en.wikipedia.org/wiki/Katabatic_windThey wait until they get a clear indication that a catabtic wind has started, you can see it in some of their vids, that light mist flowing down the mountain. Or the reverse, where there is a light wind blowing up the valley, they are kiting in. Chasta and the Ozone guys are super careful to pick the ideal winds for these film shoots and for all their 'big' kite snowkiting.
The guys know how to kite for sure, they demonstrate exceptional kite handling skills, and they are equipped with the best, most thoroughly researched and developed kites in the world, by Ozone!
Yeah I reckon its 8-12 knots, no more.
Cya and
Goodwinds
Steve