Chapter Resources for Differentiated Instruction Weatherog-science.wikispaces.com/file/view/Lesson+1+Variable… · · 2013-02-07Chapter Resources for Differentiated Instruction

Chapter Resources for Differentiated InstructionWeather

Title Page Lesson 1

Lesson 2

Lesson 3 Level

Get Ready to Read 1 all students

Quick Vocabulary 3 all students

Student Lab Safety Form 5 all students

Launch Lab 8 25 47 all students

Content Vocabulary ELL 9 26 48 all students

Lesson Outline ELL 10 27 49 all students

MiniLab 12 29 50 all students

Content Practice A 13 30 51 AL OL BL

Content Practice B 14 31 52 AL OL BL

Language Arts Support 32 all students

Math Skills 34 all students

School to Home 15 35 53 all students

Key Concept Builders 16 36 54 AL OL BL

Enrichment 20 40 58 all students

Challenge 21 41 59 AL OL BL

Lesson Quiz A 22 44 60 AL OL BL

Lesson Quiz B 23 45 61 AL OL BL

Skill Practice 42 all students

Lab A 62–64 AL OL BL

Lab B 65–67 AL OL BL

Lab C 68 AL OL BL

Chapter Key Concepts Builder 69 AL OL BL

Chapter Test A 70–72 AL OL BL

Chapter Test B 73–75 AL OL BL

Chapter Test C 76–78 AL OL BL

Answers (with Lesson Outlines) T2–T17

AL Approaching Level OL On Level BL Beyond Level ELL English-Language Learner

Teacher evaluation will determine which activities to use or modify to meet any ELL student’s proficiency level.

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Copyright © by The McGraw-Hill Companies, Inc. All rights reserved. Permission is granted to reproduce the material contained herein on the condition that such materials be reproduced only for classroom use; be provided to students, teachers, and families without charge; and be used solely in conjunction with the Glencoe Middle School Science program. Any other reproduction, for sale or other use, is expressly prohibited.

Send all inquiries to:Glencoe/McGraw-Hill8787 Orion PlaceColumbus, OH 43240-4027

ISBN: 978-0-07-891446-1MHID: 0-07-891446-9

Printed in the United States of America.

1 2 3 4 5 6 7 8 9 10 MAL 15 14 13 12 11 10

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iii

Title Frequency Overview Appropriate For

Get Ready to Read: What do

you think?

1/Chapter

Using the Get Ready to Read anticipation guide in the Student Edition? This page matches the anticipation guide in the Student Edition. Students can complete this at the beginning of a chapter and check their responses at the end.

all students

Quick Vocabulary

1/Chapter

Need some options to preteach vocabulary and help students with vocabulary development ? By folding the Quick Vocabulary sheet in half, students will have an easy reference tool. Lesson vocabulary, along with academic vocabulary, review vocabulary, or multiple-meaning words, are listed and defined. Students can add other words that they need to remember as well.

all students

Student Lab Safety Form

1/Chapter

Need a standard lab safety form? Each FastFile includes this form that students can complete prior to each lab. Students indicate that they understand all aspects of the lab. There is a place for the student and you to sign it.

all students

Launch Lab 1/Lesson

Want a lab recording page for Student Edition Launch Labs ? Each recording page matches the Student Edition Launch Labs, so students do not need to use their textbooks in the lab.

all students

Content Vocabulary*

1/Lesson

Want to help students who need more vocabulary practice? Content Vocabulary pages provide review and reinforcement activities. Use these pages to help students master content terms.

all students

Lesson Outline*

1/Lesson

Want an outline of the chapter for a substitute teacher, for absent students, or for students to use for review ? Lesson outlines follow the head and subhead structure of the Lesson, emphasizing the major content objectives. They can be used in many ways. In addition to those listed above, they can help you organize teaching notes and accompany student reading.

all students

MiniLab 1/Lesson

Want a lab recording page for Student Edition MiniLabs ? This recording page matches the Student Edition MiniLab, so students do not need to use their textbooks in the lab.

all students

AL Approaching Level OL On Level BL Beyond Level * ELL English-Language Learner


To The TeacherThis book contains reproducible pages that support the Student Edition. Descriptions and frequencies of these resources are listed in the table that follows.

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Content Practice

(Leveled)1/Lesson

Need more options for content review? Content Practice A is designed to help students who have difficulties learning and understanding the vocabulary and Key Concepts of each lesson:

• Form A—helps struggling students grasp lesson content

• Form B—provides on-level and beyond-level reinforcement of lesson content

AL AL AL

AL OL BL

Language Arts

Support1/Chapter

Looking for a way to help students build reading and writing skills in science? Language Arts Support pages provide practice using vocabulary, language structure clues, and writing skills with science content.

all students

Math Skills 1/ChapterWant help for students who need to practice math skills ? This page provides additional practice of the Math Skill in the Student Edition.

all students

School to Home

1/Lesson

Looking for a way to help students with the content ? The School to Home page provides support for a home-learning partner to help a student better understand the Big Idea of a chapter.

all students

Key Concept Builders

4/Lesson

Have students who need more practice with Key Concepts ? Key Concept Builders present the content in a context different from the Student Edition. These pages can be used whenever a student is struggling with any of the lesson’s Key Concepts.

AL AL AL

Enrichment 1/Lesson

Looking for ways to help students to broaden their understanding of lesson concepts ? Use Enrichment pages to further explore information and Key Concepts introduced in a lesson.

all students

Challenge 1/Lesson

Want to motivate the independent learner ? The Challenge activity extends information in the Student Edition and challenges a student’s abilities. The activity can be completed in class or at home.

AL AL BL

Lesson Quiz

(Leveled)1/Lesson

Need options to evaluate students after each lesson? These quizzes are developed around the Key Concepts of a lesson:

• Quiz A—provides more guided questions

• Quiz B—provides more short-answer and completion questions

AL

AL OL BL



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Skill Practice

1/Chapter

Need a lab recording page for the Skill Practice? This corresponds to the Skill Practice in the Student Edition. Write-on lines are included for answers. Tables/charts/graphs are included for recording observations, or space is provided for drawing tables/charts/graphs. Students do not need to use their textbooks in the lab.

all students

Lab (Leveled)

1/Chapter

Want leveled lab recording pages for the Lab in the Student Edition? These pages provide leveled versions of the Student Edition Lab. Write-on lines are included for answers. Tables/charts/graphs are often included for recording observations, or space is provided for creating tables/charts/graphs:

• Version A—This version follows the student edition lab but each step of the procedure is broken down sentence by sentence. Included are check-off boxes that provide easier processing for struggling learners.

• Version B—This version is the student edition lab.

• Version C—This version is designed to be a challenge for independent learners. Students must complete version B before doing version C.

AL AL AL

AL OL BL

AL AL BL

Chapter Key Concepts

Builder1/Chapter

Have students who need more practice with Key Concepts related to the Big Idea? This practice page is designed to reinforce chapter content for struggling students before they take the chapter test.

AL AL AL

Chapter Test

(Leveled)1/Chapter

Need options to assess each student according to his or her abilities ? These leveled chapter tests accommodate all students:

• Version A—provides students with more guided questions

• Version B—more short-answer and completion questions

• Version C—challenges students with more difficult and open-ended questions

AL AL AL

AL OL AL

AL AL BL

Teacher Pages

Want all the answers in one place? These pages contain the answers for all the practice pages.



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Name Date Class

WeatherWhat do you think?Before you read, decide if you agree or disagree with each of these statements. On the line before each statement, place an A if you agree or a D if you disagree. As you read this chapter, see if you change your mind about any of the statements.

Before You Read Statements After You

Read

1. Weather is the long-term average of atmospheric patterns of an area.

2. All clouds are at the same altitude within the atmosphere.

3. Precipitation often occurs at the boundaries of large air masses.

4. There are no safety precautions for severe weather, such as tornadoes and hurricanes.

5. Weather variables are measured every day at locations around the world.

6. Modern weather forecasts are done using computers.

What have you learned?After you read each lesson, return to this worksheet to see if you have changed your mind about any of the statements related to that lesson. Place a C after each statement that is correct or an I for those that are incorrect.

