Classification Schemes: A Look at Tornadoes. Elizabeth Hoffman- Lohmeyer October 26, 2010 Syracuse University Professor Barbara Kwasnik : IST 616. Tornadoes.
Elizabeth Hoffman-Lohmeyer October 26, 2010
Professor Barbara Kwasnik: IST 616
Domain & Scope country. Approximately 1,200 tornadoes hit the U.S. each year.
In 1971, University of Chicago meteorologist Dr. T. Theodore Fujita developed the Fujita Tornado Damage Scale. In 2007, this scale was updated by a team of meteorologists and wind engineers. The new scale is referred to as the Enhanced Fujita Tornado Damage Scale.
The domain for classifying tornadoes is very specific. The entities being classified are tornadoes. The Enhanced Fujita Scale (EF Scale) measures two things: 1. The estimated wind speed of a tornado, and 2. The level of damage the tornado causes. The scope of the EF Scale is limited to tornadoes only. It does not apply to storms such as hurricanes.
Dr. Ted Fujita
Source: University of Chicago
Explanation of Structure for the Enhanced Fujita Scale country. Approximately 1,200 tornadoes hit the U.S. each year.
This chart shows the comparison between the original Fujita Scale and the Enhanced Fujita Scale which went into effect in 2007.
The EF Scale incorporates damage indicators which allows for more detailed analysis and improved correlation between damage and wind speed than the original Fujita Scale.
The chart on the left is an example of one of the 28 different types of construction that are used as indicators for tornado damage.
Summary more detailed analysis and improved correlation between damage and wind speed than the original Fujita Scale.
The Fujita Scale is a great example of a classification system that has changed over time due to its weaknesses. The original scale did not take into account the differences in damage to various types of structures and did not contain specific damage indicators. There was no correlation between damage and wind speed.
In response to this, the Enhanced Fujita Scale was developed. This new classification system is much more consistent and contains detailed descriptions of damage (including damage to vegetation) which was not available in the earlier scale.
As a result of these changes, the EF Scale is a powerful tool that provides accurate and specific documentation of tornadoes.
Sources Consulted more detailed analysis and improved correlation between damage and wind speed than the original Fujita Scale.
Doeden, M. (2008). Tornadoes. Minneapolis: Lerner Publications Company.
The Enhanced Fujita Tornado Scale. (2008). Retrieved October 8, 2010, from NOAA Satellite and
Information Service website: http://www.ncdc.noaa.gov/oa/satellite/satelliteseye/educational/
The Fujita Scale. (1999). Retrieved October 5, 2010, from The Tornade Project website:
Fujita Tornado Damage Scale. (2010). Retrieved October 10, 2010, from The National Weather
Service website: http://www.spc.noaa.gov/faq/tornado/f-scale.html
Orme, D., & Orme, H. (2005). Tornadoes. Danbury, CT: Children's Press.
Prokos, A. (2009). Tornadoes. Pleasantville, NY: Gareth Stevens Publishing.