The Fujita scale

Storm Data, Sept, 2004

The Fujita Scale

F-Scale     Intensity     Wind Speed      Typical Damage (Suggested)
                            (mph)

  F0      Gale Tornado      40-72      Tree branches broken, chimneys
                                       damaged, shallow-rooted trees
                                       pushed over; sign boards damaged
                                       or destroyed, outbuildings and
                                       sheds destroyed

  F1        Moderate        73-112     Roof surfaces peeled off, mobile
                                       homes pushed off foundations or
                                       overturned, moving autos pushed
                                       off the roads, garages may be
                                       destroyed.

                                       Category 1-2 hurricane wind
                                       speed

  F2       Significant     113-157     Roofs blown off frame houses;
                                       mobile homes rolled and/or des-
                                       troyed, train boxcars pushed
                                       over; large trees snapped or
                                       uprooted; airborn debris can
                                       cause damage.

                                       Category 3-4 hurricane wind
                                       speed

  F3         Severe        158-206     Roofs and walls torn off well
                                       constructed houses; trains over-
                                       turned; large trees uprooted,
                                       can knock down entire forest of
                                       trees.

                                       Category 5 hurricane wind speed

  F4       Devastating     207-260     Well-constructed frame houses
                                       leveled; structures with weak
                                       foundations blown off some dis-
                                       tance; automobiles thrown, large
                                       airborn objects can cause signi-
                                       ficant damage.

  F5       Incredible      261-318     Brick, stone and cinderblock
                                       buildings destroyed, most debris
                                       is carried away by tornadic
                                       winds, large and heavy objects
                                       can be hurled in excess of 100
                                       meters, trees debarked, asphalt
                                       peeled off of roads, steel
                                       reinforced concrete structures
                                       badly damaged.

  F6      Inconceivable    319-379     These winds are very unlikely.
                                       The small area of damage they
                                       might produce would probably not
                                       be recognizable along with the
                                       damage produced by F4 and F5
                                       wind speeds that would surround
                                       the F6 winds.