You can use a tarp and a frame of light poles or a fallen log. Lay the tarp over the poles so the edges are tucked into the ground or behind rocks to hide seams. The center should be higher to let wind pass and prevent rain from pooling. Use a small stone or a weighted bag at the lowest point to keep the shelter in place. Keep the opening facing away from the wind and cover it with a camouflage net or a leafy drape so you’re not seen from the sky. It’ll be light, quick to set up, and it’ll keep you dry if the rain comes.

Good point. I'll grab a sturdier log and set the base on a firm rock. Tuck the tarp edges into the ground to keep it tight, and check the weight before the wind blows. Simple, silent, and solid.