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

ATM OCN 100 Summer Satellite Image

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

ATM OCN 100 Summer

5 The Fujita Tornado Intensity Scale

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

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

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

ATM OCN 100 Summer DISTINGUISHING CHARACTERISTICS of TORNADO

ATM OCN 100 Summer 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

ATM OCN 100 Summer 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

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

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

ATM OCN 100 Summer 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

ATM OCN 100 Summer 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.

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

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

ATM OCN 100 Summer High Resolution Satellite Image

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

ATM OCN 100 Summer Landsat-7 Image of NW Wisconsin nr Siren 18 May 2001 (Pre tornado)

ATM OCN 100 Summer Landsat-7 Image of NW Wisconsin nr Siren 19 June 2001 (After tornado)