Describe a time during the formation of hail stones when water releases energy. Sometimes, when ice crystals form in clouds and begin to fall, strong winds carry the ice crystals high into the clouds. When the crystals begin falling again, they grow larger as more water droplets freeze onto them. Clumps of ice, called hailstones, start to form. Eventually, the hailstones grow too heavy for the wind to carry and they fall to Earth.