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HAROLD BROOKS NOAA/NSSL HAROLD.BROOKS@NOAA.GOV Tornado deaths: What the past tells us about the future
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harold.brooks@noaa.gov General History of Death >20000 people have died in US tornadoes (~400 years) Deadliest decade-1920s (95 min, 4 years>200, 3169 total) 1986-1995: 419 deaths 2000-2009: 558 deaths Only 3 years since 1974 > 100, max is 130 (1998)
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10 Years of Tornado Fatalities by County 631 Total Fatalities 1999-2008 Avg. Fatalities ~2.5 Avg. Injuries ~21 Avg. Prop. Dmg. ~$18M Avg. Track ~18 miles Avg. Width ~500 yards Avg. Rating ~(E)F2.5
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harold.brooks@noaa.gov What happened in 1925? 8 Seminal weather events that changed society 1888 Blizzard 1900 Galveston Hurricane 1927 Mississippi River flood 1930s Dust Bowl 1925 Tri-State tornado
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Mobile Home Permanent Home
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harold.brooks@noaa.gov
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harold.brooks@noaa.gov Brooks and Doswell (2001) 14 Highlight role of education in reducing 3 May 1999 deaths Question whether downward trend (post-1925) stopped Model death rate as function of mobile home fraction
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Model Tornado Deaths (Brooks and Doswell 2001) Mobile home contribution to overall death rate
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Mobile Home Permanent Home
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harold.brooks@noaa.gov Warning/response system 17 Warning Decision Dissemination Reception Response Preparation Options Action
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harold.brooks@noaa.gov Warning performance 18 Lead time? Lead time for warned tornadoes hasn’t changed in 25 years
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harold.brooks@noaa.gov Warning performance 21 Lead time? Lead time for warned tornadoes hasn’t changed in 25 years POD has increased Sutter and Simmons-decrease in fatalities up to 15 minutes Hoekstra Preferred mean lead time 34 minutes Given 1 hour lead time, respondents less likely to act immediately, more likely to flee Stalker-Long lead-people prepared to take action False alarms? Many convolved factors (SE primarily) What do people think is a warning for them?
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harold.brooks@noaa.gov What are the issues? 22 Organization of storms (warning challenges) Ashley (2007) summarizes many aspects Mobile homes Nocturnal/visibility Poverty Preparation/response
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Nocturnal Tornado Death FractionMobile Home Fraction by County Forest CoverFraction in Poverty (Ashley 2007)
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harold.brooks@noaa.gov Compare to lightning 24 Which kills more in US?
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harold.brooks@noaa.gov Compare to lightning 26 Which kills more in US? 1976-90: Lightning ( =90), tornado (53), lightning more in 13 years 1996-2010: Lightning (41), tornado (63), lightning more in 3 years Lightning deaths dropped dramatically starting ~1990 Education-“30-30 rule” Training-ER docs less likely to kill you now than 25 years ago
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harold.brooks@noaa.gov Final thoughts 27 Reducing deaths won’t come by improving forecast quality (lead time, POD, FAR) Non-meteorological problem Education/preparation Choices for appropriate action Communication of messages
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