Tornado Intensity and Safety

Tornado Intensity Scale: Fujita Scale

• damages to structures and trees as an estimate of wind speed close to the ground

• F0 to F5

• not very accurate because it doesn’t consider things like construction style, age of home, etc., which influence damage

Tornado Intensity Scale: Enhanced Fujita Scale

• accepted in 2007

• extensive study to define more criteria for wind damage

• uses 28 types of structures and trees

  • each evaluated based on 9 levels of damage

  • EF0-EF5

    • corresponds roughly with the Fujita Scale so that historical records can be compared to modern events

Tornado Fatalities vs EF Scale in 2011

• 1706 total tornadoes in the US in 2011

• 6 EF5 tornadoes were 51% fatalities

Tornado Safety

• if indoors:

  • get below ground (basement or storm cellar)

  • if no basement, move to interior room with no windows

  • get out of mobile homes

• if outdoors on foot:

  • get in a ditch or hole

• if in a car:

  • drive away from a tornado on best road perpendicular to (right or left of) translation direction of tornado

  • don’t hide under highway bridge or overpass

• declining numbers of tornado deaths in recent decades

• better forecasting/warnings

  • tornado watch: favorable conditions for tornadoes; few hours warning (be prepared and stay near the radio)

  • tornado warning: take shelter