CHAPTER 6: AIR MASSES & WEATHER PATTERNS METEOROLOGY NAME: PERIOD: Chapter 6 - Air Masses & Weather Patterns 1 Mr. Mihalik, Room 442
YOUR SHOT AT FORECASTING The project we ve all been waiting for... you finally get your shot at being a weather forecaster. In real life, a lot of work goes on behind the scenes, but meteorologists must also be able to communicate their scientific knowledge to all the viewers. For this project, you will only have about 30 viewers and the knowledge you need is relative basic compared to what Ed Hanna deals with on a daily basis. What you ll be doing... You will all be standing up in the front of the classroom and a weather map will appear behind you on the board. You will not see these weather maps in advance and they will be different from one another. In that moment, you re expected to identify the different types of fronts and air masses that are affecting the weather in our country. You ll be expected to see a front and give a forecast for different regions based on the front. For example, if you see a cold front moving through Pennsylvania, tell us what the people in Pennsylvania should expect to see with the weather. Not only are you expected to provide info on the weather for that current moment, but you re also going to be expected to provide an extended outlook for different parts of the country. For example, identify which direction certain fronts are going and you should be able to predict what will happen 1-2 days ahead based on the direction of the front. We will spend some time watching undergraduate students at Mississippi State University give their weather forecasts and you ll quickly be able to identify those traits, habits, trends, etc... that rookies make, but you won t see on The Weather Channel. Not only are you expected to provided accurate meteorological information, but you are going to be expected to have some level of competence talking to a group of people. Chapter 6 - Air Masses & Weather Patterns 2 Mr. Mihalik, Room 442
NORTH AMERICAN AIR MASSES A I R M A S S S O U R C E R E G I O N C H A R A C T E R I S T I C S A S S O C I A T E D W E A T H E R ca Arctic basin; Greenland ice cap cp Interior Canada; Alaska mp North Pacific mp Northwestern Atlantic ct Northern Mexico; southwestern U.S. mt Gulf of Mexico, Caribbean mt Subtropical Pacific Chapter 6 - Air Masses & Weather Patterns 3 Mr. Mihalik, Room 442
NORTH AMERICAN AIR MASSES AIR MASSES & SIGNIFICANT STORMS Lake-Effect Snow: Nor easter: Chapter 6 - Air Masses & Weather Patterns 4 Mr. Mihalik, Room 442
AFC Bracket New England Patriots NY Jets Miami Dolphins Buffalo Bills Baltimore Ravens Houston Texans Cincinnati Bengals Indianapolis Colts Denver Broncos Kansas City Chiefs Oakland Raiders Cleveland Browns San Diego Chargers Tennessee Titans Jacksonville Jaguars Pittsburgh Steelers Philadelphia Eagles NFC Bracket New Orleans Saints Green Bay Packers Tampa Bay Buccaneers New York Giants Dallas Cowboys Washington Redskins Atlanta Falcons Minnesota Vikings Carolina Panthers Arizona Cardinals Detroit Lions Seattle Seahawks Chicago Bears St. Louis Rams San Francisco 49ers Chapter 6 - Air Masses & Weather Patterns 5 Mr. Mihalik, Room 442
SNOW & NFL FOOTBALL Chapter 6 - Air Masses & Weather Patterns 6 Mr. Mihalik, Room 442
Frontal storms occur when two air masses meet. The temperature and humidity of the two air masses are different. Since one of the air masses is colder and drier than the other, it is called a cold air mass. The other air mass is called a warm air mass. When the air masses meet, they do not mix. A front forms between the two air masses. It is along this front that a low pressure area may form and a frontal storm may develop. This type of storm is very common in other parts of the world in the middle latitudes between 30o and 60o latitude. In the Northern Hemisphere, the winds around the low pressure area that forms the center of the storm move in, around, and up. Since the storms are found in the middle latitudes, the storms travel from west to east with the westerly winds. In winter, a cold air mass from Canada often moves down into the United States. A warmer air mass containing a great deal of water vapor moves into the United States from over the tropical waters of the Atlantic and the Gulf of Mexico. The map shows a cold air mass moving into the United States from the north and a warm air mass moving into the United States from the south. Frontal Storm Maps 1. Complete the blanks by writing the correct letter from the map in the blanks next to the terms. Warm, moist air mass from Gulf of Mexico Frontal boundary Cold air mass from Canada A H B C H Chapter 6 - Air Masses & Weather Patterns 7 Mr. Mihalik, Room 442