Get Ready to Read

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Name Date Class

Quick Vocabulary

Lesson 1

air pressure the pressure that a column of air exerts on the air or surface below it

dew point temperature at which air near the ground becomes fully saturated with water

humidity amount of water vapor in the air

kinetic energy the energy an object has due to its motion

precipitation water, in liquid or solid form, that falls from the atmosphere

relative humidity amount of water vapor present in the air relative to the maximum amount of water vapor the air can contain at that temperature

variable a quantity that can change

water cycle a series of natural processes in which water continually moves among oceans, land, and the atmosphere

weather atmospheric conditions of a certain place at a certain time

Lesson 2

air mass large body of air with distinct temperature and moisture characteristics

blizzard violent winter storm characterized by freezing temperatures, strong winds, and blowing snow

dominate to exert the guiding influence on

front boundary between two air masses

high-pressure system large body of circulating air that has high pressure at its center and lower pressure on the outside

hurricane intense tropical storm with winds exceeding 119 km/h

low-pressure system large body of circulating air that has low pressure at its center and higher pressure on the outside

tornado violent, whirling column of air that comes in contact with the ground

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4 Weather

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Quick Vocabulary

Lesson 3

computer model detailed program that solves a set of complex mathematical formulas

Doppler radar specialized radar that can detect precipitation and movement of small particles and can approximate wind speed

isobar line on a map used to connect all places where air pressure has the same value

surface report describes a set of weather measurements made on Earth’s surface

upper-air report describes wind, temperature, and humidity conditions above Earth’s surface

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Student Lab/Activity Safety Form

Student Name: Date:

Lab/Activity Title:

• Carefully read the entire lab and answer the following questions.

• Return this completed and signed safety form to your teacher to initial before you begin the lab/activity.

1. Describe what you will be doing during this lab/activity. Ask your teacher any questions you might have regarding the lab/activity.

2. Will you be working alone, with a partner, or with a group? (Circle one.)

3. What safety precautions should you take while doing this lab/activity?

4. Write any steps in the procedure, additional safety concerns, or lab safety symbols that you do not understand.

Date of Approval

Teacher Approval Initials

Student Signature

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Lesson 1 | Describing Weather

Student Labs and Activities Page Appropriate For:

Launch Lab 8 all students

Content Vocabulary ELL 9 all students

Lesson Outline ELL 10 all students

MiniLab 12 all students

Content Practice A 13 AL AL AL

Content Practice B 14 AL OL BL

School to Home 15 all students

Key Concept Builders 16 AL AL AL

Enrichment 20 all students

Challenge 21 AL AL BL

Assessment

Lesson Quiz A 22 AL AL AL

Lesson Quiz B 23 AL OL BL

Teacher Support

Answers (with Lesson Outlines) T2



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8 Weather

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Name Date Class

Launch Lab LESSON 1: 15 minutes

Can you make clouds in a bag?When water vapor in the atmosphere cools, it condenses. The resulting water droplets make up clouds.

Procedure 1. Read and complete a lab safety form.

2. Half-fill a 500-mL beaker with ice and cold water.

3. Pour 125 mL of warm water into a resealable sandwich bag and seal the bag.

4. Carefully lower the bag into the ice water. Record your observations in your Science Journal.

Think About This 1. What did you observe when the warm water in the bag was put into the beaker?

2. What explanation can you give for what happened?

3. Key Concept What could you see in the natural world that results from the same process?

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Name Date Class

Describing WeatherDirections: Write the correct term in the boxes to the right of each definition. Then unscramble the letters in the shaded boxes to spell a ninth term.

air pressure dew point humidity kinetic energy precipitation

relative humidity variable water cycle weather

Content Vocabulary

1. series of processes through which water moves around the globe

2. the amount of water vapor in the air compared to the maximum possible amount of water vapor the air can contain at that temperature

3. energy an object has because of its motion

4. atmospheric conditions at a certain place and time

5. a quantity that can be changed

6. a force exerted by a column of air

7. the amount of water vapor in the air

8. boundary at which water vapor becomes liquid water

9. When they are unscrambled, the letters from the shaded boxes spell

, which includes rain, snow, and sleet.

LESSON 1


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Name Date Class

Describing WeatherA. What is weather?

1. The atmospheric conditions, along with short-term changes, make up the

of a certain place at a certain time.

B. Weather Variables

1. Scientists who study and predict weather are .

2. Air is the measure of the average kinetic energy of

molecules in the air. Molecules in warm air move than molecules in cooler air.

3. is the pressure that a column of air exerts on the air or surface below it.

a. Air pressure decreases as altitude .

b. A(n) is an instrument used to measure air pressure.

4. is caused by air moving from an area of high pressure to an area of low pressure.

a. In a south wind, the wind is coming from the .

b. The instrument used to measure wind speed is a(n) .

5. The amount of water vapor in the air is .

a. When air is , it holds the maximum amount of water

vapor possible at that .

b. is the amount of water vapor in the air compared to the maximum amount of water vapor the air can hold at that temperature.

c. Relative humidity is reported as a(n) .

6. When air near the ground becomes saturated, the water vapor condenses into a

liquid and forms .

a. If the temperature is below 0°C, ice crystals, referred to as

, form.

b. The temperature at which air becomes fully saturated because the temperature decreases while the amount of moisture stays constant is

the .

Lesson Outline LESSON 1


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Name Date Class

Lesson Outline continued

7. As warm air rises in the atmosphere, it .

a. When the air cools enough that the is reached, small droplets of water form.

b. are water droplets or ice crystals suspended in the atmosphere.

c. is a cloud that forms near Earth’s surface.

d. clouds are flat, white, and layered.

e. clouds are fluffy and are present at 2,000 to 6,000 m altitude.

f. clouds are wispy and are present above 6,000 m altitude.

8. is water, in liquid or solid form, that falls from the atmosphere.

a. Precipitation that falls as liquid water is .

b. Precipitation that is solid crystals of ice is .

c. Precipitation that starts as snow and then melts and freezes again is

called .

d. is precipitation formed when ice pellets rise and fall within a cloud, adding new layers of ice during each cycle.

9. The is the series of natural processes in which water continually moves among oceans, land, and the atmosphere.

a. Water enters the atmosphere as water vapor when liquid water on Earth’s

surface .

b. As water vapor cools, it , forming liquid water.

c. Clouds produce , which is when liquid or frozen water falls to Earth’s surface.


12 Weather

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Name Date Class

MiniLab LESSON 1: 20 minutes

When will dew form?The relative humidity on a summer day is 80 percent. The temperature is 35°C. You want to find out if the dew point will be reached if the temperature drops to 25°C later that evening. Use the figure below to find the amount of water vapor needed for saturation at each temperature.

Procedure 1. Calculate the amount of water vapor in

air that is 35°C at 80 percent relative humidity. (Hint: multiply the amount of water vapor air can contain at 35°C by the percent of relative humidity.)

2. At 25°C, air can hold 2.2 g/cm3 of water vapor. If your answer from step 1 is less than 2.2 g/cm3, the dew point is not reached and dew will not form. If the number is greater, dew will form.

Analyze and Conclude Key Concept After the Sun rises in the morning, the air’s temperature increases.

How does the relative humidity change after sunrise? What does the line represent?

Maximum Water Vapor in Air

0 5 10 15 20 25 30 35 40 450

1

2

3

4

5

6

7

Wat

er v

apor

in a

ir (g

/m3 )

Temperature (°C)


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Name Date Class

Describing Weather

Rain Snow Sleet Hail

Directions: Use the diagram to answer each question.

Question Rain Snow Sleet Hail

What form is the water in when it is in the clouds— liquid or solid?

What is the air temperature near the clouds—warm or cold?

What is the air temperature near Earth’s surface—warm or cold?

What is the form of precipitation that falls—liquid or solid?

How are rain, snow, sleet, and hail part of the water cycle?

What role does temperature play in the type of precipitation that develops?

Content Practice A

Clouddroplets

Raindrops

Warm

Warm

Clouddroplets

Icecrystals

Snowflakes

Cold

Cold

Clouddroplets

Icecrystals

Raindrops

Cold

Warm

Clouddroplet

Icecrystal

Hail

Warm

LESSON 1

Describing Weather

Rain Snow Sleet Hail

Directions: Use the diagram to answer each question.

Question Rain Snow Sleet Hail

What form is the water in when it is in the clouds— liquid or solid?

What is the air temperature near the clouds—warm or cold?

What is the air temperature near Earth’s surface—warm or cold?

What is the form of precipitation that falls—liquid or solid?




14 Weather

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Name Date Class

Describing WeatherDirections: Explain how each variable contributes to weather in the space provided.

Air temperature 1.

Air pressure 2.

Wind 3.

Humidity 4.

Relative humidity 5.

Dew point 6.

Clouds 7.

Fog 8.

Precipitation 9.

Variables within the water cycle

10.

Evaporation in the water cycle

11.

Condensation in the water cycle

12.

Content Practice B LESSON 1


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Name Date Class

LESSON 1School to Home

Describing WeatherDirections: Use your textbook to answer each question.

1. Weather is the atmospheric conditions (and the short-term changes in those conditions) of a certain place at a certain time.

What variables do meteorologists use to describe weather?

2. Air pressure is the pressure that a column of air exerts on the air or surface below it.

What tool is used to measure air pressure?

3. When there is high humidity, there is a large amount of water vapor in the air.

What is the difference between humidity and relative humidity?

