Ultimate Tornado

Wow tornadoes are unpredictable and lethal they destroy towns there were no houses left they were all gone and bewilder scientists it's not an exact science every tornado is unique most are dangerous and a few are deadly this is a countdown to the ultimate disaster a super tornado that experts believe will someday devastate a major city when an ominous darkness fills the sky what tornado could be on its way these clouds are precursors to a powerful storm a supercell most tornadoes form when a turbulent column of air stretches down from that supercell to touch the earth in general the faster the wind speeds the more dangerous the tornado surprisingly relatively little is known about these giant killers scientists are literally chasing the mysteries of tornadoes across the great plains of the United States better known as Tornado Alley more than four hundred tornadoes threatened to create a path of destruction here every year far more than any other place in the world the main reason ideal atmospheric conditions the mountains to the west the Gulf of Mexico to the south and the fact that there are no physical barriers between here and the North Pole means that we are frequently changing air masses from warm to cold and back again tornadoes are measured using the F scale F is for dr. Theodore Fujita who classified tornado strength by estimating wind speed based on devastation the tornadoes we'll explore here ascend up the Fujita scale from an f2 that rips the roof off a house - an f5 that lays waste to an entire neighborhood all leading up to a super tornado one that some scientists fear will ravage a major city 69 miles southwest of Wichita lies the small town of Attica Kansas just over 600 people live here it's a town you could easily miss but on May 12 2004 a tornado didn't on that day the blue skies over Harper County filled with storm clouds shortly after 6 p.m. Dan Smith Heisler heads into Attica I did some work for the banker in there and I told his wife I said you know it's gonna storm today several thunderstorms form over southern Kansas 1 look at these storms tells 30-year veteran meteorologist chuck DAWs well they might be a breeding ground for tornadoes one of the important ingredients that produces a tornado that we're pretty sure is the wind at low levels has to change direction and speed rapidly with height we call that vertical wind shear vertical wind shear spins the air into an invisible cylinder as the wind rises and the speed increases the tornado intensifies and the core pressure drops condensation from the dropping pressure builds down the funnel creating a visible tornado that's exactly what's happening in this southern Kansas sky Harper County Emergency Management Director Mike Lord gets the first tornado warning at 6:45 and when they start giving us those warnings we listen and we say hey we need to start warning our public from there we do not know if this is going to be an f0 or it's going to turn into the monster in Kansas meteorologist carefully follow the storm as it tracks towards Attica about 7:25 in the evening a f2 tornado and made it to ground right up here just on this hill the path of it was right across here as Laurie watches in astonishment the tornado tears the roof off a home directly in front of him Oh unfortunately the skies over Kansas are just beginning to brew up weather that will soon devastate the area we thought okay hopefully things are over we got emergency crews set up for that and then it distorted suddenly it took a life on its own storm chasers tracking the Kansas supercell relay information to meteorologists using mobile to radar they report the tornados wind speed location and one other startling fact the storm is producing multiple tornadoes it can be a very dangerous situation because often people will be looking at the main tornado and feeling that as long as they're far enough away or there they've taken cover that that they should be completely safe her team and others report seeing 16 tornadoes they vary significantly in size and power the biggest is an f4 roughly 100 miles per hour faster and with corresponding wind force about three times larger than an f2 the f4 heads straight for Dan and Donna Smith hi slurs home chard here mr. pappan noise or we have rakha Canada and those contra popping from the the pressure change it sound like popcorn we're going off over there the tornado batters Dan and Donna with winds estimated at more than 200 miles per hour and that's when I got hit on my head with see me and or something you know I can still hear myself groan you're just gonna let go with it and that's where I was when he said we're not gonna make it and that woke me up and I said oh yes we are too you know and you pray really hard the savage winds tear relentlessly through the Smith high slurs home when they finally stop the couple emerges from their basement into a war zone and I thought where's the car and my next thought was where's the garage the twister destroyed the couple's two-story home five barns dismantled five cars and killed their dog sugar the terror down there was the worst part the terror the Smith hi slurs are lucky to be alive with