1. ATM OCN 100 Summer 2002 1 ATM OCN 100 – Summer 2002 LECTURE 35 TORNADOES & OTHER SMALL SCALE VORTICES A. INTRODUCTION –What’s a tornado? –Definitions –Aliases, Myths, Misconceptions & Confusion

2. ATM OCN 100 Summer 2002 2 Satellite Image

3. ATM OCN 100 Summer 2002 3 A. INTRODUCTION (con’t.) u The Human Factor –Tornado Losses –Infamous Tornadoes u Intensity Rating –Fujita Intensity Scale

4. ATM OCN 100 Summer 2002 4

5. 5 The Fujita Tornado Intensity Scale

6. ATM OCN 100 Summer 2002 6 B. TORNADO MORPHOLOGY u Spatial Characteristics u Types of Tornadoes u The Mesocyclone u Tornado Families u Supercells u Tornado Life Cycle

7. ATM OCN 100 Summer 2002 7 B. TORNADO CLIMATOLOGY u Geographic Distribution u Seasonal Distribution u Time of Day u Long-term trends

8. ATM OCN 100 Summer 2002 8 Tornado Climatology See Fig. 14.4, Moran & Morgan (1997)

9. ATM OCN 100 Summer 2002 9 DISTINGUISHING CHARACTERISTICS of TORNADO

10. ATM OCN 100 Summer 2002 10 Anatomy of a Tornadic Thunderstorm  Warm, moist low level inflow from southeast  Vigorous rotating updraft with stretching and rotation u Overshooting top and anvil shape with strong upper level jet stream  Downdraft and gust front

11. ATM OCN 100 Summer 2002 11 D. TORNADO THEORY u Conditions Conducive For Tornado Outbreaks –Synoptic Weather Factors –Other Factors u Dynamic Considerations –Forcing Mechanisms –Equation of Motion –Conservation of Angular Momentum

12. ATM OCN 100 Summer 2002 12 E. TORNADO PUBLIC SAFETY u Causes of Tornado Damage u Tornado Detection u Tornado Forecasting & Information Dissemination u Tornado Safety Rules - Minimizing Tornado Damage

13. ATM OCN 100 Summer 2002 13 Causes of Tornado Damage u Strong Winds u Suction Vortices u Flying Debris

14. ATM OCN 100 Summer 2002 14 Tornado Detection u Eyewitnesses – Public, Public Safety Officials, Trained Spotters, SkyWarn u Storm chasers – VORTEX u Radar – Conventional Radar F Hook echoes – NEXRAD Doppler Radar F Tornado Vortex Signature (TVS) u Wind Profiler

15. ATM OCN 100 Summer 2002 15 NWS Watches & Warnings  Tornado watch –Issued by the National Weather Service to alert the public that conditions are favorable for the development of tornadoes.  Tornado warning –Issued by the National Weather Service to warn the public that a tornado has been sighted by storm spotters or has been indicated by radar.

16. ATM OCN 100 Summer 2002 16 F. OTHER VORTICES u Funnel Clouds –Definitions u Waterspouts –Types of waterspouts u Dust devils

17. ATM OCN 100 Summer 2002 17 High Resolution Satellite Image Siren Tornado June 2001

18. ATM OCN 100 Summer 2002 18 High Resolution Satellite Image

19. ATM OCN 100 Summer 2002 19 High Resolution Satellite Image Siren Tornado June 2001

20. ATM OCN 100 Summer 2002 20 Landsat-7 Image of NW Wisconsin nr Siren 18 May 2001 (Pre tornado) http://www.news.wisc.edu/newsphotos/siren.html

21. ATM OCN 100 Summer 2002 21 Landsat-7 Image of NW Wisconsin nr Siren 19 June 2001 (After tornado) http://www.news.wisc.edu/newsphotos/siren.html