HAROLD BROOKS NOAA/NSSL Tornado deaths: What the past tells us about the future

General History of Death >20000 people have died in US tornadoes (~400 years) Deadliest decade-1920s (95 min, 4 years>200, 3169 total)  : 419 deaths  : 558 deaths Only 3 years since 1974 > 100, max is 130 (1998)

10 Years of Tornado Fatalities by County 631 Total Fatalities Avg. Fatalities ~2.5 Avg. Injuries ~21 Avg. Prop. Dmg. ~$18M Avg. Track ~18 miles Avg. Width ~500 yards Avg. Rating ~(E)F2.5

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

Mobile Home Permanent Home

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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

Model Tornado Deaths (Brooks and Doswell 2001) Mobile home contribution to overall death rate

Mobile Home Permanent Home

Warning/response system 17 Warning  Decision  Dissemination  Reception Response  Preparation  Options  Action

Warning performance 18 Lead time?  Lead time for warned tornadoes hasn’t changed in 25 years

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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?

What are the issues? 22 Organization of storms (warning challenges) Ashley (2007) summarizes many aspects  Mobile homes  Nocturnal/visibility  Poverty Preparation/response

Nocturnal Tornado Death FractionMobile Home Fraction by County Forest CoverFraction in Poverty (Ashley 2007)

Compare to lightning 24 Which kills more in US?

Compare to lightning 26 Which kills more in US?  : Lightning (  =90), tornado (53), lightning more in 13 years  : 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

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