What is a Tornado? A tornado is an etremely intense windstorm known by a twisting, funnel-shaped cloud. The word "tornado" comes from the Spanish or Portuguese verb tornar, meaning "to turn." The event appears in storms all around the world, though they most commonly occur in a broad area of the American Midwest and South known as Tornado Alley, but some other countries see the storms occur in even higher densities. Tornadoes form from severe thunderstorms, usually spawned from squall lines and supercell thunderstorms, though they sometimes happen as a result of a hurricane. They are believed to be produced when cool air over takes a layer of warm air, forcing the warm air to rise rapidly.
How big can a Tornado get? The method for measuring tornadoes is known as the Fujita scale. The Fujita scale rates a tornado's intensity by the damage it inflicts on human-built structures and if measurable - it's wind speed. It was introduced in 1971 by T. Theodore Fujita of the University of Chicago. Here's how it works. - F-0 - Wind speeds up to 73 miles per hour (<115 km/h). Light damage. Some damage to chimneys; branches broken off trees; shallow-rooted trees pushed over; sign boards damaged.
- F-1 - Wind speeds 73 to 112 miles per hour (116-180 km/h). Moderate damage. Peels surface off roofs; mobile homes pushed off foundations or overturned; moving autos blown off roads.
- F-2 - Wind speeds 113 to 157 miles per hour (181-250 km/h). Considerable damage. Roofs torn off frame houses; mobile homes demolished; boxcars overturned; large trees snapped or uprooted; light-object missiles generated; cars lifted off ground.
- F-3 - Wind speeds 158 to 206 miles per hour. 251-330 km/h). Severe damage. Roofs and some walls torn off well-constructed houses; trains overturned; most trees in forest uprooted; heavy cars lifted off the ground and thrown.
- F-4 - Wind speeds 207 to 260 miles per hour. (331-415 km/h). Devastating damage. Well-constructed houses leveled; structures with weak foundations blown away some distance; cars thrown and large missiles generated.
- F-5 - Wind speeds 261 to 318 miles per hour. (416-510 km/h). Incredible damage. Strong frame houses leveled off foundations and swept away; automobile-sized missiles fly through the air in excess of 100 meters (109 yds); trees debarked; incredible phenomena will occur. The movie"Twister" refers to an F5 as "The Finger of God", referring to the mental imagery of God draging a finger across the Earth, wiping out everything that was in its path.
Of all tornadoes formed in the US, F0 and F1 tornadoes account for a large percentage of occurrences. On the other end of the scale, the massively destructive F5 tornadoes account for less than 2% of all tornadoes in the US.
How often do Tornadoes occur? The United States experiences by far the most tornadoes of any country, and has also suffered the most intense ones. However, tornadoes do occur throughout the world; the most tornado-prone region of the world, as measured by number of tornadoes per unit area, is the United Kingdom, especially England. In Canada, an average of 80 tornadoes occur annually, killing 2, injuring 20 and causing tens of millions of dollars in damage. On average, the United States experiences 100,000 thunderstorms each year, resulting in over 1,000 tornadoes and approximately 50 deaths per year. What is the worst recorded Tornado in US history? The Tri-State Tornado as it is known. At About 1:00 PM on March 18, 1925, trees began to snap north-northwest of Ellington, Missouri, and for the next three and a half hours more people would die, more schools would be destroyed, more students and farm owners would be killed, and more deaths would occur in a single city than from any other tornado in U.S. history. Records would be set for speed, path length, and probably for other categories that can't be measured so far in the past.
Without todays modern weather surveilence equipment, these people were totally blindsided by the storm. The aftermath was devestating. 695 dead, and over 2000 injured. Millions in total damage, and thousands of homes completely destroyed. More than six tornadoes in one day is considered a tornado outbreak. The biggest tornado outbreak on record—with 148 tornadoes, including six F5 and 30 F4 tornado's - occurred on April 3, 1974 What is protecting us from "the dark side of nature"? Modern science, early detection, and advanced warning.
Each time tornado season comes around, schools and media outlets in tornado-prone areas spend time educating the public about the dangers and what can be done to improve the chances of surviving a storm. In the United States, citizens are often advised to purchase NOAA Weather Radios. They are relatively inexpensive devices costing as little as US$20 which will activate whenever the National Weather Service issues severe weather warnings. Warnings are also carried on radio and television, and most communities have civil defense sirens that will activate when severe weather is believed to be approaching.
There is no way to be sure how many lives have been saved due to all the advances in weather technology, but it numbers in the thousands per year.
According to Environment Canada, the chances of being killed by a tornado are 12 million to 1 (12,000,000:1). One may revise this yearly and/or regionally, but the probability may be factually stated to be low. Tornadoes do cause millions of dollars in damage, both economic and physical, displacement, and many injuries every year.
-=> Discuss this article on the Message Boards!
-=> Didn't find what you're looking for? Try Searching Armageddon Online!
-=> Spot a typo or have a general question? Use the Contact Forms to get your mesage out there!
|
