Pete Oswald said it was near white-out conditions at the top of Coronet Peak about 10am, when he decided to take a few runs in Exchange Drop.
As he started out he saw another skier who had lost his skis and was climbing back up to get them off a small ridge about 50m away.
Mr Oswald started to traverse the slope to help, but as he did, about 3m above him the snow "cracked off" and a slab of snow nearly 50cm deep took him down.
"It was a little bit scary to be honest," the seasoned skier said.
"I couldn’t tell — the visibility was so bad I didn’t know how far I was going to be going and it was deep enough that I had no control.
"I was trying to get my skis off, but I couldn’t do anything."
Because he had to climb to get to the start of his run yesterday, Mr Oswald had taken his avalanche airbag system off. Luckily, the avalanche was not big enough to bury him and he was able to sit up and ski out.
He retrieved the other skier’s pole, which was caught up in the slide, and the pair reported the incident to ski patrol.
Mr Oswald said he posted about his experience on social media in part because he knew he had been complacent about the inherent risks. He had not checked the NZ Avalanche Advisory by the Mountain Safety Council before setting out. He felt safe skiing at a resort.
Yesterday, the avalanche risk across most of the Southern Alps was listed as "high".
There were many different ways for snow to become unstable, Mr Oswald said.
On Thursday night, it became very cold, freezing the snowpack and snow accumulated unevenly on top of a hardened layer.
"Cold snow on ice doesn’t stick very well, generally," Mr Oswald said.
Telling others about his experience was "just an attempt to tell people to take it easy", he said.
"That’s the complacency; you make these assumptions that you’re safe and you can’t always make those assumptions."
An NZSki spokeswoman said there was a small "grade 1 avalanche release" at Coronet Peak yesterday.
"Patrol responded immediately with a partial closure to the affected terrain to allow a further check on snowpack stability.
"The skiers involved did the right, and expected, thing by reporting the incident to patrol."
As a result of 15cm to 20cm of new snow and windy conditions, yesterday’s snow report asked skiers to be wary of natural hazards, the spokeswoman said.
