Trekking umbrellas are made specifically for trekking with the winds that rain brings .. they are vented, made of durable materials, can pack down small. Flying like Mary Poppins may be a great bit of fun actually, but the outdoor/ trekking gear companies that make these umbrellas most likely take the wind factor into consideration. They don't cause you to sweat as you walk, they are very protective from both the rain and the sun, they can attach to your pack to free your hands and keep your pack dry as well (although I do have a pack cover) ... seems like a win win all the way around imho.