IntroIntro Objective 03/7/2013 Describe how lightning forms. If you did not initial your name on the Missing Assignments sheet yesterday, do so today! Weekly WS #26: What are some characteristics of a severe thunderstorm? THUNDERSTORMS Thunderstorms Thunderstorm Brief, heavy storm consisting of: Rain Strong winds Lightning Thunder Thunderstorms Where do they form? Usually along cold fronts Anywhere atmosphere is unstable Rapidly rising warm air mixing with cold air Thunderstorms Formation 1. Warm air mass rises; surrounding air is cooler 2. Water vapor condenses; forms cumulus clouds 3. More energy and instability produce large, dark cumulonimbus clouds Thunderstorms Lightning Electric discharge that takes place between two oppositely charged surfaces Between cloud and ground Between two clouds Between two parts of the same cloud. Thunderstorms Lightning Formation Drawing Thunderstorms Thunder Rapidly expanding air from a lightning strike creates sound waves Thunderstorms Severe Thunderstorms Can produce one or more of the following conditions: High winds Hail Flash floods Tornadoes Thunderstorms Thunderstorm Safety Lightning is the most dangerous and it is attracted to tall objects Stay away from: Trees Bodies of water In an open area? crouch down Lightning Strikes Video Roy Sullivan Roy Sullivan biography Roy Cleveland Sullivan was a Forest Ranger in Virginia who had an incredible attraction to lightning... or rather it had an attraction to him. Over his 36-year career as a ranger, Sullivan was struck by lightning seven times - and survived each jolt, but not unscathed. His seventh strike put him in the Guinness Book of World Records. Lightning strikes: In 1942, the first lightning strike shot through Sullivan's leg and knocked his big toenail off. In 1969, a second strike burned off his eyebrows and knocked him unconscious. In 1970, another strike left his shoulder seared. In 1972 his hair was set on fire and Roy had to dump a bucket of water over his head to cool off. On August 7, 1973, another bolt ripped through his hat and hit him on the head, set his hair on fire again, threw him out of his truck and knocked his left shoe off. On June 5, 1976, a sixth strike in 1976 left him with an injured ankle. On June 25th, 1977, the last lightning bolt to hit Roy Sullivan sent him to the hospital with chest and stomach burns. Objective 03/7/2013 OutroOutro Describe how lightning forms. What are your chances of getting struck by lightning 7 times in your life? 1 in 16,000,000,000,000,000,000,000,000