Characteristics of Tornadoes
Tornadoes take many shapes and sizes, from thin and whispy to thick and massive. It may be helpful to think of tornadoes in three categories: weak, strong, and violent.
Weak Tornadoes:
- 69% of all tornadoes
- Less than 5% of all tornado deaths
- Lifetime 1-10+ minutes
- Winds less than 110 mph
- 29% of all tornadoes
- Nearly 30% of all tornado deaths
- May last 20 minutes or longer
- Winds 110-205 mph
- Only 2% of all tornadoes
- 70% of all tornado deaths
- Lifetime can exceed 1 hour
- Winds greater than 205 mph
There is another more accurate method of grouping tornadoes according to their strength. this method is known as the "F-scale" and is named after Dr. Ted Fujita who created it. It is used by meteorologists and storm chasers and is sometimes mentioned by television and radio weather reporters.
| F# | Wind Speed | Damage Severity | Description |
|---|---|---|---|
| F0 | 40-72 mph | LIGHT | Some branches off trees, damaged signs, some windows broken. |
| F1 | 73-112 mph | MODERATE | Peels surfaces off roofs, some trailers overturned, some trees snapped, outbuildings demolished. |
| F2 | 113-157 mph | CONSIDERABLE | Roofs torn off frame houses, mobile homes destroyed, and trees are snapped or uprooted. |
| F3 | 158-206 mph | SEVERE | Roofs and walls off well constructed homes, trains overturned, cars thrown, most trees uprooted. |
| F4 | 207-260 mph | DEVASTATING | Homes leveled, cars thrown, structures and large debris carried some distance. |
| F5 | 261-318 mph | INCREDIBLE | Strong homes cleaned to foundation, auto sized missiles, some engineered structures blown down. |