Some of the dangers that exist with clouds you cant even see, which is why they can be the most dangerous. Know what to look out for!
Downdrafts are strong gusts of wind that come pummeling down towards the earth when cumulonimbus clouds are near the end of their life. In the beginning of their life, these clouds rise up into the atmosphere at several hundred miles per hour. Once they reach their mature phase, they then soon begin to pummel back down and break apart. When this happens, as the cloud is coming down, it is bringing with it all of the moisture it contained as well as pulling air currents towards the earth. This is particularly dangerous because this can cause very sudden high gusts of winds without warning, which can cause structural damage to houses, airplanes, telephone poles, and more.
Hail is when water droplets freeze inside of the cloud and then fall from it. Usually, hail is not that dangerous, being that they are usually only about the size of a grain of rice. On the contrary, hail can reach the size of ping pong balls, with the biggest ever recorded being a diameter of 8 inches and weighing two pounds! If something of this size, or even the size of a marble were to hit you in the head, it most certainly could cause a concussion. In addition, hail of this size can cause vehicle damage as well such as smashed windshields.
Tornados are particularly dangerous, as they possess the power to rip roofs right off of houses! Most of the time tornados come and go within a short amount of time, but can still cause loads of damage. These occur when hot and cold air meet and cause a wind "vortex", usually funneling down from a cumulonimbus cloud.