1. Air Masses and Fronts

2. What changes do you feel in the weather right before a thunderstorm? • Skies get dark • Gets windy • Gets colder

3. Recipe for a storm • Compare the skies between a thunderstorm and a tornado. • Do you see any similarities? • Do you see any differences?

4. Thunderstorms

5. Tornadoes

6. Can air move around?

7. Air Mass animation • http://www.classzone.com/books/earth_science/terc/content/visualizations/es2001/es2001page01.cfm?chapter_no=visualization • All around the earth, large masses of air move around and constantly change the weather. • They are named based on where they are coming FROM.

8. What type of weather would the following air masses bring?

9. What do the following terms mean? • Continental • Land • Maritime • Water • Polar • cold • Tropical • warm

10. Copy the following slides on page 14 of your Interactive Notebook • If it is in YELLOW, you are to copy it in your notebook. • Title the page “Air Masses Descriptions”

11. There are four types of air masses. • Air masses are named based on where they are coming FROM

12. Continental Polar • Cold, dry air mass that forms over central and northern Canada and Alaska

13. Continental Tropical • Hot, dry air masses that form over Southwest and northern Mexico

14. Maritime Polar • Cool, humid air masses that form over the icy cold North Pacific and North Atlantic oceans.

15. Maritime Tropical • Warm, humid air masses that form over tropical oceans such as the Gulf of Mexico

16. Classifying Air Masses

17. Write on page 13:Fronts Activity • Listen to the instructions • Do activity

18. On page 13 of your Interactive Notebook, answer the questions below. • The water represents air. Knowing this, explain how you think air behaves when air of different temperature meet. • Write your answer in complete sentences. • Using the color pencils, draw what you made and label.

19. Fronts (Copy on page 13) • A boundary created when two air masses meet. • Fronts are named for the air mass that is moving.

20. In the activity that we just did… • Where is the “front”?

23. Fronts animation • http://www.classzone.com/books/earth_science/terc/content/visualizations/es2002/es2002page01.cfm?chapter_no=visualization

24. Fill in the “Weather Fronts” chart as you follow along the next few slides.

25. Cold Front • Cold dense air moves in and pushes warm air out of the way • Cold fronts move very quickly and bring short periods of rain/thunderstorms • Lower temperatures are behindthe front • SYMBOL – the direction of the “arrows” points towards the direction the front is MOVING

27. A cold front

28. Warm Front • Warm air moves up the cold front as it slowly displaces and overtakes the cold air • Warm fronts move slowly, and bring many days of steady precipitation • Higher temperatures are behind the front • SYMBOL – direction of “half-moons” is the direction the front is moving

30. Warm front

31. Animations • http://www.classzone.com/books/earth_science/terc/content/visualizations/es2002/es2002page01.cfm?chapter_no=visualization • Cold front • Links to cold front videos

32. Stationary front • Created when cold and warm masses meet but neither one has enough force to move the other out of the way. • The water vapor in the warm air condenses into rain, fog, snow, clouds. • Can bring many days of precipitation

34. Links • Stationary front videos

35. Occluded front • Is created when a warm air mass is caught between two cooler air masses. • The two denser cooler air masses cut off the warm air mass from the ground. • As the warm air mass cools, it may turn cloudy, rainy or snowy.

37. Watch video clip of a weather report. • http://www.youtube.com/watch?v=HQrB37YQo9Y start at 2:10 • http://www.youtube.com/watch?v=OdcCMn5sbzM&feature=related start at 1:30 • http://www.youtube.com/watch?v=nS1nwfRUaaU&feature=related start at :30

38. Do a weather report

40. Use the graphic organizers and your interactive notebook to complete your homework.