2. Journal W-5 There are two types of pressure systems that are related to weather. Name them and the type of weather associated with each.

3. There are basically 5 types of severe weather that form from low pressure systems that affect the United States –Thunderstorms –Tornados –Tropical storms –Hurricanes –Winter Storms

4. A. Thunderstorms 1. Found near cold fronts as cold air pushes warm moist air rapidly into the atmosphere. 2. Lifecycle (about 1 hour) a.Cumulus-15 minutes of strong winds moving up (updraft) b.Mature-30 minutes of heavy rain, strong wind, lightning, maybe hail c.Dissipating-15 minutes of downdrafts overtake updrafts and the storm loses energy http://www.youtube.com/watch?v=_c l0aw87LqA&feature=player_detailpa ge http://www.wiley.co m/college/strahler/04 71480533/animation s/ch06_animations/in dex.html

5. 3.Thunder and Lightning a. lightning is caused by the attraction of opposite charges inside a cloud or between the cloud and the ground. 1.Kills over ____ people per year 2.Hotter than the ________ 3.__________million strikes in US per year 4.______people struck in a year only ____survive 5._______occurring at any given moment on Earth 6.Ice particles build up. Large particles have a ____ charge and small particles have _____ charge. When they collide, lightning is formed 7.The result is a bolt of ______ amps 8.Travels 200 000 feet per second b. Thunder is caused by the rapid heating (up to 30000 0 C) of air around lightning-like a shock wave http://www.youtube.co m/watch?v=p-5Qra- Ms64&feature=player_ detailpage

6. 4. Supercell thunderstorms are much larger, more powerful, and last for several hours. Supercells may lead to the formation of tornadoes. http://www.youtube.com/wat ch?v=36vGiE5JQzs&feature =player_detailpage http://www.youtube.co m/watch?v=HaGdxy5er I0&feature=player_deta ilpage http://www.youtube.com/watch?v= Teis2gC- CLw&feature=player_detailpage

7. http://www.youtube.co m/watch?v=khLcpi2H ptM&feature=player_ detailpagehttp://www.youtube.co m/watch?v=khLcpi2H ptM&feature=player_ detailpage Orange-gust front Red-Storm Front Yellow-Advance Storm Pics http://www.youtube.com/watch?v= RqqCESro- rc&feature=player_detailpage http://www.youtube.com/watch?v= 37nsUIIMkeE&feature=player_det ailpage

8. Very cool stuff. BUT…. If the hair on your arm stands up GET LOW AND RUN!

9. B. Tornadoes-a violently rotating column of air 1.Arise from differences in air pressure called wind shear 2.Can only be seen because of the debris it picks up 3.Tornadoes are 400-500 feet wide. * 4.Tornadoes have winds around 100 miles per hour.* 5.Tornadoes last only a few minutes.* 6.Very destructive 7.Tornadoes occur most often in the spring (April- June) *Some are bigger and last longer-this is average

10. 8. About 1200 occur globally each year. 75% of all tornadoes occur in the United States along “Tornado Alley,” an area that runs from Texas to Illinois. http://www.youtube.com/watch?v=cvOut9VUqKY&feature= player_detailpage http://dsc.discovery.com/videos/won ders-of-weather-extreme- weather.html

11. 9. Tornado are categorized using the Fujita Scale or F-scale. It ranks tornadoes by their wind speed. Range is F0-F5. 85% are F0-F1 F0 (Gale) F1 (Weak) F2 (Strong) F3 (Severe) F4 (Devastating) F5 (Incredible) http://www.youtube.com/wat ch?v=jLrcXFoPbHI&feature =player_detailpage http://esminfo.prenhall.com/science /geoanimations/animations/Tornado es.html

13. C. Tropical Storm-a storm that forms from a low-pressure system(sometimes called tropical disturbances or depressions) with winds of 40-73 mph

14. D. Hurricanes-A tropical storm becomes a hurricane when its winds exceed 73 mph. They form over the Atlantic ocean 1. Other names a.Indian Ocean-called a typhoon b.Pacific Ocean-called a cyclone http://www.youtube.com/watch?v=HJydFJ ORWf4&feature=player_detailpagehttp://www.youtube.com/watch?v=HJydFJ ORWf4&feature=player_detailpage

15. 2. Hurricane Facts a.They can be 600 miles across. b.Hurricanes move very slowly and last for days c.Hurricanes have a spiral shape, like a pinwheel. The main body is called the eye wall with winds moving counter-clockwise. d.At the center of a hurricane is a calm area 20 to 30 miles wide called the eye. e.Hurricanes cause damage through: high winds, heavy rain, storm surge, and flooding. f.Hurricane season runs from June through November. g.They can be seen from space http://www.youtube.com/watch?feature=player_detailpage&v=eT5K6FR_eVs

16. Picture from the International Space Station

18. h.Because hurricanes seldom travel in straight paths, meteorologists predict several paths. i.Hurricanes usually lose power as they travel over land or cold water. j. Hurricanes destroy beaches, buildings, and vegetation. k. Hurricanes bring strong winds, heavy rain, storm surges, flooding, and tornadoes. **A storm surge is a large mass of ocean water that mounds up in the middle of the hurricane and then crashes inland causing flooding http://www.youtube.com/watch?v=mJbfGUylkR0&feature= player_detailpage

19. l. Hurricane Categories: The Saffir-Simpson Scale Category 1 -- Winds 74-95 mph Category 2 -- Winds 96-110 mph Category 3 -- Winds 111-130 mph Category 4 -- Winds 131-155 mph Category 5 -- Winds over 155 mph (these are VERY rare) http://www.youtube.com/watch?v=gVkMwo26smk&feature=player_detailpage http://www.youtube.com/watch?feature=player_detailpage&v=gd8WiiXNxho M. They start as low pressure systems over warm water. This is where their energy comes from.

20. Hurricane Isabel http://www.youtube.com/watch?v=uLJS0 KccI8U&feature=player_detailpage

21. E. Winter Storms a.Blizzard-A snow storm with wind gusts of 35 mph or more b.Lake Effect Storms-heavy snowfall near Great Lakes c.Ice Storms-rain falls onto already cold or freezing ground http://www.youtube.com/watch?fea ture=player_detailpage&v=5v2Lm DUzscM

22. Review 1.Which is larger, a hurricane or a tornado? 2.Which moves faster, a hurricane or a tornado? 3.Which lasts longer? 4.Where do hurricanes form? 5.Where do tornadoes form? 6.What do we call the area of the US that has a high occurrence of tornadoes? 7.How long do tornadoes last? 8.How long do hurricanes last? 9.Describe three common winter storms. 10.Explain the lifecycle of a thunderstorm. 11.What causes lightning and thunder? 12.What is a supercell? 13.How is a hurricane different from a tropical storm? 14.Name the scales used to classify a tornado and a hurricane.