1. Severe Weather

2. Thunderstorms * a small intense weather system
* formed along cold fronts
* warm moist unstable air near the earth’s surface rises (convection)
* form cumulonimbus clouds
* clouds can reach 40,000 feet tall!

3. Severe Thunderstorms

5. Doppler Radar

6. Lightning

7. Lightning
* an electric discharge that occurs between positive and negative charges
* lightning can happen between clouds or clouds and the earth
* lightning causes the air to expand and contract rapidly to create thunder
* lightning can be 33,000*C that’s hot!
*lightning kills more people than other storms …Florida and Africa have the most strikes!

9. Hurricanes

10. Hurricanes * Tropical weather system Low pressure
* winds at least 120 km/hr
* form over warm ocean water
* called typhoon in the Pacific ocean
* called Hurricane in the Atlantic Ocean
* called Cyclone in the Indian Ocean
* formed by thunderstorms over warm tropical waters …winds traveling in different directions meet and cause spin

16. Tracking Hurricanes

17. Parts of a hunrricane

31. Tornadoes

32. Tornadoes * happen in only 1% of thunderstroms
* a small spinning cloud with high speed winds that are a low pressure
* forms from a funnel cloud poking out the bottom of a cumulonimbus cloud along a cold front where it collides with warm moist air
* 75% of the worlds tornadoes occur in the United States

54. Tornado Alley

55. Waterspouts

59. Weather Station Symbols