According to Websters Dictionary, a tornado is a rotating column of air accompanied by a funnel shaped downward extension of a cumulonimbus cloud and having a vortex several hundred yards in diameter whirling destructively at speeds of up to three hundred miles per hour. There are six classifications of tornadoes, which are measured on what is known as the Fujita Scale. These tornadoes range from an F0 to an F5, which is the most devastating of all. Abnormal warm, humid, and oppressive weather usually precede the formation of a tornado. Records of American tornadoes date back to 1804 and have been known to occur in every state of the United States.
A tornado outbreak occurs when a large number (six or more) of tornadoes are formed in groups or individual storms within a 24-48-hour period over a specific geographical area and spawned from the same general weather system. The April 3-4 outbreak of 1974 was the worst in the United States recorded history. Never before had so many tornadoes brought so much destruction to such a wide area of this country. It was so bad that a name had to be found for it. “Super Outbreak” is what they came up with. This storm, which extended from the afternoon of April 3rd through the morning of April 4th, produced 148 tornadoes in thirteen states.
Xenia, Ohio was home to the worst damage caused by the tornado outbreak of 1974. As school children in Xenia, Ohio waited for their ride home and workers watched the clock tick slowly towards quitting time, a monstrous tornado whipped wildly towards their small town. In just minutes, the small peaceful city of Xenia became ground zero for the nation’s worst tornado outbreak.
The tornado, an F5, was among the strongest ever witnessed, with winds estimated between 261 and 318 mph. It sped furiously across town at a speed of about 52 mph. frantic residents scrambled for cover as the twister’s shrieking winds slammed the historic Xenia Hotel. The tornado showed no mercy yanking thick trees from the ground, cars from the streets, and people from their homes. It tossed two tractor-trailers 150 feet into the air and onto the roof of a bowling alley. A wooden utility pole about 20 feet long snapped in half like a twig and soared 160 feet away from its original location. Five schools in Xenia were in the direct path of the tornado. When the tornado passed, three of the schools were destroyed almost completely. The other two were extensively damaged. The devastating tornado that struck Xenia killed 37 people, injured 2,000, and damaged 7,000 homes.
In the Xenia tornado, as in any major disaster, the damage to buildings and lifelines and the effort required responding to casualties and destruction significantly disrupted traditional group activities in all spheres of life, from work to recreation, from religious worship to banking services. A tornado does more than wreck buildings and sever lifelines, it completely interrupts the cycles of community life, or at least puts considerable strain on them. With stores and places of employment closed in Xenia, not only were some people temporarily unemployed, but necessary goods and services could not be obtained in the usual ways at the times and locations wanted. With so many schools destroyed, educational schedules were sharply altered, as were recreational habits for children. Ultimately, the tornado very sharply disrupted community life.
So what exactly was the cause of the Super Tornado Outbreak of 1974? The approximate cause of the huge tornado outbreak of April 3-4, 1974, in roughly layman’s language, was the result of a number of important factors coming together at the right critical time. A very vigorous upper level atmospheric disturbance, along with a strong polar jet stream lead to the amplification and general strengthening of a low pressure region to the east of the Rocky Mountains. As this low pressure region, with its counterclockwise rotation moved eastward, it became more and more intense and caused a great deal of warm, moist air to move into the Ohio river valley from the Gulf of Mexico. The natural rising of the surface, warm, moist air was inhibited by an upper atmospheric layer of warm dry air from the dry southwest region of the country.
During the outbreak, six tornadoes reached the massive intensity of F5 on the Fujita Scale, were winds can exceed 318 mph and whole houses can be swept away. Often there isn’t an F5 in an entire year in the whole country. An estimated 118 of the twisters had paths on the ground more than a mile long. One traveled more than a hundred miles, researchers say. Another reached five miles in width. At one point, 15 tornadoes were on the ground at the same time. Few states in the region escaped damage; those hit were Alabama, Georgia, Illinois, Indiana, Kentucky, Michigan, Mississippi, North Carolina, Ohio, South Carolina, Tennessee, Virginia, and West Virginia.
In conclusion, the deadliest and most devastating U.S. tornado outbreak of the 20th century was the April 34, 1974, Super Tornado Outbreak. It lasted 16 hours and at least 148 twisters tore up 2,500 miles of Earth through 13 states over a 24-hour period, according to the National Weather Service. The “super outbreak,” as meteorologists now call it, left 330 people dead and 5,484 injured. Property losses were placed at $600 million and only ten of the thirteen states that were hit, were declared a disaster area.
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Snowden, Flora D. Tornadoes of the United States. University of Oklahoma Press: Norman, 1953.
White, Robert M. The Widespread Tornado Outbreak of April 3-4, 1974. Rockville, Md. 1974.