A tornado that hit Christchurch has left two people injured, ripped roofs off buildings and scattered debris – some contaminated with asbestos – through the air.

The storm briefly cut power to more than a thousand homes throughout the city and left part of a tree upside down in powerlines.

It hit about the same time as hail rained down on the city on Monday afternoon.

JOSEPH JOHNSON/STUFF A tree branch on powerlines over traffic on Waltham Rd.

Two people were injured at the SaveMart secondhand shop on Battersea St in Sydenham when the tornado hit the roof. Emergency services were called there about 1.55pm.

READ MORE:

* Live updates - Christchurch storm

* 'Tornado confirmed', says MetService

* Asbestos risk from Sydenham debris

Did you see the tornado? Send your photos, videos or eyewitness accounts to newstips@stuff.co.nz

Supplied The formation of a tornado in Christchurch has been captured on camera.

ASBESTOS DANGER

The tornado ripped off parts of a DJ Auto roof, spewing asbestos-contaminated debris into the air and over Wordsworth St in Sydenham.

Firefighters wore masks for the clean-up, which was expected to take about an hour, as the debris was drying and crumbling on the street. Wordsworth St, between Waltham Rd and Gasson St, closed shortly after 3pm.

SUPPLIED The tornado rips a roof from a building in Christchurch.

Fire and Emergency New Zealand (FENZ) assistant area commander Mike Bowden warned people not to touch any debris or take it home as a memento.

Canterbury medical officer of health Dr Alistair Humphrey said the public health risk from asbestos in this case was minimal.

"There's always a concern when you've got asbestos blowing around, but I'm sure the fire service has the matter in hand and they will clean it up appropriately."

Inhaling or swallowing asbestos fibres can cause scarring of the lung, as well as types of cancer, according to the Ministry of Health website.

While there was no established safe limit, the ministry website said the risk from a single, low-level exposure was extremely low. The presence of asbestos-containing material was not a risk in itself, the ministry said. There was risk of health problems if the fibres became airborne.

STORM LEAVES TRAIL OF DAMAGE



"[We have] a swathe of damage through Christchurch from this very short and sharp burst of weather."

A tornado forms in Christchurch.

Damage was reported from Sydenham to New Brighton, he said.

The FENZ southern communications centre received about 25 weather-related callouts between 2pm and 3pm as the storm made its way across Christchurch, spokesman Andrew Norris said.

He said crews attended callouts for air conditioners, trees, powerlines and roofs being lifted by heavy winds throughout the city.

SUPPLIED/JARED RAINES A tree has landed upside down in powerlines during a storm in Christchurch.

The SaveMart and the DJ Auto Importers incidents were among the more serious incidents, he said.

LIGHTNING STRIKES START FIRES

Lightning strikes are thought to have started four small fires in trees in Leeston.

Supplied/Josh Sagar A timelapse of the Christchurch storm.

Another fire, about 200 metres in size, started in sand dunes at Waikuku beach.

SAVEMART WORKERS HEAR 'BIG BANG'

Staff at SaveMart told Stuff that an electrician was working up a ladder, near the ceiling of the building, when the tornado hit. He fell possibly several metres and was injured. A woman customer, who had a toddler with her, had something hit her head.

SUPPLIED At least one person is understood to be injured after a tornado hit Christchurch.

The staff said the hail sounded like someone "throwing bricks on the roof" and there was a "big bang" when the tornado hit, which they thought was a plane crash or an earthquake.

The tornado left a hole in the roof of the building, lifting a section up by about 30 centimetres, and water was falling into the store.

St John said the two had moderate injuries and were heading to Christchurch Hospital.

SUPPLIED/KERRY ANDREWS The storm hit Burnside, Christchurch, on Monday afternoon.

The boss of the electrician, who asked not to be named for privacy reasons, said the electrician became "concerned the roof was going down". He was taken to hospital to be checked but did not appear to be seriously injured.

He said on Monday evening the electrician was having X-rays taken but "was going to be alright".

THUNDERSTORM 'SPAWNED' TORNADO

BRAD SMITH / SUPPLIED A tornado over Christchurch on Monday.

