A small tornado and high winds north of Wellington have torn rooves off buildings, blown cars off roads and injured several people.

The twister hit 1.5km north of Waikanae on the Kapiti Coast about 4pm, police central communications Inspector Paul Jermy said.

Several people were believed to have been injured, including a woman who was taken to Wellington Hospital after an uprooted tree crushed the caravan she was in.

Another person had to be rescued from their home after a tree fell on it, trapping them inside.

Mr Jermy said a man suffered minor injuries to one hand after the tornado toppled a van on State Highway 1.

It also lifted a roof or shed of a nearby property and blew debris onto the road, he said.

Fire Service central communications shift manager Murray Dunbar said firefighters had been called to 30 weather-related incidents in Kapiti, Wellington and Wairarapa since midday.

Most of the callouts involved fallen trees, smashed windows and flooding, he said.

Firefighter John Arthur said he saw a large amount of damage.

“There was one car on its side lying in a ditch and there were three other cars which had a fair bit of damage,” he told Radio New Zealand.

“The big, historic woolshed was quite badly damaged and I could see another building, possibly a shed, had been demolished.”

Thunderstorms, heavy rain and strong winds today lashed much of the country from Waitomo to the west coast of the South Island.

Marble sized hail was falling and there was reports of drifts of hail on some roads, including the Rimutaka Hill Rd, between Wellington and Wairarapa, the MetService said.

Drivers needed to be careful, especially after dark.

Winds were gusting up to 120km/h and large waves were lashing the western coast of both islands for the next few days.

The cold snap brought a large dumping of snow to Treble Cone Skifield at Wanaka bringing instability and a high risk of avalanche to some areas.

As of this afternoon it had 65cm of snow at the carpark.

The amount of snow directly onto wet tussock had created the avalanche risk an instability workers had not seen in their ten years at the skifield, the skifield said on its website.

The skifield would open the leaners slope and other operations at the base tomorrow, but there would be no access above the base area.

The weather was caused by westerlies from the Tasman, which had active troughs that “strengthened the winds and pushed thunderstorms across the country”, Metservice forecaster Geoff Sanders told NZPA.

Heavy rain was soaking the west coast of the South Island.

Severe gales were also battering parts of the South Island from Marlborough to Southland and parts of the central and lower North Island.

“The North Island is in line for some quite heavy showers in most places, today and tomorrow,” Mr Sanders said.

Another front bringing wind was expected to cross the South Island tomorrow.

It had already been cold there with quite a bit of snowfall, Mr Sanders said.

A significant amount of snow was also expected over the South Island mountains and snow could also fall to low levels in Canterbury, Otago and Southland.

There was also a possibility for significant snowfall as low as 400m around the MacKenzie Basin and south Canterbury overnight.

The MetService would continue to monitor the situation closely. Mr Sanders advised people to keep an eye on weather updates.

Civil Defence said as storms approached people should:

– Take shelter indoors away from windows.

– If outside, avoid sheltering under trees.

– Move cars under cover or away from trees.

– Secure any loose objects around properties.

– Check drains and gutters are clear.

– Be ready to slow down or stop, if driving.

People also needed to beware of fallen trees and power lines and avoid streams and drains as flash flooding could sweep people sway, Civil Defence said.

– NZPA