No...it's definitely not a linear... But as I insinuated, I wasn't sure. Come to think about it, the relationship when increasing wind velocity and the amount of force the wind imparts on exposed surfaces, goes like: the lower end of cat 3 (111 mph) to the lower end of cat 1 (74 and change) doubles the amount of force

In any event, my apologies for not being more specific; the exact relationship formula has slipped my mind. If you go on the web and Google "wind speed to force relationship" or phrases similar, you can find material... Otherwise, I'm too lazy to go all the way down stairs and them through my old texts!