AtoxFT easiest way to tell which way the wind will be coming from is to be on the side of the walls where the levers are. I got this achievement just because of random chance early on (got behind walls early and fought to stay there).
Amusingly now I prefer to be on the opposite side of the walls where the wind is blowing, heh. A tip for either side of the walls: as long as there is enough to grab onto you can manually raise or lower the walls just by grabbing and pushing them (no lever needed).