It all happened as the Mid Canterbury farmer worked on his property, close to State Highway 1 just north of Ashburton on Sunday as Canterbury’s long anniversary weekend travellers were returning home from holiday.
“It was lucky really it was Sunday as I was the only one on the farm at the time,” Hanrahan said.
“It was also very lucky that it stopped just short of the main road as landing a centre pivot in the middle of State Highway 1 on a busy holiday weekend would have been a huge disaster.”
Hanrahan was working on his farm when shortly before 4pm the wind changed.
“There was a southerly arriving in one end of the paddock and a northeasterly at the other end. They met in a barley paddock and moved into the potato paddock and that’s what set the dust twister up.
“It started right beside me, like a whirlwind – it just grew bigger and bigger.
“I’m not sure what I was thinking at the time. I just thought I need to video this.”
Hanrahan was about 100 metres away.
“I saw it come across the yard, skirt the farmhouse and head on across the paddocks. It must have trekked about 2.5km across the farm.
“Wrap was ripped off a silage stack, tyres were flying through the air, it was unreal, like a huge plume of dust rising and twisting up and up as it moved along the farm and into the neighbour before breaking up just short of the main road – thank goodness for that.”
Five spans of an irrigator were upended from its centre point and left twisted and mangled while a second irrigator was bent in half.
A trailing mower attached the tractor was picked up and turned 90 degrees before being dropped and left on its end.
The tractor windows were smashed.
“I guess these disaster events happen at the weekend for a reason.
“I was the only one on the farm being a long weekend and a Sunday.
“If it had been a week day it would have been quite different. I would have had a few staff, weather permitting, planting spuds in that paddock this week.
“There could have been a lot more than soil picked up had it been during the week.”
Insurance assessors and irrigation company technicians have been on site this week but Hanrahan is yet to hear what might be salvageable and to what extent his insurance claim is likely to be.
“There’s been significant damage but I have no idea what value the claim will be at this stage. I just wouldn’t even want to put a figure on it. I’ll just wait until the assessors get back to me.”
The micro-tornado, described by the weather gurus as a dust devil, happens in specific weather circumstances.
As the ground heats up the rising air can create a vortex that picks up loose soil and whirls it up into the air.
“That’s just exactly what happened once it hit the spud paddock,” Hanrahan said.
The tornado and its associated rain and hail signalled the arrival of a complex weather system, prompting severe weather warnings as it makes it way over the South Island, plummeting temperatures and dumping snow and heavy rain across most of the island in what MetService predicts will deliver an extended period of wet and cold weather until the end of the week.
