Tornado scale       Speed       Damage          Description        
                    (mph)                                          
F0                                                                 
Gale tornado        40-72       Light           Some damage to     
                                                chimneys and       
                                                signs.  Branches   
                                                break off trees;   
                                                shallow-rooted     
                                                trees pushed       
                                                over.              
F1                                                                 
Moderate tornado    73-112      Moderate        The lower limit    
                                                (73 mph) is the    
                                                beginning of       
                                                hurricane wind     
                                                speed. Surfaces    
                                                are peeled off     
                                                roofs; mobile      
                                                homes pushed off   
                                                foundations or     
                                                overturned.        
                                                Moving autos are   
                                                pushed off the     
                                                roads.             
F2                                                                 
Significant                                                        
tornado                                                            
                    113-157     Considerable    Roofs are torn     
                                                off frame houses   
                                                and mobile homes   
                                                demolished.        
                                                Boxcars are        
                                                pushed over,       
                                                large trees are    
                                                snapped or         
                                                uprooted, and      
                                                light-object       
                                                missiles           
                                                generated          
F3                                                                 
Severe tornado                                                     
                    158-206     Severe          Roofs and some     
                                                walls are torn     
                                                off                
                                                well-constructed   
                                                houses; trains     
                                                are overturned.    
                                                Most trees in      
                                                forests are        
                                                uprooted, heavy    
                                                cars are lifted    
                                                off ground and     
                                                thrown.            
F4                                                                 
Devastating                                                        
tornado                                                            
                    207-260     Devastating     Well-constructed   
                                                houses are         
                                                leveled;           
                                                structures with    
                                                weak foundations   
                                                are blown off      
                                                and travel some    
                                                distance.  Cars    
                                                are thrown and     
                                                large missiles     
                                                generated.         
F5                                                                 
Incredible tornado  261-318     Incredible      Incredible         
                                                tornado (261-318   
                                                mph); incredible   
                                                damage. Strong frame                                                       
                                                houses are lifted                                                  
                                                off foundations                                                    
                                                and carried                                                        
                                                considerable                                                       
                                                distance to                                                        
                                                disintegrate.                                                      
                                                Automobile-sized                                                   
                                                missiles fly                                                       
                                                through the air                                                    
                                                in excess of 100                                                   
                                                meters. Trees are                                                           
                                                debarked. Incredible                   
                                                phenomena will                   
                                                occur.