4. Water vapor can condense in the air, creating clouds and fog.

How are clouds and fog related to precipitation?

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Describing WeatherKey Concept What is weather?

Directions: Put a check mark in the correct column to answer the question about weather. Then explain each answer.

Does this fit the definition of weather? Yes No Why or why not?

1. It has been raining where you live for the past hour.

2. The average temperature in the summer is 42°C.

3. The temperature decreases 5°C in one hour and then decreases another 3°C in the next hour.

4. The day began sunny, but now there are plenty of clouds.

5. The region gets an average of 2.5 cm of rain each year.

6. You want to go on a bike ride, but you decide to go outside to check for dark clouds.

7. Heavy rainstorms are predicted for the next two hours, after which the sky should clear.

8. Ice formations are present across the region throughout the year.

9. Plants that require high amounts of moisture year-round grow in the area.

10. The clouds seem to be moving quickly, and the wind has started to blow harder.

11. The day began sunny, but now you wish you had an umbrella.

Key Concept Builder LESSON 1

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Name Date Class

Describing WeatherKey Concept What variables are used to describe weather?

Directions: Use the clues and the terms listed below to complete the puzzle.

air pressure air temperature barometric pressure dew point

humidity precipitation relative humidity

Key Concept Builder

CluesAcross 2. another term for air pressure

4. when water, in liquid or solid form, falls from the atmosphere

5. measure of the average kinetic energy of molecules in the air

6. amount of water vapor in the air

7. amount of water vapor in the air relative to the maximum amount of water vapor the air can contain at that temperature

Down 1. temperature at which air becomes fully

saturated

3. pressure that a column of air exerts on the air or surface below it

2

4

3

1

5

7

6

LESSON 1


18 Weather

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Name Date Class

Describing WeatherKey Concept What variables are used to describe weather?

Directions: Answer each question or respond to each statement in the space provided.

Variable Definition How is the variable measured?

Air temperature 1. 2.

Air pressure 3. 4.

Wind 5. 6.

Humidity 7. 8.

Relative humidity 9. 10.

Dew point 11. 12.

Clouds and fog 13. 14.

Precipitation 15. 16.



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Describing WeatherKey Concept How is weather related to the water cycle?

Directions: On the line before each statement, write T if the statement is true and F if the statement is false.

1. Precipitation, condensation, and evaporation are important to the water cycle.

2. The water cycle is a natural process.

3. In the water cycle, water is constantly added to the atmosphere, where it builds up over time.

4. Most water enters the atmosphere through surface runoff.

5. Water vapor warms as it rises in the atmosphere.

6. Water vapor that evaporates eventually condenses.

7. Clouds form from liquid water and ice.

8. Evaporation occurs when water falls from clouds.

9. Water enters the atmosphere when it condenses.

10. Thermal energy causes water at the ocean’s surface to evaporate.



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The Power Plant for WeatherThe Sun’s energy powers the weather,

from cloud formation to the entire water cycle. In fact, there would be no weather at all if we didn’t have the Sun. Earth receives less than a billionth of the energy that the Sun produces, but that is enough to run the water cycle, drive the weather, move ocean currents, maintain wind patterns, and enable photosynthesis.

Electromagnetic Energy The Sun drives most surface processes on

Earth. The energy to do this work arrives on Earth’s surface in the form of electromagnetic energy. Electromagnetic energy is radiated by the Sun in waves. The range of electromagnetic energy Earth receives is the electromagnetic spectrum. This spectrum includes rapid, high-energy gamma rays; X-rays; ultraviolet rays; visible light; infrared; microwaves; and long, slow radio waves. Each of these types of waves is distinguished by wavelengths in a particular range.

What causes weather? The Sun’s energy reaches Earth’s surface

as parallel rays. If Earth were a flat disk that faced the Sun, all parts of the surface would receive an equal amount of energy. But Earth presents a curved surface to the incoming electromagnetic radiation from

the Sun. Only one place on Earth—the equator—receives rays from the Sun straight on. All other areas receive rays at the angle of incidence. A location near the equator receives rays at a high, or more intense, angle of incidence, and a location near a pole receives rays at a low, or less intense, angle of incidence. The angle of incidence becomes increasingly lower with increasing latitude north or south. As Earth proceeds in its yearly orbit around the Sun, the angle of incidence varies with the seasons, except at the equator.

Variations in the intensity of energy from the Sun received on Earth’s surface cause thermal energy to be unequally distributed in the atmosphere. This energy tends to move toward a more even distribution. The movement of energy results in more or less constant changes in the atmosphere, which cause the weather.

Weather can be defined as the changes in the atmosphere at a given location for a short period of time. Earth’s rotation and orbit affect how much energy the parts of the surface receive from the Sun at any given time. Heating and cooling on a daily basis and on an annual basis drives changes in temperature, air pressure, winds, precipitation, humidity, cloud cover, and storms—all of which are weather variables.

Enrichment LESSON 1

Applying Critical-Thinking SkillsDirections: Respond to each statement.

1. Predict what Earth might be like without the Sun.

2. Explain in terms of angle of incidence why equatorial rain forests experience more vegetative growth and a wetter climate than other parts of Earth.

3. Summarize how typical weather conditions in the Amazon might differ from typical weather experienced in Anchorage, Alaska.

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LESSON 1

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Challenge

Tracking Temperature Select a position outside your home where you can comfortably and easily check and

record the outside temperature at least twice each day for a week. This will be your checkpoint. A convenient way to check the temperature is with a thermometer that hangs outside a window and can be read from the inside.

Collect and Compare DataChoose two times during the day when you can record a low temperature and a high

temperature. For example, record the temperature when you first get up in the morning, and again when you first come in from school in the afternoon. A sample chart is shown below. Choose a scale for your graph that is appropriate for the time of year.

When you have a week’s high and low temperatures in your chart, create a graph to display your data. Plot the lows in one color, and plot the highs in another color.

Temperature Data for Checkpoint:

Monday Tuesday Wednesday Thursday Friday Saturday Sunday

High

Low

Directions: Respond to each statement on the lines provided.

1. Identify the high and low temperatures for the week using the graph and your data.

2. Calculate the average high and average low temperatures for the week. Explain your method.

3. Explain how a meteorologist can use data like these to predict temperature changes from day to day and from year to year.

LESSON 1


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LESSON 1Lesson Quiz A

Describing WeatherMultiple ChoiceDirections: On the line before each question, write the letter of the correct answer.

1. Which variable is NOT weather related? A. humidity B. evaporation C. wind direction

2. Which instrument measures wind speed? A. barometer B. anemometer C. thermometer

3. A volume of air contains half the moisture that it can at a certain temperature. What is its relative humidity?

A. 25 percent B. 50 percent C. 75 percent

4. Which water cycle processes are directly related to cloud formation? A. melting and freezing B. precipitation and evaporation C. evaporation and condensation

MatchingDirections: On the line before each definition, write the letter of the term that matches it correctly. Each term is used only once.

5. solid crystals of precipitation

6. liquid precipitation

7. temperature when relative humidity is 100 percent

8. forms as water freezes and melts within a cloud

9. is greater in warm air than in cooler air

10. precipitation that starts in snow clouds

A. dew point

B. hail

C. humidity

D. rain

E. sleet

F. snow

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LESSON 1Lesson Quiz B

Describing WeatherCompletionDirections: On each line, write the term from the word bank that correctly completes each sentence. Not all terms are used.

anemometer barometer dew point hail humidity

rain sleet snow thermometer

1. is precipitation that reaches Earth’s surface as frozen water crystals.

2. A(n) is an instrument that measures air pressure.

3. Liquid precipitation that falls to Earth is known as .

4. Precipitation that changes from snow to rain and back to snow is

called .

5. The amount of water vapor in the air is known as .

6. The temperature at which the relative humidity is 100 percent

is .

7. is solid precipitation that forms in repeated updrafts within a cloud.

Short AnswerDirections: Respond to each statement on the lines provided.

8. Identify and briefly describe three variables of weather.

9. Explain the term relative humidity.

10. Describe how weather is related to the water cycle.

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24 Weather

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Lesson 2 | Weather Patterns








Language Arts Support 32 all students

Math Skills 34 all students





Skill Practice 42 all students

Assessment



Teacher Support





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LESSON 2: 10 minutes

How can temperature affect pressure?Air molecules that have low energy can be packed closely together. As energy is added to the molecules, they begin to move and bump into one another.

Procedure 1. Read and complete a lab safety form.

2. Close a resealable plastic bag except for a small opening. Insert a straw through the opening and blow air into the bag until it is as firm as possible. Remove the straw and quickly seal the bag.

3. Submerge the bag in a container of ice water and hold it there for 2 minutes. Record your observations in your Science Journal.

