I rode out the June 29, 2012 Derecho in my Class C, a storm that originated in the midwest, rolled through the DC area, across Delaware Bay and then southern NJ, where I was parked in in the NJMP paddock for a race that weekend. It hit at about midnight with straightline winds estimated at 70-80 mph. I was fortunately parked in close proximity to others, with my enclosed trailer still hitched to the RV, oriented purely by luck so the winds coming from the rear.
It was a hell of a rock and roll for about 30 minutes until the front passed through. My 16 year old son and I sat on the floor for the duration. I was most worked about flying shrapnel from awnings and canopies, and there were plenty that were ripped to shreds. I was lucky someone near where I was parked, from the DC area, who had gotten a call from his wife letting him know they had just gotten blasted and it was heading our way, so I packed up anything that I had outside.
I've been through plenty of severe thunderstorms, even in the midwest, but never anythiing like that.