On May 20, 2013, a ferocious EF5 tornado over a mile wide tore through Moore, Oklahoma, inflicting 24 passings and obliterating entire neighborhoods. It was the third time an exceptionally unhappy tornado had struck the city in 14 years. Yet predicting when and where these hugger storms will hit still poses a huge challenge. Why was 2011-the worst ever recorded tornado season that left 158 dead in Joplin, Missouri-followed by the quietest ever year of activity prior to the Moore disaster? Can improved radar and warning technology explain why so many fewer died in Moore than in Joplin? And will tornadoes get worse as Earth's climate heats up? In this NOVA special, we meet scientists in the front ranks of the battle to understand these extreme weather events. We also meet storm survivors whose lives have been upended and learn how we can protect ourselves and our communities for the uncertain future.
 s40e01 - Secrets of the Viking Sword
        s40e01 - Secrets of the Viking Sword
          
        
      
     s40e02 - Forensics on Trial
        s40e02 - Forensics on Trial
          
        
      
     s40e03 - Mystery of Easter Island
        s40e03 - Mystery of Easter Island
          
        
      
     s40e04 - Ultimate Mars Challenge
        s40e04 - Ultimate Mars Challenge
          
        
      
     s40e05 - Inside the Megastorm
        s40e05 - Inside the Megastorm
          
        
      
     s40e06 - Doomsday Volcanoes
        s40e06 - Doomsday Volcanoes
          
        
      
     s40e07 - Decoding Neanderthals
        s40e07 - Decoding Neanderthals
          
        
      
     s40e08 - Rise of the Drones
        s40e08 - Rise of the Drones
          
        
      
     s40e09 - Who Killed Lindbergh's Baby?
        s40e09 - Who Killed Lindbergh's Baby?
          
        
      
     s40e10 - Building Pharaoh's Chariot
        s40e10 - Building Pharaoh's Chariot
          
        
      
     s40e11 - Earth From Space
        s40e11 - Earth From Space
          
        
      
     s40e12 - Mind of a Rampage Killer
        s40e12 - Mind of a Rampage Killer
          
        
      
     s40e13 - Meteor Strike
        s40e13 - Meteor Strike
          
        
      
     s40e14 - Ancient Computer
        s40e14 - Ancient Computer
          
        
      
     s40e15 - Australia's First 4 Billion Years - Awakening
        s40e15 - Australia's First 4 Billion Years - Awakening
          
        
      
     s40e16 - Australia's First 4 Billion Years - Life Explodes
        s40e16 - Australia's First 4 Billion Years - Life Explodes
          
        
      
     s40e17 - Australia's First 4 Billion Years - Monsters
        s40e17 - Australia's First 4 Billion Years - Monsters
          
        
      
     s40e18 - Australia's First 4 Billion Years - Strange Creatures
        s40e18 - Australia's First 4 Billion Years - Strange Creatures
          
        
      
     s40e19 - Manhunt - Boston Bombers
        s40e19 - Manhunt - Boston Bombers
          
        
      
     s40e20 - Oklahoma's Deadliest Tornadoes
        s40e20 - Oklahoma's Deadliest Tornadoes
          
        
      
    Seen in more than 100 countries, NOVA is the most watched science based television series in the world and the most watched documentary series on PBS. It is also one of television's most acclaimed series, having won many major television awards, most of them many times over.