4. Remove the bag from the ice water and submerge it in warm water for 2 minutes. Record your observations.

Think About This 1. What do the results tell you about the movement of air molecules in cold air and in

warm air?

2. Key Concept What property of the air is demonstrated in this activity?

Launch Lab


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Weather PatternsDirections: Explain the differences between/among each set of terms on the lines provided. You must include the terms below in your answer.

1. high-pressure system, low-pressure system

2. tornado, hurricane

3. blizzard, winter storm

4. air mass, front

5. thunderstorm, dominate, dissipate

LESSON 2Content Vocabulary


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Lesson Outline

Weather PatternsA. Pressure Systems

1. A(n) is a large body of circulating air that has low pressure at its center and higher pressure on the outside.

a. Air moves from pressure to low pressure.

b. In a low-pressure system, air moves away from the of the system.

c. Air in the center of the system , and the water vapor in it condenses and forms clouds.

2. A(n) is a large body of circulating air that has high pressure at its center and lower pressure on the outside.

a. High-pressure air at the center and moves toward low-pressure areas.

b. High-pressure systems bring skies.

B. Air Masses

1. are large bodies of air that have distinct temperature and moisture characteristics.

2. An air mass forms when a(n) system lingers in one area for a few days.

a. Continental polar air masses are

and .

b. air masses are warm and humid.

c. air masses are very cold and dry. They form over

or arctic ice.

C. Fronts

1. A weather is the boundary between two air masses.

2. A(n) front forms when a colder air mass moves toward

a warmer air mass. It often brings severe and cooler temperatures.

3. A(n) front forms when a warmer air mass moves toward a cooler air mass.

a. As the warm air rises, water vapor condenses, and often occurs.

LESSON 2


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b. A warm front brings temperatures and shifting winds.

4. A(n) front forms when the boundary between two air

masses stalls. It brings skies and light rain.

D. Severe Weather

1. A low-pressure system can provide the warm temperatures, moisture, and rising air

needed for a(n) to form.

a. The stage of a thunderstorm starts with cloud formation and updrafts.

b. The stage of a thunderstorm contains heavy winds, rain, and lightning.

c. During the stage of a thunderstorm, wind and rain subside.

d. Lightning is caused by oppositely particles in clouds and on the ground.

2. A violent, whirling column of air that contacts the ground is

a(n) .

a. Tornadoes form when updrafts from thunderstorms begin

to .

b. is the name for the part of the United States that has the most tornadoes.

3. A(n) is an intense tropical storm with winds exceeding 119 km per hour.

a. Hurricanes typically form in late summer over warm, tropical

and are the largest type of severe storm.

b. When a hurricane moves over land or water, it loses energy.

4. A(n) is a severe winter storm, characterized by freezing temperatures, strong winds, and blowing snow.

5. The U.S. National Weather Service issues a(n) when

severe weather is possible. It issues a(n) when severe weather is already occurring.


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How can you observe air pressure?Although air seems very light, air molecules do exert pressure. You can observe air pressure in action in this activity.

Procedure

MiniLab

Analyze and Conclude 1. Interpret how air pressure affected the bottle.

2. Key Concept Discuss how changing air pressure in Earth’s atmosphere affects other things on Earth, such as weather.

1. Read and complete a lab safety form.

2. Seal an empty plastic bottle.

3. Place the bottle in a bucket of ice for 10 minutes. Record your observations in your Science Journal.

LESSON 2: 20 minutes


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Weather PatternsDirections: Complete these charts by choosing terms from the word bank and writing them in the correct spaces.

blizzards cold front freezing rain humidity

hurricanes occluded front stationary front temperature

thunderstorms tornado warm front

Content Practice A LESSON 2

1.

4.

5.

3.

2.

Types of Severe

Weather

Air Masses

6. 7.

8.

9.

10.

11.

4.


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Weather PatternsDirections: On the blank line, write the term from the word bank that correctly completes each sentence. Some terms may be used more than once or not at all.

air mass continental denser front

high-pressure system hurricane lighter low-pressure system

maritime occluded stationary thunder

thunderstorm tornadoes tropical warm

1. A(n) is the most destructive storm on Earth.

2. A(n) forms when a large, high-pressure system lingers over an area for several days.

3. An example of a(n) air mass is a polar air mass that forms over the northern Atlantic Ocean.

4. A boundary between two air masses is a(n) .

5. In a(n) , rising air cools and water vapor condenses, forming clouds.

6. Cold air pushes underneath warm air because it is .

7. In a(n) front, warm air glides over cold air.

8. A(n) front forms when a fast-moving cold front catches up with a slow-moving warm front.

9. The first stage of a(n) is when clouds form; this is the cumulus stage.

10. Rapidly expanding air molecules near a bolt of lightning cause a sound that is referred

to as .

11. Dry air masses that form over land are called air masses.

12. More occur in the United States than anywhere else.

13. An air mass that forms near the equator is a(n) air mass.

14. Other names for a(n) are tropical cyclone and typhoon.

LESSON 2Content Practice B


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Word-Usage Activity: Understanding Latin RootsThe word precipitate is a verb that comes from the Latin root praecipitatus, which means “to cast down headfirst.” Precipitate has various meanings including “to increase the occurrence of something” or “to cause something to happen suddenly.”

The storm damage precipitated an argument about the way government should respond to disasters.

The word precipitate is related to each of these words.

precipitation n. products of condensation in the air, such as rain, snow, and hailThe precipitation that fell during the storm was unusually heavy.

precipitous adj. extremely or impassably steepThe precipitous trails in the nearby mountains make them difficult to climb.

precipitate n. substance that is not soluble and condenses out of a solutionShe observed that a white precipitate formed when she mixed the two colorless solutions.

precipitant adj. hasty or rashThe result of his precipitant action is an example of why it is wise to think before you act.

Directions: On each line, write the term from the word bank that correctly completes each sentence.

precipitate precipitous precipitation precipitant

1. The weather report says that today’s includes rain mixed with snow.

2. Think carefully before you act so you do not make a decision.

3. The sure-footed mountain goats do not appear to be bothered by the

mountain paths.

4. A solid produced during a chemical reaction in a solution is a

.

Language Arts Support LESSON 2

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Word-Usage Activity: Using Scientific Words in Speech and Writing Directions: Write four complete sentences describing how weather influences people or how people perceive weather. Use the following terms in your sentences.

cold front hurricane relative humidity warm front

Example: A hurricane caused people to seek shelter from the high winds and rain.

1.

2.

3.

4.

Language Arts Support LESSON 2

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34 Weather

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Math Skills LESSON 2

ConversionsFahrenheit (°F) units and Celsius (°C) units are used to measure temperature. The Celsius scale is the standard unit of temperature used in nearly all countries in the world. To convert between Fahrenheit degrees and Celsius degrees, use these equations.

C = (F - 32)

_______ 1.8 F = (C × 1.8) + 32

The news report says that it is 42°F outside. What is the temperature in Celsius?

Practice 1. The thermometer on the classroom

wall reads 20°C. What is the temperature in degrees Fahrenheit?

2. It is 100°F on a summer day in San Antonio, Texas. What is the temperature in degrees Celsius?

3. It is 17°C in San Francisco, California, and 79°F in Cincinnati, Ohio. In which city is the temperature higher?

4. It is -11°C in Detroit, Michigan, and -3°F in Milwaukee, Wisconsin. In which city is the temperature lower?

Step 1 Select the correct equation.

C = (F - 32)

_______ 1.8

Step 2 Substitute the given value.

C = (42 - 32)

________ 1.8

Step 3 Subtract and then divide.

C = 10 ___ 1.8

C = 5.6°

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School to Home

Weather PatternsDirections: Use your textbook to answer each question.

1. High- and low-pressure systems cause air in a certain location to move. The movement of the air leads to certain weather conditions.

What kind of weather do low-pressure systems create? What kind of weather do high-pressure systems create?

2. Air masses are large bodies of air that have distinct temperature and moisture characteristics.

How are air masses classified?

3. A weather front is a boundary between two air masses.

What are the four types of weather fronts?

4. Severe weather can cause major damage. Severe weather includes thunderstorms, tornadoes, hurricanes, and winter storms.

Where and how do hurricanes form?

LESSON 2


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Weather Patterns Key Concept What are two types of pressure systems?

Directions: Use the diagrams to answer each question.

1. Where does air on the outside of a low-pressure system travel—toward the center or

outward?

2. Does air on the inside of a low-pressure system rise or fall?

3. Where does air on the inside of a high-pressure system travel—toward the center or

outward?

4. Does air on the inside of a high-pressure system rise or fall?

Directions: Answer each question on the lines provided.

5. What is a low-pressure system?

6. What is a high-pressure system?

L

Rising air

Surface

Low-pressure system

Subsiding air

SurfaceH

High-pressure system


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Weather PatternsKey Concept What drives weather patterns?

