Weather Phenomena

1. Weather Phenomena COS 12 Identify conditions that result in specific weather phenomena, including thunderstorms, tornadoes, and hurricanes. Identify cloud types associated with specific weather patterns Identify technology used to record and predict weather, including thermometers, barometers, rain gauges, anemometers, and satellites

2. Thunderstorms Thunderstorms, also called electrical storms or lightning storms, are a form of weather characterized by the presence of lightning and thunder produced from a cumulonimbus cloud. A shelf cloud associated with a heavy or severe thunderstorm over Enschede, The Netherlands.

3. In the mature stage of a thunderstorm, the warmed air continues to rise until it reaches even warmer air. Then is can not go any further. An anvil shaped thundercloud in the mature stage

4. Lightning is an electrical discharge that occurs in a thunderstorm. It can be seen in the form of a bright streak from the sky. Lightning occurs when a charge is built up within a cloud. When a large enough charge is built up, a large discharge will occur and can be seen as lightning. http://en.wikipedia.org/wiki/Thunderstorm

5. When a streak of lightning flashes across the sky, you often hear a crack of thunder several seconds later. http://en.wikipedia.org/wiki/Thunderstorm

6. We hear thunder because lightning heats the air to more than 43,000 degrees Fahrenheit, causing the air to quickly expand. The air then quickly cools after the flash, which causes it contract. http://en.wikipedia.org/wiki/Thunderstorm

7. This quick expansion and contraction of air around the lightning starts air molecules moving back and forth, making sound waves, which we hear as thunder. http://science.howstuffworks.com/enlarge-image.htm?terms=lightning&gallery=1&page=0

8. Tornadoes A tornado is a violently rotating column of air which is in contact with both a cumulonimbus cloud or, in rare cases, a cumulus cloud base and the surface of the earth. www.weatherpix.com/Tornadoes.jpg

9. Tornadoes come in many sizes but are typically in the form of a visible condensation funnel, whose narrow end touches the earth and is often encircled by a cloud of debris. http://www.hln-store.com/catalog/tornad.gif

10. The tornado itself is the thin tube reaching from the cloud to the ground. The lower part of this tornado is surrounded by a translucent dust cloud, kicked up by the tornado's strong winds at the surface. http://en.wikipedia.org/wiki/Tornado

11. Most tornadoes have wind speeds of 110 mph or less, are approximately 250 feet across, and travel a few miles before dissipating. http://www.ucar.edu/research/expeditions/images/tornadoes300.jpg

12. Hurricanes Hurricanes are severe tropical storms that form in the southern Atlantic Ocean, Caribbean Sea, Gulf of Mexico, and in the eastern Pacific Ocean. http://static.howstuffworks.com/gif/hurricane-weather-opal.jpg

13. Hurricanes gather heat and energy through contact with warm ocean waters. As the warm seawater evaporates into the storm, it increases the intensity of the hurricane. http://coastal.er.usgs.gov/hurricanes/rita/images/hurricane-ritaLG.jpg

14. Hurricanes rotate in a counter-clockwise direction around an "eye." Hurricanes have winds at least 74 miles per hour. The heavy waves are called a storm surge. Storm surges are very dangerous to the public. In addition, wind driven waves are connected with the storm tide. This is a major reason why you MUST stay away from the ocean during a hurricane warning or hurricane. http://www.angryconservative.com/home/Portals/0/Blog/GlobalWarming/hurricane.jpg

15. In this picture tropical storm Katrina had just become the eleventh named storm of the 2005 Atlantic Hurricane season.

16. The map below (dated August 28, 2005) from the National Hurricane Center shows Katrina's predicted path for the upcoming three to five days. http://www.nasa.gov/vision/earth/lookingatearth/h2005_katrina.html