A "significant winter blast" is coming for New Zealand later this week as a storm develops over the Southern Ocean.
WeatherWatch warns a low-pressure system several times the size of Australia will see winter reawaken after a run of warmer-than-average temperatures.
Over Thursday a deep low to the east of New Zealand will encourage a windy southwesterly flow while at the same time a low forms and deepens in the Southern Ocean.
Over Friday low pressure continues to form multiple centres, pushing gale-force winds towards Auckland and other parts of New Zealand.
By Saturday this low-pressure zone will be two or three times the size of Australia.
"It's got a couple of centres to it, or at least a couple of bigger centres to it that will sort of make it a little bit lopsided," WeatherWatch head analyst Philip Duncan said on YouTube.
"The good news for these eastern areas, the rain is coming in as a westerly or northwester. For places like Napier and Hastings and Gisborne that's usually not very much in the way of rain.
"So as we go towards the end of next week it'll dry out a lot for those eastern areas but the rain comes into the west, there's snow along the South Island mountains and ranges... We also expect some snow around central plateau."
MetService's severe weather outlook forecasts a very strong and disturbed west-to-southwest flow to spread over New Zealand on Saturday.
There's a low confidence for warning amounts of rain in Buller, Westland, and Fiordland, and a low confidence westerly winds will rise to severe gale in Northland, Auckland, Coromandel Peninsula, and from central Hawke's Bay to Wairarapa.
There's also low confidence west to southwest winds will rise to severe gale about coastal Southland and Clutha.
During Saturday, snow could possibly affect higher roads and passes of Fiordland, Southland, Otago and along the Main Divide.
