Weather: Snow, rain, wind set to pummel New Zealand as cold change moves in

Weather warnings and watches are in place for parts of New Zealand ahead of a cold change expected to bring snow, rain and strong winds.

Forecaster WeatherWatch said a "deepening area of low pressure and a growing high" were working in conjunction, causing a very wind and cold change ahead of the weekend.

"Thursday will be warmer than average before it arrives - then Friday becomes colder than average, at least in the South Island," WeatherWatch said in a statement.

"Another burst of heavy rain/showers moves in overnight [Friday] bringing further thunderstorms for the West Coast, this time with a risk of hail, these heavy showers then move into the lower North Island from Friday afternoon.

"While not a high risk there could even be a rumble with some small hail up the east coast of the South Island during Friday too, if not any thunder it will definitely become wet and cold in any case. 

"Winds will peak later on Friday and into Saturday for many parts of New Zealand."

Below are all the weather warnings and watches MetService currently has in place.

Northland

A heavy rain watch is currently in place in Northland until at least 7pm on Thursday.

MetService said periods of heavy downpours were possible in the region during this time. 

Bay of Plenty

A heavy rain warning is in place for the Bay of Plenty ranges east of Ōpōtiki from 7am until 10pm on Thursday, with MetService forecasting between 70 and 100mm of rain during that period. 

Wairarapa, Wellington and Marlborough Sounds

A strong wind watch is in place for these regions from 9am until 4pm on Thursday.

MetService said these areas could be exposed to severe gale-force winds.

The forecaster warned there was also a chance of severe gales in the Tasman District west of Motueka, Auckland, Coromandel, northern Manawatu, Tararua District, Hawke's Bay and Bay of Plenty.

Buller and Westland

A heavy rain watch is in place for Westland north of Otira and the Buller District from 5am until 7pm on Thursday.

MetService said a heavy rain warning was also in place for Westland north of Otira, with downpours expected in the area between 11pm on Wednesday and 3pm on Thursday. 

Canterbury 

A heavy rain watch is in place for the headwaters of the Canterbury lakes and rivers from 4am until at least 1pm on Thursday. 

According to MetService, a strong wind watch was also in place in the Canterbury High Country - with possible northwest gales between 11pm on Wednesday and 1pm on Thursday.

First snowfall of the year expected

Road snowfall warnings are in place for the lower South Island's Milford (State Highway 94) and Crown Range Rds.

MetService said snow showers were expected to impact the roads from late on Thursday evening.

"Cold air is forecast to move onto the South Island from Thursday night, with snow possibly falling as low as 400 to 500 metres across Southland and southern parts of Otago during Friday and Saturday," MetService said in its severe weather outlook

"Snowfall is not expected to meet warning criteria at this stage but could affect higher roads and bring stress to livestock across parts of the South Island." 

MetService said a heavy rain warning was also in place for Fiordland from 5pm on Wednesday until 6am on Thursday, while a strong wind watch was in place for central Otago, Clutha, Southland and Stewart Island from 9pm on Wednesday until 7am on Thursday.