Gusts of up to 130km, more than 3000 lightning strikes, and the cold is set to bite

METSERVICE/TWITTER

The South Island is set to shiver as a front brings rain, and potentially snow to low levels.

High winds knocked power out and disrupted events in the lower North Island overnight, while lightning strikes have given way to snow warnings in the south as wintry weather moves up the country.

MetService issued a heavy rain warning for Fiordland, Westland south of Otira, and the headwaters of Otago and Canterbury Lakes and Rivers, as heavy downfalls are expected on Tuesday. 

In addition, northwesterly winds could reach severe gale strength in exposed parts of Canterbury High Country, Marlborough and Wellington -  MetService said a strong wind warning is in force.

Earlier gales in the lower North Island had caused trees to be blown over and blackouts to about 650 properties in Wairarapa, while winds of up to 133 kilometres an hour in Wellington had led to at least one Days Bay ferry sailing being cancelled and an early closure for the Lux festival in the city on Sunday night. 

A tree fell across SH2 hitting a car south of Greytown, but there were no injuries.

It was beginning to feel a lot like winter in the deep south, with snow possible down to 300 metres in Otago and Southland, and Invercargill not expected to get above 8 degrees Celsius on Monday.

At 10pm Sunday, MetService tweeted there had been almost 3500 lightning strikes during the day, most on the West Coast, with the Southern Alps blocking thunderstorms from getting too far east.

After that the thunderstorm activity moved to the lower North Island, with around 700 lightning strikes counted in the four hours to 5am Monday, mostly in northern Wellington, Kāpiti Coast and Taranaki, MetService meteorologist Stephen Glassey said.

Thunderstorms moved north overnight to the lower North Island, but much of the country looks like having a window of fairly settled weather on Monday. (File photo)

Two Air New Zealand flights bound for Queenstown were diverted on Sunday when they were struck by lightning.

'UNSETTLED PERIOD'

Despite that, Monday was shaping up to be something of a rest between bouts of rough weather, with much of the country expected to be dry for much of the day.

"We have a front that is weakening as it moves north over the North Island, but it has been quite active during the overnight period," Glassey said.

"That front is weakening as it moves north. We're expecting the shower activity to die off a little bit today.

"Then tomorrow there's another active trough that's going to move onto the country bringing more showers and rain, specially in western areas," Glassey said.

"It's actually quite an unsettled period, from the last few days and also for the next week. There's a number of troughs moving over the country.

"We have low pressure systems passing to the south of New Zealand and a number of troughs embedded in a westerly flow moving over the country. It's a very unsettled period of weather, specially for western parts of the country," he said.

"It's gradually bringing colder air. With the trough today, the coldest air moved onto the lower South Island, but with the trough tomorrow the cold air makes its way further north onto parts of the North Island.

"We're forecasting snow to 300m in Southland this morning. I haven't had any reports to verify that,but it's certainly quite cold down there."

MetService has warned of a risk of snow on Lewis Pass, Arthur's Pass, Lindis Pass, the Crown Range Road and Milford Road.

Early Monday the NZ Transport Agency was reporting State Highway 94 from Milford to Te Anau was closed by snow at Hollyford Rd.

Auckland is forecast to have just occasional showers on Monday with a 19C high. Wellington looks set for a fine day with a 16C maximum and northerlies that could be strong at times. Christchurch is expected to be mainly fine with a high of 13C. 

On Tuesday, heavy rain is expected in the west of the South Island, falling as snow to 800m at times, or possibly even lower in the deep south. Severe gales are forecast for the east of the South Island on Tuesday, and for Wellington and Wairarapa.