SEVERE THUNDERSTORMS
ORDINARY (“AIR MASS”) THUNDERSTORM LIFE CYCLE
SEVERE THUNDERSTORM
SHELF CLOUD
ROLL CLOUD
SQUALL LINE THUNDERSTORM
SQUALL LINE
MESOSCALE CONVECTIVE COMPLEX
Derecho 1) Concentrated area of convectively induced wind damage/gusts greater than 50 knots (60 miles per hour) 2) The area must have a major axis length of 400 kilometers. 3) Wind reports should show a continuous and nonrandom pattern of occurrence. For instance, a swath of storms should consistently produce wind reports as the system moves to the east or southeast. 4) In the storm reported areas, at least three reports, separated by 64 km or more, should include wind gusts greater than 64 knots, or 74 mph. 5) Derechos are typically continuous and can sustain itself for hours. With that said, no more than three hours can elapse between successive wind damage eve
DRYLINE
(Eagleman, 206) cP cT mT
(Eagleman, 209)
THUNDERSTORM DAYS PER YEAR
HAIL DAYS PER YEAR
TORNADO!
VERTICAL WIND SHEAR AND VORTEX TUBE
TORNADIC THUNDERSTORM CHARACTERISTICS
Conservation of Angular Momentum angular momentum=mass x velocity x radius
April 3-4, 1974 Super Outbreak
# TORNADOES BY STATE PER YEAR (# TORNADOES PER 10,000 SQ. MILES PER YEAR) “Tornado Alley”
U.S. TORNADOES BY MONTH
JET STREAM AND TORNADO ACTIVITY Winter Jet Spring/Fall Jet Summer Jet
FUJITA TORNADO SCALE
ENHANCED FUJITA TORNADO SCALE
Sharknado