estimated wind speeds near two hundred and fifty miles per hour the f4 tornado easily destroyed their home but even the earlier f2 with winds estimated at a hundred fifty miles per hour was capable of ripping the roof off their house complex physics transform air into a lethal force a concept scientists are trying to understand what we're trying to do is simulate the tornado as best as we can so we're actually comparing the wind which we generate here with with the measurements made in the field and the match is pretty good dr. Parviz our car's tornado simulator is the first of its kind in the world it uses dry ice to create a visual display of the wind inside a vortex his machine can produce tornadoes up to four feet in diameter and eight feet tall with peak wind speeds of 55 miles per hour when used with scale models he's able to replicate the damage that larger and faster tornadoes inflict on homes and other structures normally our portion of the roof fails and create a hole in the building which then the flow starts getting inside which then creates more load on the on the walls and eventually those walls start failing Sarkar's experiments conclude that the destructive force of circulating wind in an f3 or stronger tornado is at least three times more powerful than straight-line winds since few structures in tornado alley are designed to withstand f1 winds this is stark proof that even the weakest tornado is capable of causing severe damage the residents of Attica were thankful to have survived the fury of the 16 tornadoes that struck southern Kansas a unique and dangerous f4 twister is poised to devastate a small Texas town and later what if a mega tornado strikes a major American city experts say it will happen when we return in 2004 a single Kansas storm produced a group of tornadoes that ravaged homes destroyed property and terrorized hundreds but the power and damage of that outbreak was far surpassed by the stunning force and unpredictable behavior of a single Texas twister Pampa Texas has had its share of luck the town has prospered since oil was discovered here in 1921 today 17,000 residents work the hard soil farming ranching and refining oil but the town's location in the Texas Panhandle is also its biggest flaw this is Tornado country on the afternoon of June 8 1995 pampas luck ran out Randy Stubblefield is a lifelong resident of Pampa in his two years as sheriff he's seen his share of trouble but nothing compares to what he's about to confront about four o'clock in the afternoon we received a call that there was a large tornado was building on the south side of the Emerald Highway just about a mile and a half from where we're standing with Stubblefield grabs his camcorder and rushes towards the twister I watched it building on the farmland on the north side of the railroad tracks and it just started building getting bigger and bigger meteorologist Chuck Doswell is also chasing and filming the Pampa tornado the evolution of the Pampa tornado with respect to the parent thunderstorm was very unusual in my experience i've never seen anything quite like it what Doswell sees is remarkable the tornado is almost standing still then suddenly the tornado makes a sharp right turn this odd behavior stuns Doswell tornadoes move in a particular direction because they're tied to the storm that's producing them and the storm that's producing the moves in a particular direction because it's embedded in a wind field which is pushing it in that direction but the Pampa tornado isn't moving in the same direction as the storm after a series of sharp turns the twister loops almost 270 degrees around Doswell these erratic and unpredictable movements make this a very dangerous tornado let's go and I am completely mystified as to what was going on with that storm then it started traveling north everybody inside this is one big Sunday and hit a industrial complex Belinda Waldrop works in that complex with her father she isn't listening to the news I learned that there was a tornado outside the building when my dad came to the door of the office I was in and said Belinda there's a tornado on the ground west of us I'm curious I said can we look at it and he said oh no we don't need to look at it we need to get under some cover Belinda and her father died for shelter as the twister slams torta you could hear the tornado approaching it was like a gyrating wolf with just a turning that just got gradually more intense louder then I began to flicker as the pressure was building and then the lights went out when he first starts seeing the real debris the metal the group tops know that that's when it hit the first series of steel buildings in the industrial complex and then an explosion the vacuum just took me up off the floor and slammed me into numerous things and was pulling me backward like ragdoll you're going to see some vehicles going into the air transport trailers and truck combination now these units weigh probably twenty two thousand pounds empty these were sucked up and in the tornado and we're going round and round stubble field and Doswell are among the few to ever film a tornadoes snatching up three ton trucks this is a massively