Transcript Tornados
The tornado seen in the Wizard of Oz was actually created from an enormous wind sock that was sprayed with dust and dirt A tornado is formed from a Supercell (thunderstorm on steroids) The warm air rises and cold air sinks when the currents violently clash into each other. This storm system is massive; towers up high into the Stratosphere from 35,000- 60,000 ft (more than twice the height of Mt. Everest) As the air rises it is met by different winds at different elevations blowing from all different sorts of directions causing the air to begin to rotate and filling the storm with explosive energy As the winds spin the air, the airspeed increases causing the air to spin faster, thus creating a rolling effect that is horizontal to the ground. The rolling air is then tilted vertical creating an area of rotation called Mesocyclone This is usually where the tornado forms Large scale, long lived, right moving, damaging thunderstorm that can last for hours Winds inside supercell rise at 100 mph or even faster The entire system can move horizontally at speeds up to 75 mph Like a greedy monster; feeds on other storm system that are miles away The supercell releases energy equivalent to 20,000 tons of TNT every second: about the same energy as the atomic bomb Have recognizable features In the middle of the supercell is this strongest point of system known as the wall cloud which produces the most precipitation and is the place most likely to produce tornadoes The overshooting top: caused by powerfully draw warm, wet air up; strong currents burst through and overshoot which creates a dome. The anvil (shaped like a blacksmiths anvil) is formed at higher altitudes where the air is thin and temperatures are far below zero where water vapor turns to ice crystals; the air then sinks back down and spreads out: Where the mesocyclone is located Behind the wall cloud is the tail cloud http://www.youtube.com/watch?v=cvOut9VUqKY&safety_mode=tru e&persist_safety_mode=1&safe=active Tornado capital of the world Perfect conditions for tornadoes due to the cold air from the Rocky Mountains clashing with the warm dry air from the Gulf of Mexico It is estimated that about 1,300 tornadoes are recorded in the United States every year Tornado season is from March to July Category EF0- light damage (confirmed tornadoes with no damage: empty fields) EF1- moderate damage EF2- considerable damage EF3- severe damage EF4- devastating damage EF5- incredible damage Wind Speed 65-85 mph 86-110 mph Characteristics Peels surface off roofs, damage to gutters and siding, shallow rooted trees pushed over Roofs severely stripped, mobile homes destroyed, windows and glass broken 111-135 mph Roofs torn off framed houses, foundations shifted, large trees snapped or uprooted, car lifted off ground, light objects turned into missiles 136-165 mph Entire stories of houses destroyed, damage to large buildings, trains overturned, trees debarked, heavy cars thrown, weak structures blown away 166-200 mph Well constructed homes completely leveled, cars thrown, small objects become missiles 200 + mph Nothing left EF5 tornadoes have wind speeds so powerful it can make really odd things happen Grass blades become missiles and have been found in the big thick wooden telephone polls A full size chicken has been found crammed in a glass bottle Hail forms when supercooled water is swept up and freezes, sometimes it falls, then is swept up again and refreezes and so on It grows larger with each cycle of freezing over and over again They remain in the cycle until they are too heavy and fall to the Earth Large hail usually occurs in supercells Some can produce hailstones as big as softballs According to the National Weather Service, the largest hailstone is 8 inches in diameter and weights approximately 2 pounds. It fell in Vivian, South Dakota on July 23, 2010. It is nearly impossible for meteorologists to get wind measurements at ground level of tornadoes because they obliterate everything in their path Tim Samaras and his team TWISTEX created an armor-plated probe which was designed to have the tornado move over the probe and record measurements He has to put the probe down in the path of the tornado His probe was the first to film the inside of the tornado http://video.nationalgeographic.com/video/environment/environmentnatural-disasters/tornadoes/tornado-samaras/ http://www.youtube.com/watch?feature=player_detailpage&v=-nKGOjNh_lI#t=79s http://www.youtube.com/watch?v=56nh_Awr7po&safety_mode=true&persist_safety_mode=1 &safe=active Lightning Lightning occurs due to electrical charges separating in a thundercloud; the positive charges build in the upper region of the storm while the negative charges build in the lower region Cloud-to-ground: if the positive charge is on earth (like a tree) and the negative charges lightning goes from the clouds and strikes the ground Cloud-to-cloud: the most common type of lightning is within the clouds Lightning can raise the temperature of the air to as much as 50,000 degrees Fahrenheit (which is five times hotter than the surface of the sun) which in turn causes thunder http://www.youtube.com/watch?v=EyUsjsJ-E0c&safety_mode=true&persist_safety_mode=1&safe=active While most people think that tornadoes turn the sky green, that is FALSE!!! The sky actually turns green from water droplets scattering in the sky. It is a combination of the sky appearing red at sunset (that’s when most thunderstorms occur), and the blue sky Blue + red = green In 1959 William Rankin, a Navy pilot, was flying over Norfolk, Virginia when his engine shorted out, forcing him to eject while he was 9 miles (47,000 ft) above Earth, flying right over a supercell thunderstorm. As he descended into the storm, he was pelted by hail and slammed around by high winds “The first clap of thunder came as a deafening explosion….they were unbearable physical experiences…I didn’t just hear the thunder; I felt it.” “I saw lightning all around me…and I saw it in every shape imaginable….I had the distinct feeling I was being sliced in two” “I found myself looking down into a long, black tunnel” He was more than likely staring down into the interior of a tornado…it wasn’t something he could run away from, it was something he was falling into. He finally touched down on land in North Carolina 40 minutes later It was a descent that was suppose to be less than 10 minutes long DO have a tornado plan for your family household and DO practice it at least once a year DON’T go near windows DO pay attention to the warning signs If the weather channel or radio issues a Tornado Warning that means you need to get to safety immediately TOR: CON- a new system of warning people on TV, stand for tornado condition; the higher the number, the greater likely hood a tornado will be coming your way DO get to safety as fast as possible As cool as it may seem to try and see a tornado they are extremely dangerous and can be deadly If you have a basement in your house go to the basement or the lowest part of your house If there is no basement in your house go to a small, windowless room like a closet or bathroom (if in the bathroom crawl into the bathtub and cover yourself with a heavy blanket) DON’T open your windows It is a common myth that opening your windows when a tornado is coming that it will equalize the pressure and your house won’t explode when actually opening the windows does nothing but waste time DO have a ten second getaway plan DON’T go under an overpass If in the car DON’T try to outrun the tornado The winds that are squeezing under the overpass just make the winds even faster and stronger which puts you in even more danger Abandon the car and lie facedown in a ditch or any other lowlying area Tornadoes can travel from 30-70 mph on the ground DO be alert and know the signs of dangerous weather Pay attention for: rotating clouds, a storm that produces a sickly greenish color, large hail, a roar or rumble that doesn’t fade in a few seconds, leaves or debris getting sucked up into the sky, heavy flying debris Always remember four main things Get as low to the ground as possible Get behind as many walls as possible Stay away from windows Beware of flying debris, which represents the biggest danger http://www.youtube.com/watch?v=DFFE7WbgSew&feature=related&safety_mode=true&persist_safety_mode=1&safe=active http://video.nationalgeographic.com/video/environment/environment-natural-disasters/tornadoes/tornado-montage