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