More wet and wild weather is set to hammer swathes of the country this week, with heavy rain, severe gales, snow and a frosty chill on the cards over the coming days.
The wintery conditions are forecast to blast stretches of the South Island, which has been issued with a slew of severe weather warnings on Monday.
"It's the next instalment in the show we call 'winter' and it's coming to a place near you over the next two days," a WeatherWatch meteorologist said on Monday. "This is normal August weather but it does [pose] a number of severe weather risks across the country."
A large low drifting up from the south will brush Aoetearoa from Monday to Wednesday, impacting various parts of the country.
"It's not as intense as the weather last Monday but does bring severe weather risks into both main islands, especially on Tuesday. The low isn't really a storm - but does press into higher pressure north of New Zealand, helping to create windier weather," WeatherWatch explains.
It's a particularly wet start to the week for the West Coast, with MetService warning of surface flooding, slips and hazardous driving conditions in the Westland District, in and south of Otira.
Around 190 to 220mm of rain is expected around the ranges from Monday afternoon, with 100 to 130mm near the coastline.
"Heavy rain may be accompanied by thunderstorms," MetService says. "Heavy rain may cause streams and rivers to rise rapidly. Surface flooding and slips are also possible and driving conditions may be hazardous."
Rainfall in Westland north of Otira is also being monitored, with periods of heavy downpour and possible thunderstorms expected to strike from Monday afternoon.
The Buller District and Nelson west of Motueka, as well as the Nelson Lakes National Park, is also under siege from the storm, with a heavy rain warning remaining in place from Monday evening until the early hours of Wednesday morning.
Torrential rain and thunderstorms are forecast to batter the Fiordland region from Monday morning through until Tuesday, while heavy rain warnings have also been issued for the headwaters of lakes and rivers in the Canterbury and Otago regions, with the downpour expected to cause bodies of water to rise rapidly.
"Surface flooding and slips are also possible and driving conditions may be hazardous."
But the North Island is not spared from the deluge, with heavier falls also expected as far north as Mt Taranaki to the west and Mt Ruapehu in the Central Plateau.
"This is a West Coast rain event for the most part with some heavier falls as far north as Mt Taranaki/Mt Ruapehu in the North Island. But rainfall totals diminish the further north you go on the western side and increase as you head south towards (and into) Fiordland. Showers will be more likely elsewhere with lower accumulation," says WeatherWatch.
A heavy rain warning is in place for the Tararua Ranges, with additional rainfall possible overnight on Tuesday and into Wednesday. Downpour may also approach warning criteria in the Bay of Plenty ranges, east of Whakatane, as well as Taranaki around and north of the mountain, Taumarunui and Taihape, including Tongariro National Park.
Meanwhile, sheets of snow are expected in the usual places, such as the Southern Alps and the South Island ranges. Mt Taranaki and the Central North Island volcanoes are also in for some significant snowfall over the coming days, while a few flurries may flirt with lower areas in northern Southland.
"It's mostly just a cold pulse of air moving through. Both Tuesday and again on Friday will be the coldest days of the week in the lower part of the South Island," WeatherWatch says.
Road snowfall warnings are currently in place for Lewis Pass (State Highway 7), Arthur's Pass (State Highway 73), Haast Pass (State Highway 6), Lindis Pass (State Highway 8), Crown Range Rd, and Milford Rd (State Highway 94).
Windchill will be tough for newborn lambs in particular later on Tuesday and into Wednesday, before easing towards the latter half of the week.
"Milder west to north-west winds precede the cold front - which moves into the lower South Island on Tuesday and more nationwide by Wednesday," WeatherWatch says.
"It's not a major cold event for northern New Zealand, but [we'll] see a cooler week ahead. In fact, this week is average to below average temperature-wise nationwide - the first time in some time that has happened."
Those west to north-west winds will continue to build on Monday, rising to severe gales overnight and into Tuesday in exposed areas, such as the Cook Strait and lower North Island.
"The most exposed [areas] look to be through the Southern Alps and about Central New Zealand, with Wellington and the Marlborough Sounds most exposed on Tuesday morning to north-west severe gales."
Strong wind warnings have been issued across the South Island, from Wairarapa, Wellington and Marlborough, through to Canterbury High Country - north and south of the Rakaia River - and Otago and Southland, including Stewart Island.
North to north-west winds may approach severe gale in exposed places across the Buller District, Westland north of Hokitika and Nelson west of Motueka, as well as the Canterbury Plains, including Christchurch, and Fiordland.