Directions: Work with a partner to answer each question on the lines provided.

Air Masses

Arctic Polar Tropical

1. Over what area does this air mass form?

2. What type of air does it contain?

3. How low does the air temperature reach?

Continental:4. Where do these air masses

form?

5. What type of air do they contain?

6. What kind of temperatures does this type of air mass bring?

Continental:10. Where do these air masses

form?


12. When do they usually form?

13. What type of weather do they bring?

Maritime:7. Where do these air masses

form?


9. What type of weather do they bring?

Maritime: 14. Where do these air masses

form?

15. What type of air do they contain in the summer?

16. What type of winter weather do they bring?

LESSON 2Key Concept Builder


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Weather PatternsKey Concept Why is it useful to understand weather patterns?

Directions: Work with a partner. Put a check mark in the space to identify the correct front(s).

Front

Weather Event Cold Warm Stationary Occluded

1. A colder air mass moves toward a warmer air mass.

2. An approaching front stalls.

3. Warm air glides above a cold air mass.

4. A fast-moving cold front catches up with a slow-moving warm front.

5. The boundary between two air masses stalls.

6. The wind becomes gusty and changes directions.

7. A wide blanket of clouds is created.

8. A few days of warm weather occur.

9. Warm air is forced to rise.

10. This is present at the edge of an approaching air mass.

11. This front moves faster than a warm front.

12. This usually brings precipitation.



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Weather PatternsKey Concept What are some examples of severe weather?

Directions: Answer each question in the space provided.


Thunderstorms

1. What happens in the cumulus stage?

2. What happens in the mature stage?

3. What happens in the dissipation stage?

4. What should you do to stay safe?

Tornadoes

5. How do tornadoes start?

6. How is a funnel cloud created?

7. What happens when the funnel cloud reaches the ground?


Hurricanes

9. What happens first?

10. How do the winds rotate?

11. What type of storm forms?

12. When does the storm become a hurricane?


Winter Storms

14. What happens when there is freezing rain? 15. Why are blizzards dangerous?


40 Weather

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The Benefits of Hurricanes

Enrichment

Hurricanes can be destructive, but they have been around as long as Earth has had an atmosphere. They are a natural part of the interactions of the atmosphere and oceans.

RainfallAs much as 25 percent of the available

rainfall in Japan, Southeast Asia, India, and the southeast United States is brought in by tropical storms and hurricanes. Hurricanes can carry enormous amounts of water. Although flooding can be associated with hurricane rains, the precipitation is vital for industries, farming, and drinking water that comes from lakes and groundwater.

Barrier IslandsBarrier islands are strips of sand that

form long, narrow islands parallel to the mainland. Over time, wave action forms and changes these islands. Just as dunes of desert sand move with the wind, barrier islands also move with the waves. Even as a hurricane erodes the beaches on the ocean front, it deposits sand on the back side of the island with the storm surge.

Thermal Energy ReliefEarth receives solar radiation most

directly along the equator and in the tropics, where most hurricanes are born. Some of this thermal energy is moved around by ocean currents, but most is

distributed by movements in the atmosphere, such as hurricanes. A hurricane is fed by evaporation from the surface of a warm sea. When the water vapor rises, it cools and condenses, releasing thermal energy into the atmosphere. A hurricane acts like an enormous chimney, pulling thermal energy up and out.

Coral ReefsHurricanes and coral reefs occur in

roughly the same latitudes. Coral reefs thrive in sunlit shallow waters. Hurricanes can destroy a reef, but it is thought that a hurricane can also benefit a coral reef community in several ways.

A hurricane can clear away dead organisms and wash debris outward to deeper water. It also sand-scours algae and breaks off fan and branched coral. These actions accomplish two things. First, they create available habitat in a teeming, crowded ecosystem. After a hurricane, colonization can occur where there was no room before. Second, it spreads broken coral to other areas where it can reproduce and colonize new areas.

An effect of overly warm tropical waters on coral reefs is called bleaching. The algae in the coral die, and this destroys the symbiotic relationship corals and algae have. A hurricane stirs deeper, cooler, restorative waters to the coral and helps prevent bleaching.

LESSON 2


1. Predict one possible pathway of ecological succession on a coral reef that has recently undergone some severe scraping and breakage by a hurricane.

2. Describe how a newspaper might report the effects of a massive hurricane going ashore in an unpopulated part of the world.


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Challenge

Lightning: Facts, Myths, and SafetyLightning is the discharge of electric energy as the result of a buildup of positive and

negative charges within a cumulonimbus cloud. The discharge moves toward the ground at about 96,000 km/s. Now that’s lightning speed!

The discharge, a thunderbolt, has a temperature of about 22,000°C, which is hotter than the surface of the Sun. The surrounding air becomes superheated and suddenly expands. Then it contracts just as quickly. This rapid expansion and contraction produces a loud sound called thunder. It occurs simultaneously with the lightning discharge, but light travels faster than sound. At a distance, the flash will be seen before the sound can be heard. Count the seconds between the flash and the sound. Every 3 seconds represents 1 km.

MythsThe tallest object on a landscape is not always struck first. The path of lightning is not

accurately predictable.Surge protectors will not save your TV, computer, or other electronics from lightning.

Surge protectors are designed to prevent damage by power surges between the power company and your house.

Benjamin Franklin was not struck by lightning. He saw the key on the end of his kite reacting to an electric field, so he wasn’t struck. It was a dangerous experiment, though.

The rubber tires on a car do not protect you in a lightning storm. But you are relatively safe in a car because the charge travels through the metal around the car and goes to the ground. Just don’t touch anything metal inside the car.

SafetyLightning is a spectacular show by nature that can be beautiful and awesome. Lightning

is also deadly. About 62 people, on average, are killed by lightning each year in the United States. Hundreds more are injured. The National Weather Service reports that for 2007, 45 people were killed and hundreds were injured. Of these,

• 98 percent were outside;

• 89 percent were male;

• 30 percent were males between the ages of 20 and 25;

• 25 percent were standing under a tree; and

• 25 percent occurred on or near the water.

Lightning is a serious danger. Use library resources to discover ways that people can protect themselves and their property. Design a brochure that summarizes the dangers of lightning. In your brochure, present ten rules for being safe in a lightning storm.

LESSON 2


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Why does the weather change? One day it is sunny, and the next day it is pouring rain. If you only look at one spot, the patterns that cause the weather to change are difficult to see. However, when you look on the large scale, the patterns become apparent.

Learn It Recognizing cause and effect is an important part of science and conducting experiments. Scientists look for cause-and-effect relationships between variables. The maps below show the movement of fronts and pressure systems over a two-day period. What effect will these systems have on the weather as they move across the United States?

Try It 1. Examine the weather maps below. The thin black lines on each map represent areas

where the barometric pressure is the same. The pressure is indicated by the number on the line. The center of a low- or high-pressure system is indicated by the word LOW or HIGH. Identify the location of low- and high-pressure systems on each map. Use the key below the maps to identify the location of warm and cold fronts.

Recognize Cause and Effect Skill Practice LESSON 2: 30 minutes

2. Find locations A, B, C, and where you live on the map. For each location, describe how the systems change positions over the two days.

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Skill Practice continued

3. What is the cause of and effect on precipitation and temperature at each location?

Apply It 4. The low-pressure system spawned several tornadoes. Which location did they occur

closest to? Explain.

5. The weather patterns generally move from west to east. Predict the weather on the third day for each location.

6. One day it is clear and sunny, but you notice that the pressure is less than it was the day before. What weather might be coming? Why?

7. Key Concept How does understanding weather patterns help make predicting the weather more accurate?

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Weather PatternsMultiple ChoiceDirections: On the line before each question, write the letter of the correct answer.

1. Which type of weather is associated with a maritime polar air mass? A. cloudy and rainy B. cloudy, warm, and dry C. warm, sunny, and clear

2. Which front brings several days of steady rain or snow into an area? A. a cold front B. a warm front C. a stationary front

3. When would a thunderstorm likely cause severe flooding? A. during its mature stage B. during its cumulus stage C. during its dissipation stage

4. Which air mass is warm and humid and forms over the ocean? A. maritime polar B. maritime tropical C. continental tropical

5. How does air move in a low-pressure system? A. toward the low-pressure area B. away from the low-pressure area C. clockwise around the low-pressure area

6. What are characteristics of a blizzard? A. swirling winds, a central eye, heavy rain B. low temperatures, strong winds, blowing snow C. rotating updrafts, high wind speeds, heavy rain

7. When might a beach area be evacuated? A. when a tornado watch is given B. when a hurricane warning is given C. when an occluded front is over the water

C173_044_045_CRF_L2Quz_891446.in44 44C173_044_045_CRF_L2Quz_891446.in44 44 10/5/09 4:15:16 PM10/5/09 4:15:16 PM

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Weather PatternsCompletionDirections: On each line, write the term that correctly completes each sentence.

