Super+Tornado+Outbreak+(1974)

Nick Nacion = = =Introduction=

The year of 1973, had became known as the year of the tornado. Over 1,100 tornadoes were reported that year. But the following year produced a more devastating disaster. The Super Tornado Outbreak of 1974 was a catastrophic event and the worst tornado outbreak in the history of the United States. This outbreak contained 148 tornados that spread across 13 states (Alabama, Georgia, Illinois, Indiana, Kentucky, Michigan, Mississippi, North Carolina, Ohio, South Carolina, Tennessee, Virginia, and West Virginia.) It occurred from April 3rd to 4th in 1974. Major tornado activity occurred between 2PM and 10PM of April 3rd. Out of 148 tornadoes, 118 of these tornadoes had paths of over one mile long.
 * < [[image:http://upload.wikimedia.org/wikipedia/commons/9/9c/Super_Outbreak_Map.PNG width="320" height="388" align="center"]] ||
 * < //Map showing paths of tornadoes from the outbreak.// ||


 * [[image:http://www.publicaffairs.noaa.gov/storms/images/sat0474.gif width="448" height="334"]] ||
 * //Clouds over the U.S on April 3rd, 1974, the day of the outbreak.// ||

=What is a tornado?=

Tornadoes are frequently occurring natural events that are capable of great destruction. A tornado is defined as "a mobile, destructive vortex of violently rotating winds having the appearance of a funnel-shaped cloud and advancing beneath a large storm system." They are occur most frequently in the United States, east of the Rocky Mountains during Spring and Summer. Tornadoes are extremely destructive natural occurrences, and are characterized by their dark funnel-shaped appearance that contain extremely fast twirling winds. Some of the most destructive tornadoes can reach wind speeds of over 250 miles per hour.

Classification
Tornadoes are classified accordingly by the Fujita Scale, a scale developed by T. Theodore Fujita of the University of Chicago in 1971. This scale classifies tornadoes based on the amount of damage it causes. The scale ranges from F0, being light damage, through F5, being incredible damage.
 * SCALE || WIND ESTIMATE (MPH) || TYPICAL DAMAGE ||
 * F0 || < 73 || Light damage. Some damage to chimneys; branches broken off trees; shallow-rooted trees pushed over; sign boards damaged. ||
 * F1 || 73-112 || Moderate damage. Peels surface off roofs; mobile homes pushed off foundations or overturned; moving autos blown off roads. ||
 * F2 || 113-157 || 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. ||
 * F3 || 158-206 || 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. ||
 * <span style="font-family: Arial,Helvetica,sans-serif; font-size: 110%;">F4 || <span style="font-family: Arial,Helvetica,sans-serif; font-size: 110%;">207-260 || <span style="font-family: Arial,Helvetica,sans-serif; font-size: 110%;">Devastating damage. Well-constructed houses leveled; structures with weak foundations blown away some distance; cars thrown and large missiles generated. ||
 * <span style="font-family: Arial,Helvetica,sans-serif; font-size: 110%;">F5 || <span style="font-family: Arial,Helvetica,sans-serif; font-size: 110%;">261-318 || <span style="font-family: Arial,Helvetica,sans-serif; font-size: 110%;">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. ||


 * [[image:http://www.nssl.noaa.gov/headlines/images/dsz8.jpg width="640" height="424"]] ||
 * //Photo of a tornado in central Oklahoma on May 3rd, 1999.// ||

=What causes tornadoes?=

Tornadoes are caused by thunderstorms. A thunderstorms is "a storm with thunder and lightning and typically also heavy rain or hail." Much about their formation is still not understood due to their unpredictable occurrences and the danger in getting close to them. Because of their destructive natural and the risk of injury, it is difficult to obtain data from around, or inside of the tornado. It is believed that their rotation is caused by winds at different altitudes, blowing at different speeds which creates a what is a called a wind shear. If this rotation becomes caught in the storms updraft, it can tighten causing the wind speed to increase, which then can create the funnel cloud of the tornado.

Works Cited http://www.spc.noaa.gov/faq/tornado/f-scale.html http://upload.wikimedia.org/wikipedia/commons/9/9c/Super_Outbreak_Map.PNG http://www.publicaffairs.noaa.gov/storms/description.html http://www.publicaffairs.noaa.gov/storms/satimages.html http://www.publicaffairs.noaa.gov/storms/sattech.html http://www.publicaffairs.noaa.gov/storms/ http://www.nssl.noaa.gov/edu/safety/tornadoguide.html http://eo.ucar.edu/kids/dangerwx/tornado3.htm http://www.nssl.noaa.gov/headlines/images/dsz8.jpg http://www.nssl.noaa.gov/headlines/dszpics.html