I have heard of skylights going flying with strong winds though...[/QUOTE]
The skylight flying away shows the secret function of the Mongolian roof-flap:
Since the wind passing over the curved yurt-roof will create suction, the yurt as a whole tends to fly away. The Mongolian roof-flap opening lets air/pressure escape from the inside, refilling that vacuum, preventing lift-off.
Inside the yurt the sudden pressure-drop can create very sudden and short-lived condensation-clouds, it is amazing to see.
So here's my two cents: If you are in a stormy place with a plastic dome
, dont screw it down, make so it can open/fly. If the skylight is made of polycarbonate, it will survive a bit of airborne.
Maybe secure it with a piece of rope, but don't screw it down!