powerful twister one that has belinda Waldron trapped in its ferocious grip when I was in it everything's dark and I've just tried to keep my eyes closed to protect my eyes I kept talking to myself thinking well this is it it dropped me out here into the parking lot and just dropped me on my back and I could see the cloud and the tornado it looked like a white ghost just going up and taking off Belinda's encounter with the tornado is over but Randy's is just beginning one of my deputies gets on the air says watch out you're too close you know you're too close when the breeze starts coming in the car with you I had my windows down and in the trash from the circulation was coming into the car with me he was headed right straight from the sheriff's office in the downtown section well I had at that time about 65 prisoners in jail and you know we have a big strong building but this big stroke or later the twister strikes Pampa destroying or damaging 200 homes and 50 businesses most buildings in the industrial park are ripped off their foundations Belinda is badly injured and in shock of course I was just stunned and I really couldn't feel anything I felt like my legs were probably broken I couldn't get my bearings because there was no building there were no landmarks that I recognized at all and I was just taken back fearing the worst Belinda desperately searches for her father he was draped over a motor he looked dead on a sleeve he was limp and he wasn't moving emergency workers rushed Belinda and her father to the hospital both are in serious condition five other residents are also injured miraculously there are no deaths as the wounded begin their recuperation experts study Stubblefield and Dawes Wells remarkable footage the tumble of two or three ton pickup truck along the ground and then hoisted in the air this takes incredible wind speeds probably in excess of a 150 miles per hour Dave Llewellyn researches the strange and complex forces at work inside tornadoes in a tornado the wind is not just swirling around it's actually spiraling strongly inwards Llewellyn believes that once an object like a truck is airborne it can be slammed to the ground by powerful Center downdraft winds then hurled back skywards by updraft winds this brutal cycle renders the debris unrecognizable before it's finally shot out high-speed missile amazing that was 4,600 pounds for under the crane Scot Schiff and his team at Clemson University are studying what type of damage a car thrown from a tornado can do we're really testing there's a roof slab here and this was designed to be a shelter it's by tends to stick a solid concrete with a double mat of steel reinforcement so it's heavily reinforced and it's really designed to be able to take large debris impacts after multiple impacts the slab begins to crumble so after that last impact we now have a permanent deformation in the slab that rebar that's down and that bottom mat here started to heal under the load and we started to see some more concrete falling down below there to counter multiple impacts Schiff is designing a steel mesh net to catch loose debris if that works it will be a huge step forward in tornado protection we are safe during the event and right after the event despite the Pampa tornadoes unpredictable movements and incredible power no lives were taken 378 miles away another Texas town isn't so fortunate when a massive f5 twister turns bits of dirt and wood into lethal weapons the National Geographic Channel presents continues next it's one of the most destructive forces on the planet as powerful as 67 thousand atomic bombs scientists believe a major metropolitan area next target ultimate earthquake next on the National Geographic Channel would you know it one moment we're on the road you you you you you you you you you you you the Gerald twister killed 27 people and changed the way experts watch for potential tornado producing storms on May 3rd 1999 the people of Oklahoma City faced the worst f5 in modern history the Mather 1999 tornado they went through more in southern Oklahoma City was one of the most damaging in the history of the United States no matter how we look at the data late in the afternoon weather forecasters carefully tracked multiple supercell storms and the tornado reports that begin coming in at home with her eight-year-old son Dana Grimm watches the local news we had been watching the coverage for hours he said it just kept building momentum getting bigger and bigger and if you were above ground you weren't going to make it the storm system is intense complicated and growing weather trackers watch in shock as multiple storms produce multiple tornadoes seem like just about every thunderstorm cloud that formed eventually produced a tornado at some point and there were times when you had the main tornado happening and then we had what we call satellite tornadoes that would rotate around it there are completely separate tornadoes within the same storm system at about 625 a large tornado touches down just outside amber Oklahoma Doppler radar records it's wind speed at 318 miles per hour the fastest twister ever documented this is a monster and it's hurtling towards Dana