ATM OCN (Meteorology) 100

TORNADOES & 
OTHER SMALL-SCALE VORTICES

Summer 2000

Lecture # 25 Scheduled for:

31 JUL 2000 (M)

Recommended Readings from Moran and Morgan (1997):

pages 323-335

Today's Lecture Objectives:

• To identify the typical characteristics and structure of a tornado.
• To locate the geographical areas in the United States having maximum annual tornado frequency and offer several reasons as to why these locations experience high tornado frequency.
• To explain why tornadoes are most frequent in spring.
• To describe the synoptic conditions necessary for tornado formation.
• To describe the linkage between thunderstorms and tornadoes.
• To explain in simple terms the concept of the conservation of angular momentum.
• To identify the causes of the destruction associated with tornadoes.
• To identify the Fujita Intensity Scale.
• To identify some weather phenomena that resemble funnel clouds.
• To discuss the role of  Doppler radar in monitoring small-scale circulation systems.
• To differentiate between tornado watches and tornado warnings and know the proper precautions to exercise for each.

Outline:

A. INTRODUCTION

• Definitions
• The Human Factor - Infamous Tornadoes
• Aliases, Myths, Misconceptions and Confusion

B. TORNADO MORPHOLOGY

• Fujita Intensity Scale
• Spatial Characteristics
• Types of Tornadoes
• The Mesocyclone -- Anatomy of a Tornadic Thunderstorm
• Tornado Families
• Supercells
• Tornado Life Cycle

C. TORNADO CLIMATOLOGY

• Geographic Distribution
• Seasonal Distribution
• Time of Day
• Long Term Temporal Trends

D. TORNADO THEORY

• Conditions Conducive For Tornado Outbreaks
• Synoptic Weather Factors
• Other Factors
• Dynamic Considerations
• Forcing Mechanisms
• Equation of Motion
• Conservation of Angular Momentum

E. TORNADO PUBLIC SAFETY

• Causes of Tornado Damage
• Tornado Detection
• Tornado Forecasting and Information Dissemination
• Tornado Safety Rules - Minimizing Tornado Damage

F. OTHER SMALL SCALE VORTICES

• Funnel Clouds
• Definitions
• Climatology
• Waterspouts
• Types of Waterspouts
• Climatology
• Dust Devils

Links to Other References:

• For Educational Resources
• Tornado lesson in The Severe Weather Information Kit (SWIK) from Univ. of Nebraska at Lincoln
• Tornado Exhibit from UCAR
• Links to Other Tornado and Severe Weather Sites
• The Thunderstorm & severe storm module from Weather World 2010 (Univ. of Illinois-Urbana-Champaign).
• Maps of 1950-1005 Long-Term Averages By State (from NCDC)

Last revision 6 June 2000