Snow has started falling in Canterbury, Otago and Southland and is not set to let up until 6pm tomorrow.
The risk for the lowest level of snow occurs on Tuesday as cool air pushes in from the southeast, MetService says.
“Numerous roads are covered by road snowfall warnings and we’re forecasting up to 50cm for Porters Pass from midday Tuesday to 11am Wednesday,” Ferris said.
He said the weather system will linger through the week, but high pressure will build from the south on Wednesday and spread onto the North Island by the weekend.
“This high pressure will bring clear skies and light winds to the far south, which will mean morning temperatures deeply into the negatives,” Ferris said.
Meteorologist Mmathapelo Makgabutlane said it would be a wet day for Auckland today through to the evening.
“There may be a period of heavier rain tonight as a front moves across the upper North Island. The front looks to be moving fairly quickly, however, which means the heaviest rain is expected to only last a short while,” Makgabutlane said.
The snow that has started falling in parts of the South Island is expected to last up to three days.
Makgabutlane said the southeastern South Island, which is under the orange heavy rain warning, is an area to watch as “it is not often that we get such persistent rain in that area”.
“Snow is also expected for inland places, some of which could be heavy at higher elevations and could affect farmers and road users,” Makgabutlane said.
“Road conditions on high-level roads and mountains could be affected by snowfall as well.”
MetService said snow had started atop the Crown Range Road and is expected today and tomorrow across much of the South Island, reaching as low as 200m in Otago.
It warned of heavy snowfall on elevated areas in Southland, Otago and Canterbury.
The incoming system is set to deliver widespread wind and rain this week – and a potential heavy dump of snow in the south – with a raft of severe weather warnings in place.
The persistent and cold easterlies over the southern South Island is a result of a low over the Tasman Sea.
It is forecast to bring heavy rain and snow above 300m and southeasterly gales are expected to develop over western parts of the South Island late today through to tomorrow.
People are advised to keep up to date with the latest forecasts.
MetService forecaster Gerard Bellam said a large low-pressure system sweeping down from the Tasman Sea would be feeding moisture into a cold southeasterly flow, meaning wet, wintry weather for many parts of the south.
Areas northwest of Motueka could be soaked with up to 100mm of rain within a 12-hour period from 10am today.
Orange warnings have also been issued for North Otago, Dunedin and Clutha southeast of Raes Junction, with the potential for up to 120mm between noon today and tomorrow evening.
A snow watch was in place for South Canterbury, including the foothills and inland areas of Otago and Southland, as well as eastern Fiordland from today until tomorrow.
There was a moderate chance of that watch being upgraded to a warning, with snowfall possibly reaching warning criteria for the Otago, Southland, and Fiordland areas.
It is set to start falling at 9am and not let up until 6pm tomorrow.
The snow level was expected to lower to 300m to 500m overnight Monday and during Tuesday morning, with potentially large accumulations about eastern Otago.
Motorists using the Lindis Pass (State Highway 8), Milford Road (SH94) and Crown Range Rd – where as much as 15cm of snow was possible in places above 700m – were also urged to take care.
A heavy rain watch is in place for Mt Taranaki, Westland District, Southland and Clutha about and northwest of Raes Junction today. There was a moderate chance of these being upgraded to a warning.
Elsewhere, the weather system brought a risk of strong winds to areas including Westland and the fiords – and a heavy rain watch is in place for Mt Taranaki, Westland District, Southland and Clutha.
People in most parts of New Zealand could generally expect wet weather over the next few days, Bellam said – but in northern centres like Whanganui, which is forecast to hit a mild 17C today, conditions wouldn’t be as cold as in the south.
“As we head into Wednesday, we’ve got low confidence of heavy rain for eastern parts of the South Island – and on Thursday, we see that cold air in the south spreading up into the North Island,” he said.
“Once we get into Friday, we’ve got minimal risk of severe weather – but the early part of the week is going to be notable.
“I suppose that’s a mixed blessing, as we’ve had a fairly poor ski season so far and those South Island skifields have been anticipating water for snow.
“But people do need to take care and keep up to date with our forecasts and warnings for the next few days.”