1. Cloudy and rainy weather is associated with a(n) air mass.

2. A(n) front brings several days of steady rain or snow into an area.

3. A thunderstorm would likely cause severe flooding during its

stage.

4. A(n) air mass is warm and humid and forms over the ocean.

Short AnswerDirections: Respond to each statement on the lines provided.

5. Describe how air moves in a low-pressure system.

6. Identify which type of severe weather often poses a threat to Florida. Explain your reasoning.

7. Infer Would a thunderstorm warning or a tornado watch indicate an immediate need to take cover? Explain.


46 Weather

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Lesson 3 | Weather Forecasts












Lab A 62 AL AL AL

Lab B 65 AL OL BL

Lab C 68 AL AL BL

Chapter Key Concepts Builder 69 AL AL AL

Assessment



Chapter Test A 70 AL AL AL

Chapter Test B 73 AL OL AL

Chapter Test C 76 AL AL BL

Teacher Support





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Can you understand the weather report?Weather reports use numbers and certain vocabulary terms to help you understand the weather conditions in a given area for a given time period. Listen to a weather report for your area. Can you record all the information reported?

Procedure 1. In your Science Journal, make a list of

data you would expect to hear in a weather report.

2. Listen carefully to a recording of a weather report and jot down numbers and measurements you hear next to those on your list.

3. Listen a second time and make adjustments to your original notes, such as adding more data, if necessary.

4. Listen a third time and then share the weather forecast as you heard it.

Think About This 1. Which measurements were difficult for you to apply to understanding the weather report?

2. Why are so many different types of data needed to give a complete weather report?

3. List the instruments that might be used to collect each kind of data.

4. Key Concept Where do meteorologists obtain the data they use to make a weather forecast?

Launch Lab LESSON 3: 10 minutes


48 Weather

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Weather ForecastsDirections: On each line, write the term from the word bank that correctly replaces the underlined words in each sentence. NOTE: You may need to change a term to its plural form.

computer model Doppler radar isobar surface report

upper-air report

1. Tornadoes and thunderstorms, as well as other types of weather, can be tracked using a special system of measurement that can detect precipitation and can estimate wind speed.

2. On a weather map, high- and low-pressure systems are indicated by lines that connect

all places where pressure is the same.

3. Weather forecasts use information from sets of mathematical formulas calculated by

computer programs.

4. Information gathered by a weather station and by human observers is used to put together a(n) summary of weather measurements on Earth’s surface.

5. A(n) summary of weather conditions above Earth’s surface is based on measurements

made by a weather balloon.

Content Vocabulary LESSON 3


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Weather ForecastsA. Measuring the Weather

1. Meteorologists measure before making a forecast.

2. A(n) describes a set of weather measurements made on Earth’s surface.

3. Measurements include temperature, air pressure, humidity, precipitation, and wind

and .

4. A(n) describes wind, temperature, and humidity conditions above Earth’s surface.

5. A(n) is a package of weather instruments that are carried into the atmosphere by a weather balloon.

6. Satellites provide weather information by measuring the given off by Earth and by taking photographs.

7. images provide information about cloud temperature and height.

8. is a special form of radar that can be used to detect precipitation and approximate wind speed.

B. Weather Maps

1. The model displays many weather measurements for a

specific location. It appears on .

2. Weather maps have , which are symbols made up of lines that connect places that have equal air pressure. These lines give information

about .

3. are lines that connect places that have the same temperature.

4. are represented as lines with symbols on them.

C. Predicting the Weather

1. Modern weather forecasts are made with the help of .

2. are detailed computer programs that solve a set of

complex mathematical formulas. The formulas predict , winds, precipitation, and types of clouds.

Lesson Outline LESSON 3


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How is weather represented on a map?Meteorologists often use station models to record what the weather conditions are for a particular location. A station model is a diagram containing symbols and numbers that displays many different weather measurements. Use the station model legend provided by your teacher to interpret the data in each station model shown here.

MiniLab LESSON 3: 20 minutes

Analyze and Conclude 1. Compare and contrast the weather conditions at each station model.

2. Explain why meteorologists might use station models instead of reporting weather information another way.

3. Key Concept Discuss what variables are used to describe weather.

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Content Practice A

Weather ForecastsDirections: Complete this concept map by choosing terms from the word bank and writing them in the correct spaces.

Doppler infrared radar images satellite images

surface reports upper-air reports visible

1.

Tools Used to Gather Weather Information

6. 7.

5.

4. Type3. Type2.


8. What is a weather forecast?

9. How do weather maps help with weather forecasting?

10. How do computer models help with weather forecasting?

LESSON 3


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LESSON 3

Weather Forecasts

Content Practice B

Directions: Use the diagram to answer each question in the chart.

Station Model

What It Shows What It Tells

The temperature is 76°F.

1. What is the dew point temperature?

2. What does this tell you?

The barometric pressure is coded at 19.4.

3. What change in air pressure has occurred?


It is raining, and the wind is from the southwest.



6. What other information could be found on a weather map?

7. How might a computer model help make a weather forecast?

Barometric pressure coded

Temperature (°F)

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Type ofprecipitation

Dew pointtemperature

Change in pressure(in tenths of millibars)

Wind speedand direction


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Weather Forecasts

School to Home LESSON 3

Did you know? Interpreting data means carefully examining all the information available to you. The interpretations you make need to be based on accepted theories and an understanding of the information. Meteorologists analyze collected data, read satellite images, and interpret reports from weather stations to make a weather forecast.

For this activity, you will need access to weather radar images as well as weather data. This information is available on television news broadcasts, Web sites, or in local newspapers.

1. Collect and analyze the current weather conditions, including radar images, temperature, relative humidity, air pressure, wind speed and direction, and cloud coverage.

2. Use the information in Step 1 to create your prediction for the weather conditions for the next four days.

Day 1 Day 2 Day 3 Day 4

Chance (%) of precipitation

High temperature

Low temperature

3. Observe the weather over the next four days. Record whether precipitation occurred, as well as the high and low temperatures.

Day 1 Day 2 Day 3 Day 4

Precipitation? (yes/no)

High temperature

Low temperature

4. Did you correctly predict the weather? Explain.


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Weather Forecasts Key Concept Which instruments are used to measure weather variables?

Directions: Use your textbook to answer each question in the space provided.


Surface Report

Which variables are part of the report?

How does measuring this weather variable help people understand the weather?

1.

2.

3.

4.

5.

6.

7. How are the presence and characteristics of clouds determined?

Upper-Air Report

Which weather variables are measured and reported?

8.

9.

10.

11. What is a radiosonde?

12. What is the purpose of a radiosonde?


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Weather ForecastsKey Concept What instruments are used to measure weather variables?

Directions: On the line before each weather-related detail, write the letter of the term that matches it correctly. Some terms may be used more than once.

1. uses symbols to display information from surface and upper-air reports

2. can be visible or infrared

3. describes measurements of weather variables on Earth’s surface

4. orbit about 35,000 km above Earth

5. is especially useful for measuring wind speed during severe weather

6. describes what was measured by a radiosonde

7. measures the radiation given off by Earth

8. measures precipitation by bouncing radio waves off raindrops

9. detects precipitation as well as the movement of small particles

10. lines on a map that connect places of similar air pressure

11. includes a measurement of wind speed, air pressure, and precipitation

12. given twice daily at many locations around the world

13. show the location of high- and low-pressure systems

14. lines that connect places of similar temperatures

15. describes conditions above Earth’s surface

A. surface report

B. upper-air report

C. satellite image

D. radar image

E. station model

F. isobars

G. isotherms

H. Doppler radar

I. satellite


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Weather ForecastsKey Concept What instruments are used to measure weather variables?

Directions: Use the map to answer each question.

1. Which two types of fronts are shown on the weather map?

2. What type of air pressure system is located in the center of the country?

3. What pattern do the numbers on the map make?

4. Where are areas of high pressure located?

5. Where might a precipitation symbol be placed on this map?

6. How can this map be used to forecast the weather?

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Weather Forecasts Key Concept How are computer models used to predict the weather?

Directions: Computer models create detailed weather maps, such as this one. Use your knowledge of weather variables and weather maps to add to the weather map.

1. Draw lines in the area of high pressure.

2. Draw hash marks in the area of low pressure.

3. Draw arrows to show wind direction created by the warm front.

4. Draw arrows to show the wind direction created by the cold front.

5. Draw arrows showing wind direction in the area of low pressure above where the fronts collide.

6. Use the map to give your partner a general weather forecast.

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Doppler Radar

Enrichment LESSON 3

Meteorologists have many tools available to help them prepare weather forecasts. Accurate forecasts are important for giving people time to prepare for severe weather. With enough time, people can evacuate, find shelter, and take other measures to protect themselves. One of the newest tools for tracking and forecasting severe weather is Doppler radar.