MetService meteorologist Peter Little said the tornado ripped across the city from about 1.45pm to 2pm, accompanied by large hail stones and rain, he said.

"This was one particularly large thunderstorm, which moved over the city and spawned a tornado."

The front then moved offshore, where there were reports of water spouts on the ocean.

SUPPLIED/LYNDAL CLARK A view of the storm rolling in from Huntsbury Hill, Christchurch.

MetService meteorologist Lewis Ferris said the thundercloud was 12 kilometres tall, right up to the top of the troposphere, the lowest level of the atmosphere which contains all our weather.

A severe thunderstorm watch remained, but "the activity should be starting to die down now", Little said.

'DEBRIS WAS FLYING AROUND'

JOHN KIRK-ANDERSON/STUFF A woman battles sudden hail in Christchurch. A tornado hit Sydenham just south of the central city about the same time.

Builder Ben Nolan was working in Sydenham when he noticed a black sky in the distance then a minute later, saw sheets of iron and even half a tree "swirling in the air".

"Then the next thing you know the tornado comes around a million miles of knots and the roofs were coming off all the buildings.

"Pink batts, trees, bits of everything in the air. It was quite silent, then it stated getting noisier and noisier."

JOHN KIRK-ANDERSON/STUFF Hail hits Christchurch on Monday afternoon.

Nolan believed the tornado lasted about 10 minutes.

Brad Smith was inside when Nolan told him about the tornado and recorded it on his phone.

"The debris was flying around it was really silent, swirling around, 500 to 600 metres above us."

'THE WORST IS OVER'

Weather charts on Monday morning showed small tornados were possible in the east coast of the South Island.

Hailstorms began in the inland areas of south and inland Canterbury around 10.30am on Monday and by midday heavy hail hit Ashburton before travelling across the Canterbury plains and Christchurch, he said.

At 12.30pm, MetService issued a severe thunderstorm warning as a front moved from Ashburton towards urban Christchurch.

At 1.10pm, a house in Palmerston, Otago was reportedly struck by lightning, blowing fuses and and power plugs off the walls.

"The worst is over for most people," MetService meteorologist Andrew James said.

'TAKE PHOTOS OF DAMAGE'

Insurance Council New Zealand chief executive Tim Grafton said it was too early to say how many insurance claims were made in the wake of Monday's storm.

He said if property had been damaged, people should take photos of it before making contact with their insurance provider.

If the property was uninhabitable, people could apply for alternative accommodation through their insurance provider.

“I can’t stress enough to look after your family, take pictures of damage and if any urgent repairs are needed then get that done but make sure to take photographs of the loss so it is easily processed by insurers."

A spokesman from Sydenham Quarter Incorporated, formerly the Sydenham Business and Commercial Association, said he had not been made aware of any Sydenham businesses receiving any extensive damage in the storm that would require them to shut down.

POWER CUTS

Orion spokeswoman Linda McGregor said about 1128 customers lost power due to the severe weather as of 2.30pm. All but 18 homes had their power restored as of 7.45pm.



Brooklands, Spencerville, Broadfield, Norwood, Rolleston, Springston, Burnham, Ellesmere, Irwell and Lincoln were affected.

She said most of the damaged lines appeared to be from vegetation and fallen trees colliding with powerlines.

Orion found lightning strikes damaged transformers in Selwyn, south of Christchurch, causing several hundred properties to lose power.

"We've identified the cause of the power going out in this area is transformer damage caused by lightning.

"We're checking each individual transformer, to locate those damaged that we will need to replace. Thanks for your patience."

She said four transformers needed to be replaced and crews would work late into Monday evening to have them operational, however, it was likely some homes may remain without power overnight.

Crews would return early on Tuesday morning if needed, McGregor said.

- Reporting by Jonathan Guildford, Sam Sherwood, Oliver Lewis, Jody O'Callaghan, Martin van Beynen, Cate Broughton and Charlie Gates





Jonathan Guildford 18:25 (1 hour ago) to Anna