Grimm's home and they had said that it was a mile wide and just ferocious and it was just destroying everything in its path with the giant wall of howling wind just a mile away Dana and her son hide in a closet I remember my son he was screaming and crying he said are we going to be okay if we're gonna be fine he said what do we do and I said we prayed dana's fear turns to panic when she hears the tornado strike there was kind of a high-pitched squeal to it and then of course the sound of everything the the windows blowing out the house was shaken we could hear there the beams in the roof breaking the walls just lifted up and we could feel really cold air rushing underneath and within seconds of that the house just blew up I couldn't breathe that I had sucked in so much dirt that I couldn't even breathe anymore I thought this is it and I remember just praying that God if this is it I'm ready the fierce tornado spares Dana's life by lifting her out of the suffocating dirt when it slams her back to the ground she's paralyzed with fear and I realized then that I didn't have my son so I started screaming for him and he came running over and it was really it was just a miracle of God because we were both barefoot he came running over to me did not have one puncture wound on his face the f5 continues toward the center of Oklahoma City crossing major highways filled with rush-hour traffic as the tornado races toward them some people panic they abandon their cars in a desperate attempt to find shelter or a few that decision has fatal consequences three people seeking refuge under freeway overpasses are killed by debris and the sheer force of the wind stranded cars block escape routes from many others shield Boulevard in Oklahoma City essentially became a huge parking lot and it blocked people from being able to escape the tornado by the time the f5 dissipates 40 people are dead and nearly 700 are injured my wife worked in the hospital in Norman that night and she worked in the emergency room and they were swamped of course she saw some really horrific injuries people came in covered with splinters of wood looked like pin cushions and so much wood awful things many survivors are injured by the wood and other debris spewed into the air as the tornado destroys home after home the Oklahoma twister leveled nearly 3,000 buildings 73 miles an hour Schiff and his team at Clemson University fired two-by-fours at 73 miles per hour into a variety of structures to approximate the damage done during a tornado I think that the public understands attorneys are very dangerous what they don't understand is that in typical construction they have very little protection against those types of events when debris Pierce's a home it does far more damage than simply making a hole in a wall or door that pole gives the fierce tornado winds a point of entry once inside they can blast through a wall or roof further fueling the tornado with more debris making it even more destructive this type of construction is very typical for a residential you know brick linear in front of a wood frame wall the missiles going all the way through the wall cavity most people that have this type of house would be vulnerable to an f5 tornado shift's experiments determined that for a home to withstand the deadly onslaught of debris the brick veneer must have a three-inch thick backing of concrete so this wall here to be suitable for a shelter to resist tornadoes most homes in Oklahoma City were brick veneer with wood frames this common construction coupled with the number of homes in the tornado's path increased the debris field exponentially Dana grim survived with a broken back her son with a puncture wound to his chest I truly believe that the reason that I was thrown twice if I had not been picked back up and thrown again I would have suffocated because I could not breathe in anymore 10 supercell storms spawned more than 70 tornadoes that spring day including the f5 that cut a 38 mile path over interstate highways and devastated several suburbs of Oklahoma City it was said I think there were 14 in our own housing edition that died and it it's a miracle of God that we didn't the Oklahoma tornado caused more than a billion dollars in damage making it the costliest tornado in US history things would have been much worse if the tornado had veered just ten miles to the west striking the heart of downtown Oklahoma City even so the Moore Oklahoma tornado and its companion twisters ranked as the most deadly and destructive outbreak in modern history but they would be far surpassed by an f5 striking a major American city and that would be a mega disaster and one that experts warned could happen when we return not every year major US cities in Tornado Alley play Russian roulette with massive twisters that develop there in 1999 Oklahoma City found itself in the path of a giant tornado that killed 40 people injured nearly 700 and racked up costs of more than a billion dollars it was only chance that kept the tornado from striking downtown researcher Scott ray knows the next major city to be struck by an f5 may not be so fortunate Dallas is overdue for a large violent class tornado Dallas