Tornado Formation - Dangerous Wonders
Essay by nikky • December 1, 2011 • Essay • 1,257 Words (6 Pages) • 1,857 Views
Dangerous Wonders
A tornado is defined as a violently rotating column of air extending from the base of a thunderstorm down to the ground. Tornados, commonly known as twisters, are dangerous monsters that destroy everything in their path. However, at the same time they can be a wondrous phenomenon. Not all storms form tornados and not all tornados are formed from storms, however, most tornado seemed to be formed from super cell thunderstorms.
A mesocyclone is a vortex within a storm. A super cell is a storm that contains a mesocyclone at its core. When these condition form there is usually a good chance that a tornado will form. According to The Storm Chasers, from The Discovery Chanel, the first factor that must be present is wind shear and updraft. An updraft is a difference in the wind speed at varying altitudes or directions. As the thunderstorm begins to form the updraft helps start the horizontal spin. Also the super cell must raise, sustain, and tighten the central vortex. If these steps succeed it will create whirling in the mesocyclone. This creates a balance between the inward and outward flow of air, know as a dynamic pipe effect, initiating the spinning of the wind.
The next factor in the formation is the difference in air temperature. Most tornados form when cold and hot air meet. Where the two air masses meet , they starts fueling the updraft pulling more warm air up, adding to the spinning motion. Then the warm air reaches the top, spilling over the back and pushing the warm air into the storm.
After the warm air is recycled back into the storm, the moisture and instability in the air is the next step that takes action. Moisture must be abundant in the warm air for a tornado formation to occur. When the air begins to rise, its dew point lowers and the moisture cools and condenses to cause the storm cloud to grow stronger. Water vapor then releases heat fueling the spinning cycle. Instability, the difference between temperature and moisture levels in the air, works to intensify the storm.
Last, gravity waves move through the storm, cause a funnel to form. The tornado may be unseen until it captures dirt and debris. Even though you may not see the tornado forming right away, there is no doubt that you will hear a large tornado when it forms. There are also others sign to indicate that a tornado may form, such as; the sky may turn a yellow color, if you are expecting severe weather hail can be a danger sign, and also wall clouds are commonly seen where tornadoes form. If the tornado never touches the ground but hangs suspended in the air, it is called a funnel cloud. For it to be a true tornado, the funnel must touch the ground at some point. Although it may not stay on the ground for a long period it is still considered a tornado. Funnels may also cause damage, even though they do not touch the ground.
All tornados are formed the same way. However, some can be more powerful, and they have a wide variety of speeds, sizes, and the times that they last. In 1971, Dr. Theodore Fujita, created a way to rank tornadoes, called the F-Scale. In the F-Scale, tornadoes are ranked from F0 to F5, F0 being the mildest and F5 being the most dangerous. A F5 tornado causes extreme damage and can lift house off of their foundations and carry them a considerable distance, and can also carry cars as far as a 100 meters. (Col). Although F5 tornadoes are rare, they are something that causes wide spread fear and can wipe out whole towns, such as Greenburg, KS. Yet only 2% of tornadoes are "violent" tornadoes. However, these violent tornadoes
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