Rare tornado hits Canterbury as complex weather system moves over New Zealand

A severe storm accompanied by hailstones the size of marbles and at least one large tornado hit Canterbury, New Zealand on November 18, 2018. Some of the residents described the tornado as a massive ball of dust coming at the road. The country is currently under the influence of a complex weather system, bringing an extended period of wet and cold weather. The calendar says spring, but Mother Nature says it's winter, NIWA said. Surprisingly, the main focus of this weather event is snow.

The tornado was captured by local resident Alesha Plew as she and her husband Richard were driving along State Highway 1 north of Ashburton, the NZHerald reports.

"My husband looked up and just said… what is that? It was just a massive tornado, a big brown twister."

"We drove through a severe hailstorm in Ashburton, before the skies cleared and then the twister appeared in a paddock beside us. We kind of kept driving straight past it – it was a couple of fields away from us at the time," she said. "It ended up coming about 10 m [33 feet] from the car, and there was debris and dirt flying around. While it looked dangerous, it didn't feel that way – it didn't feel like it was sucking us in, anyway."

MetService meteorologist Brian Mercer said about half a dozen people had contacted them about the tornado.

Cold air was moving up from the south and mixing with northwesterly winds, which created a twisting motion in the winds that could lead to a tornado, he said.

"They can happen, but they're quite rare," he said. New Zealand's landscape lacked large open plains found elsewhere in the world, meaning any tornadoes that did occur did not last long.

Calendar says late spring, but Mother Nature says it's winter, NIWA said as MetService issued a Severe Weather Warning for heavy snow for inland Southland, Central Otago and inland Clutha on Sunday evening (LT). 

"Following a mild week of weather, with plenty of sun about, this weekend has seen the skies greying over and rain spreading across the country," MetService said.

The service is forecasting a complex weather system to move over the country over the next few days, bringing an extended period of wet and cold weather. 

"Most people can expect to see some rain over the next few days," meteorologist Tui McInnes said. "However, snow is surprisingly the main focus of this event."

Considering we are at the end of spring and on the cusp of the summer months, snow is not something typically thought of at this point. "While not unheard of, snow is uncommon this late into the year," McInnes comments.

Snow levels are set to lower significantly for the South Island, with a dusting even possible for Central Plateau.

"Cold temperatures associated with this weather system means we could see snow to 400 m  in Southland and 500 m in Otago and Canterbury," McInnes says, "and there are a handful of  Severe Weather Warnings and Watches in place, so this is certainly an event  to stay up to date with."

MetService is forecasting a risk of hail also, which could impact horticultural regions.

"This weather brings unstable air with it, prime  conditions for hail showers," explains McInnes, reminding to once again "stay tuned with the latest forecasts and remain alert on the inclement  weather."

Featured image: Tornado in Canterbury, New Zealand on November 18, 2018. Credit: Alesha Plew