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Fujita Tornado Scale
F-0: 40-72 mph - GALE TORNADO - Some damage to chimneys, breaks branches, pushes over shallow-rooted
trees, damages sign boards.
F-1: 73-112 mph - MODERATE TORNADO - The lower limit is the beginning of hurricane force winds, peels
surface off roads, mobile homes pushed off foundations or
turned over, moving autos pushed off roads.
F-2: 113-157 mph - SIGNIFICANT TORNADO - Roofs torn off frame homes, mobile homes demolished,
boxcars pushed over, large trees snapped or up-rooted,
light-object missiles generated.
F-3: 158-206 mph - SEVERE TORNADO - Roofs and walls torn off well constructed houses,
trains overturned, most trees in forest up-rooted, heavy cars lifted
off the ground and thrown.
F-4: 207-260 mph - DEVASTATING TORNADO - Well constructed houses leveled, structures with weak
foundations blown off some distance, cars thrown,
large missiles generated.
F-5: 261-318 mph - INCREDIBLE TORNADO - Strong frame houses lifted off of foundations and carried
considerable distance to disintegrate, automobile sized
missiles fly through the air in excess of 100 meters, trees
debarked, incredible phenomena will occur.
F-6: 319+ mph - The MAXIMUM winds of tornadoes are not expected to reach the F-6 level
Descriptive Terms For Hail
1/8" Graupel (not true hail, also called snow pellets)
1/4" Pea
1/2" Mothball
3/4" Dime
7/8" Nickel
1" Quarter
1-1/4" Half dollar
1-1/2" Ping-Pong Ball / Walnut
1-3/4" Golf Ball
2" Hens Egg
2-1/2" Tennis Ball
3" Tea Cup
4" Grapefruit
4-1/2" Soft Ball
NOTE: The NWS would prefer that hail size be reported by actual measured size. Reports should give the
maximum dimension of the largest stone found. If there is very large variation in size, indicate the
largest found and the typical size.
Modified Beaufort Scale of Wind Effects
<1 mph Calm, smoke rises vertically.
1-3 mph Weather vanes stationary, smoke shows wind direction.
4-7 mph Wind felt on face, leaves rustle, wind vane begins to move.
8-12 mph Leaves and small twigs in motion, wind extends a light flag.
13-18 mph Wind raises dust and loose papers, small branches move.
19-24 mph Small trees with leaves begin to sway, crested wavelets on inland waters.
25-31 mph Large branches move, wires whistle, umbrella becomes difficult to control.
32-38 mph Whole trees sway, resistance felt walking into the wind, trash cans blown away.
39-46 mph Twigs break off trees, cars may veer off road.
47-54 mph Slight structural damagemay occur (shingles blown away), tall grasses laid flat by wind.
55-63 mph Shallow rooted trees blown over, difficult to breathe facing into wind.
64-72 mph Breaks branches off trees, damages signs, some windows blown out.
73-112 mph and Above See Fujita Tornado Scale above.
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