Chapter 29 WORKSHEET Chapter 29: Air Masses and Fronts Directions: Answer the questions below using the Earth Science books in the classroom. You will be allowed to use these completed worksheets on the open-notes test this chapter. Section I: Air Masses 1. What is an air mass? 2. Explain how an air mass originates. 3. How are air masses named? 4. Write the full name, characteristics, and source regions of the North American air masses abbreviated by: a. cpb. mpc. mtd. cte. ca- 5. Briefly describe the weather in each of the following air masses: a. cpb. mpc. mt- 6. How does the speed of the air mass affect the expected weather? 7. What is the chief factor that determines the type of skies an air mass will have? 8. Describe the sky conditions in an air mass resting on a cooler surface. 9. Describe the sky conditions in an air mass resting on a warmer surface. Chapter 6 - Air Masses & Weather Patterns 8 Mr. Mihalik, Room 442
Section II: Fronts and the Formation of Lows 10.What is a front? 11.Describe the relative positions of the air masses at a front and give the slope of a typical front. 12. Why do fronts bring precipitation? 13.Describe the 3 main types of fronts. 14.Compare slopes of warm and cold fronts and explain why their slopes are different near the ground. Section III: Weather Associated with Lows, Fronts, and Highs 15.Give the typical sequence of weather as a low passes to the north. 16.List the sequence of clouds that comes before and during the passing of a warm front at the surface. 17. Describe the clouds, precipitation, and weather changes that occur as a cold front passes. Chapter 6 - Air Masses & Weather Patterns 9 Mr. Mihalik, Room 442
MOVING AIR MASSES LED BY FRONTS 1. To show where the warm and cold air is located, write the words WARM and COLD on the proper side of each front to the right. 2. Which direction is the warm front moving? 3. Which direction is the cold front moving? 4. Draw a warm or cold front on the maps below. Use the wind and front direction arrows to help you decide which type of front to draw, and the direct it is moving. 5. Along a front, which air is always forced up? A. The wettest air B. Warmer, less dense air C. The fastest moving air D. The driest air 6. High-pressure systems usually are associated with and low-pressure systems are associated with. A. Clouds and precipitation, fair weather B. The jet stream, fronts C. Fair weather, clouds and precipitation D. Fair weather, fair clouds 7. In the Northern Hemisphere, winds in a cyclone blow: A. Clockwise toward the center B. Counter clockwise toward the center C. Sometimes clockwise, otherwise straight D. Clockwise outward from center Chapter 6 - Air Masses & Weather Patterns 10 Mr. Mihalik, Room 442
8. List the different fronts shown on the weather map. 9. What kind of air mass would the North Atlantic be in? 10.In what direction is the front near Phoenix moving? 11.What is the definition of an air mass? 12.What kind of front is near Denver? 13.What kind of front is north of Chicago? 14.What kind of air mass would be over Great Falls? 15.Would Los Angeles have clear or cloudy skies? Explain. 16.What kind of air mass would Washington D.C. experience? Chapter 6 - Air Masses & Weather Patterns 11 Mr. Mihalik, Room 442
