A.   Stages of Development

1. cumulus -- updrafts
   • towering cumulus
2. mature -- updrafts and downdrafts
   • time lapse
3. dissipating -- downdrafts

1. contrast between cold-warm and/or wet-dry
   • dryline
2. microburst winds and gust fronts
   • gust front = dust storm... PHX, July 11: Pic 1, Pic 2 ... time-lapse
   • virga
3. "severe" thunderstorm
4. hail ... lethal?
5. "supercell" -- time lapse
   • overshooting top
6. Mesoscale Convective Complex (MCC)
   • ...over Arizona

1. world = equator
2. U.S. = Florida (hail map)

1. lightning >> shockwave >> thunder
   
   • process: stepped leader ... return stroke
   • close call ... super slow motion
   • types: CG, CC, IC, and "bolt from the blue"
2. "sheet", "heat", and "dry" lightning (more)
3. lightning distribution map
4. lightning safety: Public Svc Ad
   • STAY AWAY FROM TREES!
   • warning signs!
5. fulgurite (from Queen Creek)
6. upper atmosphere lightning: sprites and blue jets

A.   Terminology and Concepts

1. mesocyclone
2. extreme low pressure vortex... video
3. form in SW quadrant of thunderstorm
   • tornado power ... vs. house ... vs. train
4. funnel cloud ... second example
5. wall cloud ... another ... and another
6. tornado family ... and here
7. Enhanced Fujita Scale (EF0-EF5) ... (original)
8. photogrammetry
9. Doppler Radar - hook echo
10. waterspout (#2) ... dust devils

C.   Distribution and Statistics

1. 75% of world's tornadoes are in the U.S.
2. seasonally - late afternoon in May ... animated map
3. geographically - "Tornado Alley"
4. annual average by state
5. trend: total number of tornadoes
6. trend: number of F3-F5 tornadoes
7. April 27, 2011

STORMS CHAPTERS ----->

Air Mass / Fronts

Midlatitude Cyclone

Thunderstorms

Hurricanes