Blast of strong winds, hail, snow to strike New Zealand

Kiwis should brace themselves for a tumultuous, cold end to the week, with damaging gusts of wind, thunderstorms, hail and low-terrain snow possible.

Temperatures dropped harshly overnight in the South Island and the whirlwind of cold weather will hit the North Island later on Wednesday.

Newshub's Kaysha Browlie told The AM Show that it was a wake-up call for locals after a fairly warm winter so far.

"Temperatures plummeted overnight here in Tekapo and we have woken up to a blanket of snow," she said.

"We are two-thirds of the way through winter already and it has been pretty warm. Locals could be forgiven for thinking they were going to get through without this cold snap. 

"But today, on the final day of July, mother nature has reminded us we still have a whole month to get through."

Motorists are being warned to put chains on their vehicles and keep an eye out for updates on Alpine passes.

"It's not the day to go out sightseeing," Browlie said.

But that winter wallop isn't the only blast of cold Kiwis are likely to see this week.

NIWA forecaster Chris Brandolino told The AM Show that a "weather crescendo" is beginning.

"I see this evolving as a sort of weather crescendo, we start off, if you know music, you start of kinda start soft and light and then as you go through time it grows and grows and grows and grows," Brandolino said.

On Wednesday, he says there will be some cold rain for commuters in Christchurch and possible thunderstorms and hail in the North Island. 

"[In the South Island], we are going to get snow over higher terrain, roughly above 300m, a cold rain for Christchurch, so that will greet the morning commuters and that will be lifting north throughout the day.

"For the rest of the North Island, I think it is this afternoon, and especially later this afternoon and tonight after sunset, where we get some showers, some thunderstorms and maybe even some hail as the cold air moves through."

While Thursday will be more of a cool typical winter's day, Friday is where the tumultuous weather takes a step up.

"It's Friday that we get a second round, that crescendo takes another step up. More wind, more rain, especially later in the day.

"We have got to watch the wind. Friday night into Saturday for the North Island could be some damaging wind gusts there."

The blast will then reach its peak in the weekend, according to Brandolino, with more cool gusts and possible low terrain snow on Sunday in Dunedin and Invercargill.

There are also king tides expected and Brandolino warns that livestock could see hypothermia due to the cold wind over successive days.

Newshub.