1. Bellwork10/20/14 Lab papers from the cloud experiments need to be turned in the black tray. There are journals on the floor, if you do not have yours (from conferences) it should be found there. Where have you heard the words air mass and front before? If you haven’t heard these words, what do you think they mean?

2. Vocabulary Air Mass: a large volume of air in which temperature and humidity are nearly the same in different locations at the same altitude Front: a boundary between air masses High-Pressure System: formed when air moves all the way around high-pressure center Low-Pressure System: a large weather system that surrounds a center of low pressure

3. Characteristics of an Air Mass Depend on the region where the air mass forms and temp… Where do “maritime” air masses begin?

4. Movement of An Air Mass Air masses in the US move along with the jet streams – Do the air masses move North to South or West to East? – How would speed affect how the characteristics of an air mass? Justify your answer!

5. What are the two characteristics of an air mass that you need to know in order to classify it?

6. Weather changes where air masses meet The weather near a front can differ from the weather inside the rest of an air mass. As one air mass pushes another, some of the air at the boundary will be pushed upward. The weather often becomes cloudy or stormy as a front passes. Afterward, you experience the temperature and humidity of the air mass that has moved in.

7. Fronts and Weather Tells you which way the air will change (cold front, warm front, stationary front)

8. Pg. 579-Diagram

9. With your teams… Read and take notes on page 580-581.

10. What happens when a warmer air mass pushes a cooler air mass? Justify your answer! – A) cold front – B) warm front – C) stationary front

11. What type of weather system brings calm clear weather? JUSTIFY! – High- pressure – Low- pressure

12. Compare and Contrast: Explain how air moves differently in low- and high- pressure systems.

13. Apply: If the weather becomes stormy for a short time and then becomes colder, which type of front has passed?

14. Synthesize: You check a barometer and observe that the air pressure has been dropping all day. Is tonight’s weather more likely to be calm or stormy?