day forecasts for your town on http://bit.ly/metservicenz ^TA

Posted by MetService New Zealand on Wednesday, September 6, 2017

Winds were expected to hit more than 90km/h in western parts of the country.

The South Island wouldn't see a high in double digits as the wind changes to a southerly direction on Saturday. Frosts would be widespread in the South Island, Martens said.

"Even Auckland could see temperatures struggling to reach 12C as that cold air spreads north as well."

Wellington would be one of the best places to be this weekend as it is relatively sheltered from westerly weather by the mountains. But even a little direction change could see showers slip through, Martens said.