Tornadoes;From start to finish Research Paper Example | Topics and Well Written Essays - 1000 words

Tornadoes;From start to finish - Research Paper Example They can wipe out an entire town in a matter of minutes. Scientists are still unclear as to the true cause of a tornado, but it usually forms when the cold polar air from Canada meets the warm tropical air from the Gulf of Mexico. Great instability is caused by the rising warm air; as a result, a giant rotating thunderstorm called a supercell is formed. Then, a squall line or narrow zone of cumulonimbus clouds appears. Lightning flashes, heavy rains, and hail begin to fall. After that, the funnel part of the tornado seems to descend from the base of the cumulonimbus clouds. But, this does not really happen. What really happens is the pressure within the cloud drops due to the increasing wind speeds. This is known as Bernoulli’s principle which states that as the speed of a moving fluid increases, the pressure within the fluid decreases (mitchellscience.com). As the pressure drops, it causes moisture in the air to condense. This action continues down the spiral, giving the impression that the funnel is descending from the cloud base . In addition to the visible funnel, there is also a hissing sound, which turns into a loud roar when the tornado touches the ground. Once the tornado reaches the ground, it starts to gather debris around it (ORACLE.ThinkQuest.org). This changes the color of the tornado. Tornadoes appear nearly transparent until they touch the ground and pick up dust and debris or a cloud forms in the funnel. Once they are formed, the average speed of a tornado is 30 miles per hour, but this may vary from stationary to 70 miles per hour. Tornadoes have been noted to move from Southwest to Northeast. But, they have also been known to move in any direction. Tornadoes move in a path that is controlled by the route of their parent thundercloud, and they often appear to hop. This happens when the vortex is disturbed. A vortex is easily disturbed, but it can also reform. This can also happen