Besides major wind systems on the earth's surface, there are certain types of winds, even though on a much smaller scale, which are produced by the topographical peculiarities or local temperature differences. Since these wind systems are generated by purely local factors and their zone of influence is quite limited, they are termed as local winds. They play an important role in the weather and climate of a particular locality. The waterspout is one of the natural phenomena which is also associated with the wind system.
What is waterspout?
The spiral or circular movement of mist and air that form over oceans, seas, lakes and harbours especially during warm seasons is called waterspout. It is natural phenomenon which generally occurs in the tropic and subtropics region. Although water-vapour content forms only a small proportion by volume of the atmosphere, it is the most important constituent of air in deciding weather and climate.
Formation of Waterspouts
The formation of waterspout requires extremely intense level of humidity and warm temperature of water which is accompanied by the five stages which are given below:
1. Dark spot: In this stage, the surface of the water takes on a dark appearance where the vortex, or column of rotating wind, reaches it.
2. Spiral patter: In this stage, . Light and dark bands spiral out from the dark spot.
3. Spray ring: In this state, swirling rings of sea spray forms around the dark spot. It appears to have an eye at the centre, similar to that seen in a hurricane.
4. Mature vortex: In this stage, the waterspout is now at its most intense stage, visible from the surface of the water to the clouds overhead. It appears to have a hollow funnel and may be surrounded by vapour.
5. Decay: In this stage, the flow of warm air into the vortex weakens, the waterspout collapses.
Types of Waterspout
1. Fair weather waterspout: It is generally form along the dark flat base of embryonic column of cloud. It is not so intense because it develops on the surface of the water and move upwards.
2. Tornadic waterspout: It is form over water or move from land to water. It is very intense because it is accompanied by high winds and seas, large hail, and frequent dangerous lightning. It is associated with thunderstorm. It forms as a vertical shape of a coil column of mist and air from severe thunderstorm clouds to a water body.
3. Winter waterspouts: It is also known as a snow devil, an icespout, an ice devil, a snownado, or a snowspout. This type of waterspout formation is very rare especially under the base of a snow squall. It is formed when air moves across the steam comes from the extremely cold water.
Difference between hurricane and waterspout
Hurricane is a severe tropical cyclone usually with heavy rains and winds moving at 73-136 knots. Whereas waterspout is that hurricane is a severe tropical cyclone in the North Atlantic Ocean, Caribbean Sea, Gulf of Mexico, or in the eastern north, and pacific off the west coast of Mexico.
Difference between cyclone and waterspout
Waterspout is a tornado that occurs over a body of water whereas cyclone is a system of winds rotating around a centre of low atmospheric pressure.