A locked-down New Zealand - including Auckland - is further battening down the hatches as a wet and windy storm batters the country.

Wild weather across the country has downed power lines, caused slips and flooding that has closed roads, and brought relief to the drought-stricken Northland region today.

The blustery front has been whipping up New Zealand all day, with high winds lashing Wellington, and earlier across Canterbury, where gusts hit 104km/h at Le Bons Bay on Banks Peninsula just before midday.

The strong gusts have lifted a roof in Taranaki and left roads scattered with debris.

It's also made for choppy waters in Akaroa Harbour, we all as Lake Tekapo and the Cook Strait, where the winds have been whistling through, MetService says.

A strong wind watch is in place for Auckland, with "strong to gale force" northeasterly winds expected throughout the afternoon and into evening. Gusts could potentially reach 100km/h in exposed places.

"The rain is bucketing down at the moment and has been falling steadily for at least an hour," a Herald reader in Auckland said.

"I can hear it thundering on the roof and dripping from my busted gutter. My garden's loving it but it's not so welcome for my 6 and 8-year-old, who have some serious lockdown cabin fever."

The rain will be welcome to Auckland's Watercare. Dams which supply the city's water were less than half full earlier this week, and water-saving measures are already underway including calls to limits showers to four minutes.

A heavy rain watch has been flagged for Northland where a drought was declared on February 11.

The region has seen periods of heavy rain today, with Opononi on the south shores of Hokianga harbour seeing 15mm of rain in just one hour between 11am and midday.

"We know Northland is obviously pretty dry and in need of some rain and hopefully this will bring some relief at least to those empty water tanks up there," said MetService meteorologist Tom Adams.

The West Coast has been lashed by rain - and now MetService says residents should brace for possible thunderstorms.

Heavy rain overnight closed State Highway 6 east of Westport this morning, between Inangahua and Westport, with slips at each end of the Lower Buller Gorge, at Uranium Point and at Inangahua. SH6 south of Westport to Greymouth is open, but rain is continuing to fall in northern Westland and Buller district.

As well as the Lower Buller Gorge slips, the road south of Inangahua was also closed this morning due to surface flooding between Inangahua and Reefton but has since reopened.

"We encourage people to avoid using the roads in these conditions and please be on the lookout for surface debris. Slow down if you do have to make a journey," said Waka Kotahi West Coast maintenance contract manager Moira Whinham.

SH67, north of Westport to Mohikinui, has also had some surface flooding but remains open.

Heavy rain watches and warnings are also set for the ranges of Westland, south of Otira, Taranaki, eastern Bay of Plenty hills, and Tongariro National Park and the Kaimanawa Range.

Some Wellingtonians woke up to the sound of rubbish being scattered across their streets.

A strong northerly wind has been howling through the capital all day coupled with lashings of rain.

Meanwhile, MetService has been posting photographs on social media this morning of dumps of snow at Australian ski fields.

And although the weather isn't always mirrored across the Tasman, the forecaster expects Canterbury and Otago high country areas to get decent snow dumps early this week.

While temperatures remain autumnal-mild today, they are set to plummet over the next 48 hours, thanks to a predicted southerly blast.

Snow is forecast to around 700m and MetService is warning that frosts are possible in some South Island spots.