Texas is a boomtown sprawled along the southern boundary of Tornado Alley it's one of the largest and fastest-growing metro areas in the US with more than five million residents and 600 corporate headquarters Scott ray assists local and state governments with planning for hazards especially threats from tornados to help Dallas prepare for the ultimate tornado he has prepared over 60 different scenarios of how the Dallas region would be affected by a violent twister for reasons of credibility it was very important that we look at an event that actually had occurred somewhere else so we took the the event at Oklahoma City basically because the data was very good for that particular event and we could transpose it by just moving those same geographical characteristics of the tornado on top of the geography of dallas-fort worth so we got to see it kind of from our own perspective ray and his team painstakingly overlay the exact path taken by the Oklahoma tornadoes over the dallas-fort Worth area the ultimate disaster unfolds when Oklahoma's f5 tornado rampages through downtown Dallas it would easily be the worst damaging tornado event that we have had to date in the US Ray's nightmare scenario begins as a supercell storm forms over northeastern Texas a 100 mile-per-hour tornado an f3 touches down in a dusty field 10 miles southwest of Dallas its first target is the suburb of cockerel hill now packing winds in excess of 200 miles per hour cars are tossed aside buildings are decimated the tornado continues northeast unrelenting in its assault on thousands of homes the twisters internal wind speeds rise past 250 miles per hour turning it into an f5 fueled by tons of debris the giant tornado slows as it descends on the busy freeway a clogged highway holds a heck of a lot more people than one that is moving comfortably and the other problem that you have is where do you go panic ensues as many abandon their cars creating a traffic jam that traps thousands the tornado strikes the 275 mile-per-hour winds effortlessly SWAT cars off the highway anyone unlucky enough to be hiding under an overpass is vulnerable to flying debris and violent winds cars snatched up by the powerful updrafts are spun around inside the giant vortex then shot out at speeds of up to 100 miles per hour next the deadly twister approaches downtown Dallas dozens of skyscrapers and tens of thousands of people crowd the city giant glass windows shattered marble and bricks are ripped off buildings a deadly shower of glass and stone rained down on the crowd below a packed commuter train snakes through the city its railway cars are swept off the tracks slamming into skyscrapers killing hundreds there's little doubt that debris would be probably the largest generator of damage in the Metroplex and it's basically because there's so much of it that can be generated and you name it it could be wood bricks gravel just about anything you can imagine can become a projectile and and with almost unlimited supply the tornado continues north leaving the wreckage of downtown Dallas behind with winds over 300 15 miles per hour it now descends on the suburban landscape of Lakewood the ninety two thousand people living here have had up to 20 minutes to seek underground shelter but like in the Jarrell twister those hiding in closets or bathrooms can only pray finally the worst tornado in history slowly drifts skyward and dissipates the trail of destruction it leaves behind is 30 miles long Dallas is devastated I don't think there's there's any way to really sugarcoat an event it's gonna be difficult to deal with regardless so there's gonna be a lot of damage there gonna be a lot of people that need help total damages top three billion dollars tens of thousands are homeless and scores injured the death toll is unknown the fatalities are difficult to really quantifies because they involve people making decisions and there are good decisions that can be made bad decisions we don't know a decision they're going to make the best decision city planners can make is to prepare with multiple underground shelters and rehearsed evacuation plans but even that probably won't be enough I think you would pretty much be impossible financially to build a city that can really survive violent class tornadoes or you know any scenario like that with increasing populations in major metropolitan cities throughout Tornado Alley science is in a race against time to understand one of mother nature's biggest secrets in an ideal world we'd have radar or other instrument measurements on every tornado that occurs in the practical world that we live in that's just not going to happen okay this storm in the next hour is gonna produce this type of tornado but we're just not there yet and it's hard to say when we'll be there we've certainly got a ways to go given the limited ability of science to predict tornadoes there is a very real cause for concern if you wait long enough something resembling the worst-case scenario is going to happen eventually and when it does hopefully science will have learned enough about these brutal forces of nature to provide us with the means to survive the ultimate tornado this is national