Fig. C.O., p.397Seven people died in the Mossy Grove, Tennessee, tornado on November 12, 2002.

Fig. 15-1, p.398

This worldwide map shows the average density of annual lightning flashes per squarekilometer.

Fig. 15-2, p.398 Fig. 15-3, p.398

Fig. 15-4, p.399 Fig. 15-5, p.400

Fig. 15-6, p.400 Fig. 15-7, p.401

Fig. 15-8a, p.402

(a) A violent storm over Socorro, New Mexico, on October 5, 2004, unleashed hailstones, many larger than golfballs and some 7 centimeters in diameter

Fig. 15-8b, p.402

(b) Most cars caught out in the open suffered severe denting and broken indows. In some cases, hailstones went right through car roofs and fenders.

Fig. 15-9, p.402 Table 15-1, p.403

Fig. 15-10 F-1, p.403

Dr. Ted Fujita developed theF-scale for tornadoes

Fig. 15-10 F-2, p.403

Fig. 15-10 F-3, p.403 Fig. 15-10 F-4, p.403

Fig. 15-10 F-5, p.403 Table 15 -2a, p.404

Table 15-2b, p.404 Fig. 15-11, p.404

(a)Wind shear, with surface winds from the southeast, and winds from the west aloft.

(b) This slowly rotating vortex can be pulled up into a thunderstorm, which can result in a tornado.

Fig. 15-12, p.404

A slowly rotating wall cloud descends from the base of the main cloud bank, an ominous sign for production of a tornado near Norman, Oklahoma, on June 19, 1980.

Fig. 15-13, p.405

Mammatus clouds are a sign of the unstable weather that could lead to severe thunderstorms and potentially tornadoes. These formed over Tulsa, Oklahoma, on June 2, 1973.

Fig. 15-13a, p.405

These two tornadoes are associated with slowly rotating prominent wall clouds. In (a), a tornado descends from a wall cloud south of Dimitt, Texas, on June 2, 1995 Fig. 15-13b, p.405

(b), a tornado forms above this wall cloud and reaches the groundoutside the wall cloud near Lakeview, Texas, on April 19, 1977. Inboth photos, the storm is moving from left to right.

Fig. 15-15, p.405

A common situation for tornado development is the collision zone between two fronts, commonly in the hook or “bow echo” of a rainstorm. A pair of curved arrows indicates horizontal rotation of wind in the lower atmosphere.

Fig. 15-16, p.406

This series of fourteen photos was taken of the Fargo tornado on June 20, 1957. The times, in minutes, show that the funnel cloud descended in less than thirty seconds; the tornado then rapidly strengthened for the next minute. Just before thephoto at 29.6 minutes,the funnel sheared off beforestrengthening againinto a much wider funnel.This whole sequence tookonly ten minutes.

Fig. 15-17a, p.407A big tornado south of Dimmitt, Texas, onJune 2, 1995 Fig. 15-17b, p.407

Fig. 15-17c, p.407 Fig. 15-18, p.407

Fig. 15-18, p.407

This thin, ropelike tornado was photographed at Cordell, Oklahoma, on May 22, 1981, just before it broke up and dissipated.

Fig. 15-19, p.408

Fig. 15-20, p.408

The 1977 Birmingham,Alabama, tornado shows how selective thedamage of tornadoes can be. Fig. 15-21, p.409

Six 700-pound I-beams were pulled from an elementary school in Bossier City, Louisiana, and carried by a tornado along these paths. Other objects such as a divingboard and a car were also carried significant distances.

Fig. 15-22, p.409Ted Fujita hypothesized that many tornadoes were composed of multiple vorticesthat rotate around the Fig. 15-23, p.410

Fig. 15-24, p.410 Fig. 15-25, p.410

Fig. 15-26, p.411

May 3, 1999, tornadoes showstheir paths and intensities aroundOklahoma City.

Fig. 15-27, p.41

An Oklahoma tornado on May 4, 1999, threwthese cars into a crumpled heap.

Fig. 15-28, p.412 Table 15-3, p.413

Dryline Thunderstorms

• dryline•• These storms occur frequently in the southernThese storms occur frequently in the southernGreat Plains of the US. Great Plains of the US.

Fig. 10-35, p. 290

Severe Weather and Doppler Radar

• Doppler shift• tornado vortex signature• Doppler lidar• NEXRAD• waterspout

•• Many cities in the US have multiple Many cities in the US have multiple Doppler radars,Doppler radars,operated by television station weather operated by television station weather centers. centers.