The two most famous tornadoes in popular culture are probably from “The Wizard of Oz” and “Twister”. Modern fascination with these storms really started on May 10th, 1996, when “Twister” was released; ever since then, the idea of storm chasing, as it’s called, has become a big business, with several TV shows about tornado chasing.
What is it about this phenomenon of weather that has us so interested? That is what this article will explore.
A tornado, from the Latin “tornare” (“to thunder”), is simply a column of wind twisting around an area of low atmospheric pressure, narrowing as it reaches the ground. Tornadoes are born from thunderstorm clouds, and are generally 200 to 300 yards in diameter. The can reach 250 miles per hour, and its path of destruction can reach over 1 mile wide and 50 miles long. They can go further though—one tornado dropped debris over 30 miles away!
What causes tornadoes? It all starts with an innocent violent thunderstorm. When, in the lower atmosphere, there is instability (warmer and more humid than usual conditions) and windshear (rapidly accelerating windspeed and direction, increasing with altitude). These two factors come together, and the tornado forms as the wind twists around the center vortex, and there you are-one tornado. Then there are waterspouts. Waterspouts are not technically tornadoes, but are simmilar.
There are two kinds of waterspouts. “Tornatic Waterspouts” are regular tornadoes that have moved out over water. “Fair Weather Waterspouts”, the less dangerous kind, form over water in simmilar curcumstances as tornadoes. This is the more common type.
Tornadoes are divided into 3 catagories: Weak, Strong, and Violent. Sixty-nine percent of all tornadoes are weak, and last only about one minute. Violent tornadoes comprise only 2 percent of all tornadoes, but could last for over an hour.
Tornadoes can happen anywhere in the country and at any time of the year, but one section of the US—called Tornado Alley—gets more than anywhere else. There is no exact definition of what this area is, but it generally is considered to be in the Plains States between the Appalachian and Rocky Mountains. According to a National Climatic Data Center report, between January 1, 1950 and July 1, 2009, Oklahoma reported the greatest number of tornadoes, at 9342.
Another thing about tornadoes is they are catagorized by severity, much like earthquakes have the Richter Scale. The Fujita Scale (F Scale) was developed in 1971 and is based on the wind speeds and severity of damage the tornado makes to man-made structures. The lowest level is an F0 storm, a gale tornado, one which has wind speeds of 40-72 miles per hour. The damage here includes broken branches and damage to chimneys. The scale goes up to an F6 storm, an inconcievable tornado, which has windspeeds of 319-319mph. This storm is nearly impossible to happen, and damage would be indetectable among an F4 or F5 storm.
If you find yourself caught in a tornado, seek shelter immediately. When in a building, get to the lowest level as safely as possible, either a basement or storm shelter. If that's not possible, get to the center room, away from windows and outside doors, and don't open the windows. If in your car, get inside. If you're outside, and can't get into the building, then lay flat in a ditch and cover your head. Don't go under a bridge.
The good news is, if you do experience damage in a tornado, most homeowners policies will cover it. And your comprehensive auto insurance will cover any damage to your car.