Durb wrote:
The Class A motorhomes I have seen have their jacks mounted to the frame and are inboard of the tires. Jacks down in a storm would mean the coach is less likely to sway or bounce around, but is more likely to roll over with a high velocity side wind. If winds that extreme are forecast, move the rig nose first into the wind and slides in.
Assuming you didn't jack it up so the tires are off the ground, if it did start to roll, immediately, the tires would come into play the same as if you didn't have the jacks down...but you will have eliminated harmonic sway as the jacks aren't springy.