cant say I have ever seen this phenomenon in Australia, though it sounds like something that could happen regularly.
Good footage. Fascinating!
I’ve see them, several of them on one day at Mt Hutt in Aug 2004. We were experiencing near-gale force conditions in the morning and early afternoon. The chairs were both closed. The gusts were stopping the TBars. I’m guessing NW gusts were hitting 100 km/h and the snownados were forming high on the front slope and then gradually advancing down to the day shelter. It certainly made for some exciting waits halfway up the TBar line!
As a BTW: In the end, the ensuing Blizzard shut (or shutt) the resort and road at 4pm, with all visitors holding up in the day shelter. In the end, we were allowed down at 10pm, with chains being fitted and removed by chain teams - incredible to watch! We had snow in Methven that morning and light flakes accumulating on the aircraft windows as we departed Christchurch. (Our visit winter NZ visit too!)
Given Hutt’s notoriety for wild weather, I’d be surprised if this doesn’t happen a few times per winter.
Maybe the Canterbury regulars lurking here know more about this phenomena?