Its not the wind speed that matters so much - but the quality of the wind.
You realize this when you live inland - in crappy winds and then vacation at the beach - with smooth winds.
In smooth winds you can fly a STD in very light conditions ... whereas in land you'd be using a UL or SUL.
But about 10mph tricking becomes increasingly more problematic ... with some kites prone to "powering up" resulting in excessive speed or pull.
Of course that varies from kite to kite, the SuperFly is great in 12mph - the BMK Exile is bit of a handful.
And much above 15mph its really not worth the effort - not for me anyways.
I think the quality of the wind sums it up perfectly and the big gust that traashed the kite is a perfect example of that.
Even though I had been flying in higher wind speeds with gusts up to 18mph that had not hit me at such a critical time, still it's all learning and experiance for me.
Brookite Typhoon, HQ Tramontana retro, HQ Maestro II PAW/ Steve C modded, Monster, Benson Deep Space custom.
Some of the gear, no idea.