AIR MASSES & FRONTS WEBSEARCH Site 1: http://itg1.meteor.wisc.edu/wxwise/ackermanknox/chap9/airmass_rev.html 1. What is an air mass? 2. Where do polar and tropical air masses develop? (Give the approximate latitudes.) 3. For each of the four air masses, what is the description this website gives? Site 2: http://www.srh.weather.gov/srh/jetstream/synoptic/airmass.htm 4. Why is the United States not a great place for air masses to form? Site 3: http://www.usatoday.com/weather/tg/wamsorce/wamsorce.htm 5. This site describes five basic types of air masses. In class on Friday, we learned about four types. Write the name of the new air mass and give two important facts about it. 6. Label the air masses on the map with the appropriate abbreviation. 7. What do the letters K or W mean when attached to an air mass? 8. When does America have typically have its most violent weather? Why? Chapter 6 - Air Masses & Weather Patterns 12 Mr. Mihalik, Room 442
Site 4: http://www.classzone.com/books/earth_science/terc/content/visualizations/es2001/es2001pag e01.cfm?chapter_no=visualization 9. In the first illustration, what kind of air mass is passing over the region? What type of weather will it bring? 10. In the second illustration, what kind of air mass is passing over southern California? What type of weather will it bring? Site 5: http://www.classzone.com/books/earth_science/terc/content/visualizations/es2002/es2002pag e01.cfm?chapter_no=visualization 11. Click on the Cold Front. What happens in the illustration? 12. Click on the Warm Front. What happens in the illustration? 13. In both the cold front and the warm front, warm air rises and cold air stays near Earth s surface. How are they different? Site 6: http://ww2010.atmos.uiuc.edu/%28gh%29/guides/mtr/af/frnts/cfrnt/def.rxml 14. What is a cold front and in what direction does one typically move? 15. How are cold fronts represented on a weather map? 16. From the chart at the bottom of the page, what happens to the wind as a cold front passes through? What about the precipitation? Chapter 6 - Air Masses & Weather Patterns 13 Mr. Mihalik, Room 442
Site 7: http://ww2010.atmos.uiuc.edu/%28gh%29/guides/mtr/af/frnts/wfrnt/def.rxml 17. What is a warm front and in what direction does one typically move? 18. How are warm fronts represented on a weather map? 19. From the chart at the bottom of the page, when a warm front passes through an area, what happens to the temperature and precipitation levels in that area? Site 8: http://www.usatoday.com/weather/tg/wsfront/wsfront.htm 20. What is a stationary front and what type of weather does one typically bring? 21. What is the weather map symbol for a stationary front? Site 9: http://www.atmos.illinois.edu/earths_atmosphere/airmasses_fronts.html 22. How does an occluded front form? 23. What is the weather map symbol for an occluded front? Site 10:http://itg1.meteor.wisc.edu/wxwise/AckermanKnox/chap9/airmass_Front.html 24. Visit the site listed above and see how well you do at locating the air masses. (Hint: Start with exercises 3 and 4 then go back to complete 1 and 2.) Chapter 6 - Air Masses & Weather Patterns 14 Mr. Mihalik, Room 442
CHAPTER 6 REVIEW SHEET 1. What is an air mass? 2. How are air masses classified? 3. What is a front? 4. Describe a cp air mass. 5. Describe a mp air mass. 6. Describe a ct air mass. 7. Describe a mt air mass. 8. Describe a ca air mass. 9. What would an air mass be like that forms over the Gulf of Mexico? 10.What would an air mass be like that originates over the North Pacific Ocean? 11.How is a mp air mass from the Pacific different than one from the Atlantic? 12.What is lake-effect snow? 13. Why is lake-effect snow such a big deal in the winter, but those same places don t get much rain in the summer? 14.What is a nor easter? 15. What is a cold front? 16. What is a warm front? 17. What is a stationary front? 18. What is an occluded front? Chapter 6 - Air Masses & Weather Patterns 15 Mr. Mihalik, Room 442
19. Which types of fronts move the fastest? 20. What type of weather is expected with a warm front? 21. What type of weather is expected with a cold front? 22. What type of weather is expected with a stationary front? 23. What type of weather is expected with an occluded front? 24. What does a warm front look like? 25. What does a cold front look like? 26. What does a stationary front look like? 27. What does an occluded front look like? 28. What does a Doppler show you? 29. What is a mid-latitude cyclone? 30. Identify the different types of fronts and air masses on the weather map below. Chapter 6 - Air Masses & Weather Patterns 16 Mr. Mihalik, Room 442