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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

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

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