A woman has described a tornado in Canterbury as a massive ball of dust coming at the road.

Lily Tworogal was driving to Christchurch with her father and was just north of Ashburton when she saw the tornado at about 4pm. Here is a video of what happened (warning there is some offensive language).

She said there had been a lightning storm just before she noticed the tornado.

"I just see this massive ball of dust swirling around, and very quickly it joins up with the sky to form what looks like a massive tornado basically, and it was moving fast and it was big and it was scary!"

Miss Tworogal said she had never seen anything like it before, and that it was extremely close to the road.

"I was yelling at dad to drive faster basically."

She said the tornado started to move towards the road and she just wanted to get away from it and they managed to pass it before it reached the road.

"It basically created a wall of dust so you couldn't see the road anymore ... it was pretty dramatic looking"

Miss Tworogal said that people who were travelling on the road had pulled over to the side.

She said it was a frightening experience and the tornado moved over farm land where there were structures.

Fire and Emergency have had no reports of damage.

MetService said the severe weather conditions were present for a tornado, but it could not confirm that one had occurred.

NIWA tweeted that lightning strikes were observed in the area.