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Understanding Tornado Fatalities

Understanding Tornado Fatalities. Churton Budd, RN, EMTP Toledo Area DMAT Center for Disaster Education & Research. What is a tornado?. A deadly weather phenomena A violently rotating column of wind extending to the ground from the base of a thunderstorm cloud.

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Understanding Tornado Fatalities

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  1. Understanding Tornado Fatalities Churton Budd, RN, EMTP Toledo Area DMAT Center for Disaster Education & Research

  2. What is a tornado? • A deadly weather phenomena • A violently rotating column of wind extending to the ground from the base of a thunderstorm cloud. • Wind speeds can vary from 72 mph to almost 300 mph, however only about one percent of tornadoes in the U.S. reach 200 mph wind speeds.

  3. A tornado's intensity is measured on the Fujita wind damage scale. • A measure of the strength of tornadoes and sometimes other wind storms, based on the potential to cause damage. The F-scale ranges from 0 through 5: • F-0: Light damage. Winds up to 72 mph. “Weak Tornado” • F-1: Moderate damage. Winds 73 to 112 mph. “Weak Tornado” • F-2: Considerable damage. Winds 113 to 157 mph. “Strong Tornado” • F-3: Severe damage. Winds 158 to 206 mph. “Strong Tornado” • F-4: Devastating damage. Winds 207 to 260 mph. “Violent Tornado” • F-5: Incredible damage. Winds above 261 mph. ”Violent Tornado” • One cant apply the F scale to any particular tornado for the entire damage path as the scale of the tornado may fluctuate

  4. Tornadoes have struck every state, including Alaska and Hawaii. However, most tornadoes form in a belt known as "Tornado Alley," from Nebraska south through central Texas. • Tornadoes account for almost half of all deaths attributed to weather-related disasters in the United States.

  5. FEMA & ARC: Suggested Safety rules • Don’t try to outrun the tornado in a car • If out in the open, or in a car get down in a low lying area. • If in a house, go to an inner room, basement, room without windows. Crouch down and protect your head. • Get under a sturdy piece of furniture, in the bathtub, under a mattress. • Avoid places with wide roof spans or long hallways. • Tom Schmidlin Report: Tornado Safety Msg. For Mobile home Dwellers - report based on study of two tornado’s • Ga / Al an F4, 3/27/94 & Ak F2-F4 3/1/97

  6. Lessons learned !!! • “Knowledge of the attributes of persons killed by tornadoes, their behavior when the storm threatened and the circumstances of their deaths are useful in evaluating hazard preparedness, safety rules and warning methods” - Thomas Schmidlin - Dept of Geography, Kent State University

  7. Schmidlin’s Report • In one of the Tornadoes seven people abandoned two mobile homes and got into a ditch. • Two men died when a tree fell on them. The other five people were unhurt • Damage indicated an F2 tornado • The two mobile homes were so destroyed their debris was never found • Some mobile homes may have been in lower intensity areas of the damage path

  8. Schmidlin’s Report • Traveled to the site of tornado disasters within one week of the strike and completed a detailed study of each fatality and survivor. • Method of warning, access to warning, time of awareness, location when storm struck, degree of destruction, etc.

  9. Survey’s were completed for 45 fatalities and 104 survivors • Both tornadoes struck rural areas in Southern states during weekend afternoons within 10-30 minutes warning time from the NWS

  10. Risk Factors for Death by Tornado • Advanced age • Located in a mobile home • Located in a room above ground, with windows • Not watching TV in the hour before strike • Being unaware of the tornadoes approach until one minute before strike

  11. Reinforced previous assumptions • Protection by a building • Mobile homes and outer rooms do not offer much protection • In spite of long warning times - most people became aware of the approaching tornado only when they saw or heard it - allowing little time to reach a shelter • TV was used more for weather info than NWS radio - nobody interviewed used it.

  12. Are cars safer than Mobile Homes? • Schmidlin’s study observed that many times, cars or pickups remained upright with little damage near mobile homes that were destroyed or the occupants killed. • Modern car has low center of gravity, protective interior, streamlined form designed for high winds, will protect occupants during a roll over and other crashes

  13. A door handle height of 120 mph is needed to overturn a car • 80 mph to turn over a mobile home

  14. Rural mobile home dwellers • Mobile homes are a liability with no inside rooms, no underground shelter, etc. • Drive to safety • Don’t go late, go early for shelter before the tornado is close and keep a wary eye when the weather is bad

  15. How safe is it to drive away in a car? • Schmidlin studied 180 cars within F1-F3 tornado areas • The % of cars moved or tipped increased with increase in damage to the home • For those cars in an F3 damage area • 1/2 were moved by the winds • 15 % were tipped • 39% of them had damage

  16. NWS Statistics • Out of 12,483 tornadoes • 84% were F0 & F1 • 11% were F2 • 3.5% were F3 • 1.5% were F4 & F5 • 503 fatalities • 7 were F0, 255 were F4 & F5 ( 5200 times greater chance of being killed in an F4/5 than in an F0)

  17. Jarrell, Texas - Case StudyTuesday 3:45 pm May 27th, 1997

  18. Cedar Park (Suburb of Austin) • 1 dead • 1/4 mile wide by 2 1/2 mile long • 100 homes and a shopping market destroyed • Hot and muggy Tuesday afternoon • Jarrell, T. Struck by F-5 • 28 people dead • 260 mph winds • 650 ft wide by 8 miles long was devastated Minor damage near the edge of the storm Jarrell, Tx.

  19. Weather / Preparatory Details • Hot and muggy - “Feels like Mexico” • Cloud tops were at 50,000 feet • Storms began in Bell County (to the north of Jarrell) and headed south into Williamson Co. • Funnel clouds began at 3:30pm • EMS units out of the county were called back, Off duty personnel called back in (Rigs staffed with 3-4 medics instead of 2). • EOC set up at Sheriff’s Dept.

  20. Where are all the Bathtubs? • “I’ve always been told that if you get in a bathtub to protect yourself from a tornado” - EMTP responding to Jarrell • The debris was so incredibly scattered it was in small pieces • Foundations wiped clean • “We were still expecting to find a dump somewhere where the storm let loose all of the material, but we have not found it”.

  21. Patient injury types in Jarrell, Tx • Green - 20 (8 treated and released on scene) • Yellow - 3 • Red - 1

  22. Search for bodies • After initial treatment, it was evident the remainder of the victims were fatalities • Arm to arm search to locate bodies and body parts • Rain continued - ankle deep mud • Most of the intact bodies were nude and disfigured, hair full of debris, body fluids literally centrifuged out

  23. Nearby • Cedar Park • Category F 3 • Supermarket roof caved in trapping 27 • one victim trapped under 12 feet of rubble (four hour extrication) Rescued by Central Tx. USAR.

  24. Was there a warning? • In Cedar Park, there was no National Weather Service Warning. (Still under watch!) • In Jarrell a siren was sounded 10 minutes prior to tornadoes touching down and many residents had seen or heard a tornado was coming • Those who heeded the warnings followed the standard procedures (shelter in bathtub, under mattress, etc. • Ironically, those who chose to flee survived - quite a few people in trailer homes got out and left! • “Had these people not done what they did, which was the wrong thing to do, they would be dead”

  25. The last word • For weak tornadoes (F0) there is little threat • For F1 - F3 • Underground shelter is best, interior rooms and houses provide life saving • Mobile homes are a HIGH risk • F4 & F5 • Deadly, with not much chance of survival above ground

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