"The snow's already gone over the South Island," Masters said.
"By the time it reaches the North Island it will lift most of its energy. We'll get a subtle change through Wellington, maybe a few showers.
"It's moving quite quickly. It'll be gone by tomorrow morning. It'll be moving into the Pacific by tomorrow morning and by then we'll be into a cooler southwesterly flow.
"Those poor people down South, they'll be in the freezer, minus five. That is really severe. However the ground temperature might be minus 10."
To confirm last 3 hours accumulation at base
Posted by Coronet Peak on Friday, 5 June 2020
Aucklanders will be handed a merely "coolish" high of 15C for the next five days, it will be relatively frosty in the central North Island over the coming week, dipping into the low single digits.
Lack of cloud cover will keep the North Island cool, Masters said.
"So all the warm air escapes into the atmosphere. We can see some frosty temperatures over the next couple of days for those central parts of the North Island."
The MetService has issued snowfall warnings for seven major roads and highways. The Lindis Pass (SH8) between Omarama and Tarras has been closed because of snow and ice, and snowfall warnings are in place for Lewis Pass, Arthurs Pass, Porters Pass, Haast Pass, the Crown Range Rd and Milford Rd.
South Island skifields have also been reporting welcome snowfall today as the season opening nears. Coronet Peak near Queenstown posted a photo to social media showing 23cm had fallen over a three-hour period this morning.
"As [the change] pushes up through Canterbury, we're expecting snow this evening down to between 400-500m and between 600-700m around the Kaikoura coast," MetService meteorologist Andy Best said this morning.
Most of the nasty weather will pass through Auckland overnight.
"We have a few showers but they do become widespread over Auckland tonight with the southwesterlies pushing through," Best said.
"Sunday morning, those showers are expected to clear before dawn, leaving the southwesterlies and cloudy periods.
"Auckland tomorrow isn't too bad at all. Temperatures are around about average for this time of year, 15C is the maximum expected."
Sunday forecast
Whangārei: Cloudy periods. Showers clearing before dawn. Southwesterlies. High 15C, Low 8C.
Auckland: Cloudy periods. Showers clearing before dawn. Southwesterlies. 15C, 10C.
Hamilton: Cloudy periods. Showers clearing before dawn. Southwest breezes. 14C, 4C.
Tauranga: Fine. A few showers clearing before dawn. Southwesterlies. 15C, 6C.
Wellington: A few showers clearing before dawn. Becoming fine as southerly breezes turn northerly in the morning. 12C, 7C.
Christchurch: A frosty start then fine. Northwesterlies. 12C, 0C.
Dunedin: A frosty start then fine. Light winds. 12C, 5C.
Invercargill: Occasional showers. Fresh westerlies. 10C, 5C.