Types Of Tornadoes
Tornadoes: Also called twisters or cyclones, they are columns of air that are in contact with earth and a cumulonimbus; they cause destruction.
Dust Devils: Whirlwinds that form as a swirling updraft on sunny afternoons. They are practically harmless.
Waterspouts: vertical columns of spinning air; similar to tornadoes but formed over water.
Tornadoes start as a result of updrafts that form thunderstorms. The first stage of their development is called the whirl stage. When the vortex touches the ground, the organizing stage starts. Once the tornado is darkened by debris, we know that it has reached the mature stage. It begins to dissipate in the shrinking stage. It reaches the decaying stage once it can no longer be seen.
Dust devil formation
Dust devils form as a result of an updraft, but the updraft is not as powerful as those in a cumulonimbus cloud. They form in the afternoon when the ground has reached its highest temperature. The updraft occurs when the warm air from the ground rises. The horizontal winds that form the updraft into a weak vortex pick up dust and debris from the ground and they usually don't last over a minute. They are typically 15 feet in diameter.
These are weak forms of tornadoes that form over water. If the waterspout is strong, it's probably a tornado that formed over land and then moved into the water.