The Doppler EffectThe Doppler effect is an apparent shift

in the observed frequency of a wave, due to the relative motion between the source and the observer. If you are standing still by the side of a road and a car is moving toward you with its horn blasting constantly, you will hear a shift in the sound as the car passes you. Sound waves stack up in front of the moving car, making the pitch higher. The pitch suddenly shifts downward when the car passes and the sound waves are stretching out behind the car moving away from you. By measuring the Doppler shift, the speed of an object can be determined with great accuracy. The Doppler effect can be observed with sound waves and electromagnetic waves, including colors in the visible spectrum.

RadarRadar stands for radio detection and

ranging. Radar uses electronic instruments

that transmit radio waves to determine the distance and location of other objects. Radar works by sending a pulse of radio waves toward a target or in a sweeping motion and then waiting to receive an echo. When the radar signal hits an object, the waves bounce off in all directions. Some are directed back toward the transmitter. The delay between the transmitted pulse and the received echo is used to determine the distance to the target.

Doppler RadarDoppler radar uses the Doppler effect to

measure a target’s velocity relative to the radar—the radar transmitter is the observer. This effect raises or lowers the frequency of the target echoes, depending on whether the target is moving toward or away from the radar. The difference between the radar’s transmitted frequency and the reflected echoes of the target is a measure of the relative speed of the radar and target.

Doppler radar can effectively image the precipitation in a thunderstorm from the reflection of the water droplets in the system. It can also determine its motion—how fast the rain or hail is moving toward or away from the transmitter. Since the 1980s, computer programs have been developed to enable Doppler radar to identify hail, heavy rain, severe downdrafts, and tornadoes forming on the ground.


1. Infer how a meteorologist might tell the difference between the Doppler echo of a weather system and of a flock of migrating geese.

2. Police use Doppler radar for traffic patrols. Explain the advantage of using Doppler radar over regular radar in traffic law enforcement.


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Challenge

Temperature Scales Most countries use the Kelvin, Celsius, or Fahrenheit scale to measure temperature.

Weather forecasters in the United States usually use Fahrenheit when reporting the weather on TV or in newspapers. Most people in the United States understand the Fahrenheit scale. Scientists use Celsius or Kelvin.

Converting Between Fahrenheit and CelsiusIf you travel outside the United States, would you understand whether to wear a jacket

or shorts and a T-shirt if the forecast says that it will be 30 degrees? In the United States, 30 degrees means it is very cold. In London, 30 degrees means shorts and a T-shirt.

Below are a few equations to help you convert temperatures. To convert from Celsius to Fahrenheit, use this equation: F = ( 9 __ 5 × C) + 32. Your work should look like this.

F = ( 9 __ 5 × 30) + 32

F = (1.8 × 30) + 32

F = 54 + 32

F = 86°

An easier conversion that you can do in your head works only from Celsius to Fahrenheit. Double the degrees Celsius: 30 × 2 = 60. Subtract one-tenth of this value: 60 - 6 = 54. Add 32: 54 + 32 = 86°F.

To convert Fahrenheit to Celsius, use the inverse of the other formula: C = (F - 32) × 5 __ 9 .For practice converting temperatures, fill in the table below. Convert Fahrenheit to

Celsius using the equation. Convert Celsius to Fahrenheit but first do the mental calculation. Round to the nearest whole degree.

°F °F (mental conversion) °C

32

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LESSON 3


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Weather Forecasts Multiple Choice Directions: On the line before each question, write the letter of the correct answer.

1. Which instrument measures air temperature? A. a barometer B. a thermometer C. an anemometer

2. Which tool would gather information for an upper-air weather report? A. a radiosonde B. a station model C. an anemometer

3. Which situation is NOT a use of Doppler radar? A. measuring wind speed B. detecting precipitation C. identifying weather fronts

4. What do closely spaced isobars indicate about wind? A. no wind B. weak winds C. strong winds

True or False Directions: On the line before each statement, write T if the statement is true and F if the statement is false.

5. Visibility is often measured using a radiosonde.

6. A visible satellite image is useful for determining cloud cover.

7. A station model is put together using only data from surface weather reports.

8. A cold front on a weather map is shown by a line of triangles.

9. Computer weather models are made by solving complex math formulas.

10. Isotherms connect places that have the same air pressure.



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Weather Forecasts CompletionDirections: On each line, write the term that correctly completes each sentence.

1. The data used to construct on a weather map are gathered with a barometer.

2. Data on upper-atmospheric weather conditions are gathered

with .

3. is often used to track tornadoes or thunderstorms.

4. Winds are when isobars are far from each other on a weather map.

5. Visibility is often measured by .

Multiple Choice Directions: On the line before each statement, write the letter of the correct answer.

6. The amount of cloud cover is determined using A. isotherms. B. a barometer. C. Doppler radar. D. visible satellite images.

7. A station model does NOT include A. wind speed. B. Doppler data. C. air temperature. D. type of precipitation.

8. Isotherms connect points on a weather map that have A. different elevations. B. different dew points. C. the same air pressure. D. the same temperatures.

9. Computer weather models do NOT A. predict which types of clouds will form. B. forecast the weather directly to the public. C. determine when and where precipitation will fall. D. solve complex mathematical equations to predict weather.



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Can you predict the weather? Weather forecasts are important. Forecasts help you plan what to wear when you leave the house. They also help farmers know when to plant and harvest their crops and help city officials know when to have snow plows ready to clear the streets. They also help officials decide when and where to send people when bad weather is headed their way.

Ask a QuestionCan you predict the weather?

Materialsgraph paper local weather maps

outdoor thermometer barometer

Make Observations 1. Read and complete a lab safety form.

2. Collect weather data daily for a period of one week. Temperature and pressure should be recorded as a number, but precipitation, wind conditions, and cloud cover may be described in words. Make your observations at the same time each day.

Day Temperature Pressure Precipitation Wind Cloud Cover

Lab A 40 minutes

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3. Graph temperature in degrees and air pressure in millibars below. Beneath the graphs, add notes that describe precipitation, wind conditions, and cloud cover for each day.

Air Pressure Temperature

Form a Hypothesis 4. Study your data and the weather maps. Look for factors that appear to be related. For

example, your data might suggest that when the pressure decreases, clouds appear.

5. Find three pairs of data that seem to be related. Form three hypotheses, one for each set of data pairs.

Lab A continued


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Lab A continued

Test Your Hypothesis 6. Look at your last day of data. Using your hypotheses, predict the weather for the next

day.

7. Collect weather data the next day and evaluate your predictions. Add to the table in step 2.

8. Repeat steps 6 and 7 for at least two more days. Add to the table in step 2.

Analyze and Conclude 9. Analyze Compare your hypotheses with the results of your predictions. How

successful were you? What additional information might have helped you make accurate predictions?

10. The Big Idea Scientists have more complex and sophisticated tools to help them predict their weather, but with fairly simple tools, you can make an educated guess. Write a one-paragraph summary of the data you collected and how you used them to predict the weather.

Communicate Your ResultsFor each hypothesis you made, make a small poster that states the hypothesis, shows a graph that supports it, and shows the results of your predictions. Write a concluding statement about your hypothesis. Share your results with the class.

Remember to use scientific methods.

Ask a Question

Form a Hypothesis

Test your Hypothesis

Analyze and Conclude

Communicate Results

Make Observations


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Can you predict the weather?Weather forecasts are important—not just so you are dressed right when you leave the house, but also to help farmers know when to plant and harvest, cities know when to call in the snow plows, and officials know when and where to evacuate in advance of severe weather.

Ask a QuestionCan you predict the weather?

Materialsgraph paper local weather maps

outdoor thermometer barometer

Make Observations 1. Read and complete a lab safety form.

2. Collect weather data daily for a period of one week. Temperature and pressure should be recorded as a number, but precipitation, wind conditions, and cloud cover may be described in words. Make your observations at the same time each day.

Day Temperature Pressure Precipitation Wind Cloud Cover

40 minutesLab B


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3. Graph temperature in degrees and air pressure in millibars on the graphs below. Beneath the graphs for each day add notes that describe precipitation, wind conditions, and cloud cover.

Title: Title:

Lab B continued

Form a Hypothesis 4. Examine your data and the weather maps. Look for factors that appear to be related.

For example, your data might suggest that when the pressure decreases, clouds follow.

5. Find three sets of data pairs that seem to be related. Form three hypotheses, one for each set of data pairs.

Test Your Hypothesis 6. Look at your last day of data. Using your hypotheses, predict the weather for the next

day.


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7. Collect weather data the next day and evaluate your predictions. Add to the table in step 2.

