2. HOW ARE THUNDERSTORMS MADE? Science Lab 2-10-11

3. What is a Thunderstorm? A thunderstorm is a storm with lightning and thunder. Its produced by a cumulonimbus cloud, usually producing gusty winds, heavy rain and sometimes hail.

4. How is a Thunderstorm made? The basic ingredients used to make a thunderstorm are moisture, unstable air and lift. You need moisture to form clouds and rain. You need unstable air that is relatively warm and can rise rapidly. Finally, you need lift. This can form from fronts, sea breezes or mountains.

5. Animation video on How THUNDERSTORMS Are Made http://www.youtube.com/watch?v=Nyzlt- dVgWQ http://www.youtube.com/watch?v=IatoWCinM9w Science Experiment: Making a thunderstorm in a test tube. Do not try this without an adult present and without proper safety equipment. (1 ½ minute clip.) 45 second animation video on how a thunderstorm is made.

6. When Are Thunderstorms most likely to occur? Thunderstorms can occur year-round and at all hours. But they are most likely to happen in the spring and summer months and during the afternoon and evening hours.

7. Interesting Fact… It is estimated that there are around 1,800 thunderstorms that occur across our planet every day. http:// www.weatherwizkids.com/weather-thunderstorms.htm

8. Make A Thunderstorm MATERIALS: clear, plastic container (size of shoebox) red food coloring ice cubes made with blue food coloring PROCESS: Fill the plastic container two-thirds full with lukewarm water Let the water sit for one minute. Place a blue ice cube at one end of the plastic container. Add three drops of red food coloring to the water at the other end of the plastic container. Watch what happens.

9. What Happens: The blue and cold water sinks while the red and warm water rises. This happens because of convection. The blue water represents the cold air mass and the red water represents the warm, unstable air mass. A thunderstorm is caused by unstable air and convection plays an important part. A body of warm air is forced to rise by an approaching cold front therefore thunderstorm’s form.

10. Vocabulary: Convection: the movement of air, usually upward Cumulonimbus cloud: A dark cloud charged with electricity; seen in thunderstorms. Dictionary.com