MetService has issued orange warnings for heavy snow in Canterbury, severe gales in Wellington, Wairarapa and southern Hawke’s Bay, and heavy rain in the Tararua Range as a fast-moving cold front crosses New Zealand on Sunday. It arrives on the first morning of daylight saving and in the first weekend of the school holidays.
The warnings were issued on Saturday morning and upgrade several of the watches MetService put out on Friday. RNZ reported that the front would move north quickly on Sunday, bringing short bursts of heavy rain, snow and gales to central parts of the country before clearing.
The heaviest snow is forecast for the Canterbury High Country and the plains near the foothills south of Arthur’s Pass. MetService expects 10 to 15 centimetres to settle above 400 metres between 5am and 11am Sunday, with lesser amounts down to about 200 metres. It warns of travel disruption, possible damage to trees and powerlines, and stress for livestock in the cold. That is a real concern for farmers in the middle of lambing and calving.
Gales are the other big threat. Wellington is under an orange strong wind warning from 6am to 11am Sunday, with severe northwest gales gusting to 120 km/h in exposed places. A second orange wind warning covers Wairarapa, the Tararua District and Hawke’s Bay south of Hastings from 7am to 3pm, with west to northwest gusts also reaching 120 km/h before winds ease from the south in the afternoon. MetService says driving may be difficult, especially for high-sided vehicles and motorcycles.
In the Tararua Range, 60 to 90 millimetres of rain is expected between 4am and 2pm, with peak rates of 15 to 20 millimetres an hour on Sunday morning. MetService warns streams and rivers may rise rapidly and that surface flooding and slips are possible. That upgrade is notable. On Friday, MetService meteorologist Heather Keats told 1News the rain would be brief and “unlikely to meet the thresholds for any watches or warnings”. By Saturday morning the Tararua Range had an orange warning.
Lower-level yellow watches are in place for heavy rain and possible thunderstorms in Buller, heavy snow above 400 metres in Central Otago and the Queenstown Lakes District, and northwest winds that may approach severe gale in Horowhenua, the Kāpiti Coast and the Marlborough Sounds. MetService rates the chance of those watches becoming warnings as moderate.
Road snowfall warnings cover most of the main South Island alpine routes. Porters Pass on State Highway 73 could get 10 to 15 centimetres about the summit between 7am and noon. Lindis Pass on State Highway 8 could get 3 to 8 centimetres from 3am to 9am, and Lewis Pass on State Highway 7 could get 3 to 6 centimetres from 10am to 5pm. Arthur’s Pass may get 2 to 5 centimetres between 8am and 1pm, while the Crown Range Road and Haast Pass could each get 2 to 6 centimetres early on Sunday morning. On the Milford Road, MetService expects 2 to 4 centimetres above 400 metres before dawn. Rain may briefly turn to snow on the Dunedin to Waitati Highway, but little, if any, is expected to settle.
Anyone driving on Sunday should check the NZ Transport Agency’s journey planner before setting out, particularly over the alpine passes and exposed stretches around Wellington and the Wairarapa.
Keats said the front would be “very active” and “fast-moving”, with the wind “the standout feature”. She said the strong winds would stretch “all the way from Cape Reinga down Northland, Auckland, Coromandel, Hawke’s Bay, Wairarapa, the central North Island, Marlborough Sounds, Kaikōura, all the way down to Dunedin, Clutha and the Chatham Islands.”
“But if you’re travelling, it could be problematic. So it’s definitely going to be a day to plan if you’re travelling for school holidays,” she said.
Her colleague Lewis Ferris had given a similar warning on Thursday. “It’s going to be brief, but heavy,” he told 1News. “You wouldn’t want to be out riding a motorcycle or driving a campervan, just with the potential for the big gusts on Sunday.”
Hawke’s Bay faces some of the biggest temperature swings. Keats said the region would reach 23C on Sunday afternoon, ahead of the front. “But cruelly, Sunday night they’ll drop down to 3C. So that’s a 20C difference,” she said.
The timing adds to the disruption. Daylight saving starts at 2am on Sunday 27 September, when clocks go forward an hour. The early warnings for snow and wind begin between 3am and 7am, so people setting off early for the holidays will lose an hour of sleep and meet the worst of the weather at the same time. MetService’s warning times are given in daylight saving time.
The front follows a week of sharp swings. Earlier in the week a burst of southern air sent much of the North Island below zero just after the spring equinox, and Keats said it fell to minus 5C at Matea in the central North Island early on Friday.
Ferris said the unsettled weather would be short-lived, with high pressure in the Tasman Sea settling things from Monday. He said Monday to Wednesday looked largely fine, although showers could linger in the south and west of the South Island and another frosty morning was possible on Monday. He said late-season cold snaps were not unusual. “We’re just kind of getting into that time of year where maybe you don’t expect them so much,” he said.
MetService says the chance of any of Sunday’s orange warnings being upgraded to red is minimal. Even so, fast fronts can be hard to time, and warnings are often adjusted overnight. It is worth checking again before heading out on Sunday morning.
Are you travelling this weekend, or waking up to snow or gales on Sunday? Tell us how it looks where you are in the comments below.
This article was written by AI, briefed to report the facts, hopefully without some of the bias people bring to the job 🙂
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