Footage of the tornado hitting the roof was posted on Twitter.

Footage of the tornado hitting the roof was posted on Twitter.
A large waterspout has been spotted off the Canterbury coast as an intense thunderstorm cell moves offshore.

The footage was taken at Pines Beach North Canterbury this afternoon shortly after a tornado ripped through Sydenham in Christchurch leaving two people hospitalised.

1 NEWS meteorologist Dan Corbett explained the conditions leading up to the wild weather this afternoon.

"Conditions were perfect for making a thunderstorm with very cold air in the atmosphere, then the southerly winds down low went up and met the cold air above.




"The unstable air then mixed with some spinning clouds that caused conditions to create a tornado.

"The thunderstorm cell has now moved offshore, but unstable conditions will still exist for the next few hours," Corbett warns.

In another incident, Fire and Emergency NZ attended a crash near Dunsandal south of Christchurch at 1.30pm which they assume was related to the southerly weather system that whipped through Canterbury.

Two people were initially trapped and suffered serious injuries in the crash with one being transported by helicopter to Christchurch Hospital.

Shortly after lightning strikes caused a number of hedge and scrub fires to the East between State Highway one and the township of Leeston.