Another spring blast is about to hit New Zealand this week with severe gales expected for parts of the North Island, including Auckland City.
"The first set of potentially damaging winds will be over the next day in the lower North Island - mainly Wellington and southern coastal Wairarapa and the southern entrance to Cook Strait. This is due to a nearby low-pressure zone," WeatherWatch said on Tuesday.
A NIWA graphic showed a "polar jet stream" pattern driving a Southern Ocean cold front up New Zealand.
Road snowfall warnings were already in place for Lewis and Porters Passes (State Highway 73), Lewis Pass (SH7) and the Desert Rd until at least Wednesday morning.
But NIWA said the new cold front could cause more low-elevation snow, cold temperatures, strong winds and big waves come Saturday.
From Friday, a low-pressure system in the Southern Ocean was expected to combine with a high-pressure zone in the southeastern corner of Australia, causing powerful westerly winds to sweep across the South Island and into the North Island - meaning Aucklanders could expect winds over 100km/h on Saturday, WeatherWatch said.
"By Saturday those winds spread as far north as Auckland City with gusts over 100km/h possible. In true spring style, it all blows through fast though."
MetService already has multiple severe weather warnings in place.
"An active trough embedded in this [southwest] flow is expected to affect the country on Friday and Saturday, then the flow turns northwest over southern New Zealand on Sunday ahead of another trough over the Tasman Sea," it said in its severe weather outlook.
"There is moderate confidence of severe westerly gales for the Tararua District and Hawke's Bay south of Cape Kidnappers on Friday plus Saturday morning, and low confidence of severe westerly gales returning on Sunday.
"On Saturday, there is moderate confidence of severe west to southwest gales for Northland, Great Barrier Island, Auckland, Waikato, Coromandel Peninsula and western Bay of Plenty.
"There is also moderate confidence of severe southwest gales for Mahia Peninsula and near the coast of Tairawhiti/Gisborne."