8. Repeat steps 6 and 7 for at least two more days. Add to the table in step 2.

Analyze and Conclude 9. Analyze Compare your hypotheses with the results of your predictions. How successful

were you? What additional information might have improved your predictions?

10. The Big Idea Scientists have more complex and sophisticated tools to help them predict their weather, but with fairly simple tools, you can make an educated guess. Write a one-paragraph summary of the data you collected and how you interpreted them to predict the weather.

Communicate Your ResultsFor each hypothesis you generated, make a small poster that states the hypothesis, shows a graph that supports it, and shows the results of your predictions. Write a concluding statement about the reliability of your hypothesis. Share your results with the class.

Lab B continued

Remember to use scientific methods.

Ask a Question

Form a Hypothesis

Test your Hypothesis

Analyze and Conclude

Communicate Results

Make Observations

Extension

Investigate other forms of data you might collect and find out how they would help you to make a forecast. Try them out for a week and see if your ability to make predictions improves.


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Where does the water come from?Directions: Use the information and data from the Lab Can you predict the weather? to perform this lab.

You have collected data on weather variables such as temperature, precipitation, and cloud cover. But how are these three variables related? Design an experiment that investigates where the water that causes cloud formation and precipitation comes from.

Please note that you must complete Lab B before beginning Lab C. Have your teacher approve your design and safety procedures before beginning your experiment.

Lab C


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WeatherEnd-of-Chapter Practice Directions: Work with a small group. Become weather forecasters and create a weather map. Here is what you need to do to complete this activity:

As a group, review each lesson in the chapter. Complete the chart together.

Weather Variables: Weather Patterns:

Weather Map Symbols: Ways to Forecast the Weather:

Then create your weather map.

• What area will it cover?

• What weather variables will it show?

• What weather patterns will it show?

• What symbols will you use?

• Who will design the map?

• What material will you need?

• What will each person in the group do to help create the weather map?

• What does the map forecast?

• Who will act as the weather forecaster and present the map?

Present your group’s weather forecast to the class.

Your weather map and forecast should accomplish the following:

• convey information neatly and accurately

• make good use of weather symbols

• present an interesting weather forecast that is supported by the weather map

Chapter Key Concepts Builder

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Chapter Test A

Weather Multiple Choice Directions: On the line before each question or statement, write the letter of the correct answer.

1. Which topic is NOT a weather variable? A. Doppler radar B. air temperature C. relative humidity

2. Air moves outward from a A. stationary front. B. tropical air mass. C. high-pressure system.

3. A air mass has the greatest effect on weather in Florida. A. maritime polar B. maritime tropical C. continental tropical

4. A cold front brings to an area. A. severe storms B. steady rain or snow C. cloudy skies and light rain

5. Which type of precipitation does NOT reach Earth in a frozen form? A. hail B. rain C. snow

6. Hurricanes form when A. a cold front meets a warm front. B. updrafts in a thunderstorm rotate. C. warm, moist air rises over an ocean.

7. Air pressure is measured with a(n) A. barometer. B. anemometer. C. thermometer.

8. The amount of water vapor in the air relative to what that air could hold is the A. dew point. B. air pressure. C. relative humidity.

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MatchingDirections: On the line before each definition, write the letter of the term that matches it correctly. Each term is used only once.

9. the pressure that a column of air exerts on the air or surface below it.

10. temperature when air is fully saturated with water vapor

11. the atmospheric conditions, along with short-term changes, of a certain place at a certain time


A. dew point

B. humidity

C. pressure

D. weather

Interpreting a Diagram Directions: Use the diagrams to answer to each question or respond to each statement.

13. Define How do weather fronts like these form?

14. Identify the type of weather front shown in each diagram.

15. Describe what is happening to the air at Front B.

16. Understand Cause and Effect It is summer. Front A will be over your area at noon. Should you postpone your 2:00 P.M. picnic? Why or why not?

Chapter Test A continued

Warm air

Cold air

Front A

Warm air

Warm airCold air

Front B


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Short Answer Directions: Respond to each statement on the lines provided.

17. Describe how rain is related to the water cycle.

18. Contrast low-pressure systems and high-pressure systems.

19. Contrast surface weather reports and upper-air reports.

20. Explain briefly how computers are used to forecast weather.

Concept Application Directions: Respond to each statement on the lines provided. Use complete sentences.

21. Explain why a desert would not normally experience fog.

22. Relate air temperature to the type of precipitation that will fall.

Chapter Test A continued


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Chapter Test B

WeatherMultiple Choice Directions: On the line before each question or statement, write the letter of the correct answer.

1. Which weather variable is NOT directly related to air temperature? A. dew point B. air pressure C. wind direction D. relative humidity

2. Air moves a low-pressure system. A. downward and into B. downward and out of C. into and upward through D. toward the high pressure in

3. A air mass would have the greatest effect on weather in Alaska. A. maritime polar B. continental polar C. maritime tropical D. continental tropical

CompletionDirections: On each line, write the term(s) that correctly completes each sentence.

4. is the atmospheric conditions, along with short-term changes, of a certain place at a certain time.

5. Weather is most severe during a thunderstorm’s stage.

6. The amount of water vapor in the air compared to the amount the air can hold

is .

7. A(n) front forms when warmer air moves toward colder, denser air.

8. Data used to construct isobars would be measured with

a(n) .

9. Frost forms when the of air is below 0°C.

10. Cooler air has humidity than warmer air.


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11. originates in snow clouds and falls to Earth as small

particles.

12. When updrafts within a thunderstorm begin to rotate, a(n) can form.

13. are used to collect data on upper atmospheric conditions,

and collect weather data closer to Earth’s surface.

Interpreting a Diagram Directions: Use the diagrams to answer each question or respond to each statement.

14. Compare and contrast what is happening in each diagram.

15. Identify the type of weather associated with each front.

16. Understand Cause and Effect It is 9 A.M. on a summer day, and Front A is supposed to move into your area by 6 P.M. You are planning a trip to the beach, which is an hour away. Will the weather spoil your plans? Explain.

Chapter Test B continued

Warm air

Cold air

Front A

Warm air

Warm airCold air

Front B


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17. Describe how the water cycle affects Earth’s weather in terms of the three states of water.

18. Sequence the steps in the formation of a hurricane.

19. Infer how computers have changed weather forecasting.

Concept Application Directions: Respond to each statement on the lines provided. Use complete sentences.

20. Identify an area that would experience fog on a regular basis. Explain your choice.

21. Suppose a low-pressure system has formed over your area. Predict how the weather would change and explain the reason for the change.

22. The gym and your math classroom have the same humidity. The temperature in the gym is colder than it is in the math classroom. Identify the room that has the higher relative humidity and explain why.

Chapter Test B continued


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WeatherMultiple Choice Directions: On the line before each question, write the letter of the correct answer.

1. Which statement is true of weather variables? A. Dew point occurs when air is nearly saturated. B. Humidity increases with an increase in air temperature. C. Air pressure increases with distance from Earth’s surface. D. Wind speed and direction are directly affected by cloud cover.

2. Which statement is true of a high-pressure system? A. It brings clouds and precipitation into an area. B. It brings clear skies and fair weather into an area. C. Warm air moves into it and slowly rises through it. D. Cold air moves out of it and then slowly sinks into it.

3. Which statement is NOT true of precipitation? A. Snow forms when water vapor changes directly to a solid. B. Hail forms as droplets of water freeze around a piece of ice. C. Rain cannot fall in winter because temperatures are too cold. D. Sleet forms when raindrops freeze as they pass through colder air.

Completion Directions: On each line, write the term that correctly completes each statement.

4. Hawaii’s weather is most affected by air masses.

5. In a thunderstorm, downdrafts begin to form during the stage.

6. are often used to collect weather data over the open ocean.

7. Data used to construct weather map isotherms would be gathered with

a(n) .

8. Precipitation often falls when relative humidity is percent.

9. Air pressure would be in a valley than on a mountaintop.

10. is the atmospheric conditions, along with short-term changes, of a certain place at a certain time.

11. A person’s hair might get wavy or even frizzy on a day with humidity.

Chapter Test C


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Interpreting a Diagram Directions: Use the diagrams to respond to each statement.

12. Identify each front and explain how each front forms.

13. Label each occurrence of the four air masses on the diagrams.

14. Draw arrows to show the direction each air mass is moving on the diagrams.

15. Suppose it is winter. Explain how winds, air pressure, temperature, and relative humidity would change after Front B has moved through the area.

16. Suppose it is still winter. Predict what type of weather would occur if Front A lingers over the area.


17. Explain precipitation, condensation, and evaporation as they pertain to weather.

Chapter Test C continued

Front A Front B


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18. Compare and contrast low- and high-pressure systems in terms of air circulation and general weather conditions.

19. Define computer models as they pertain to weather and explain how computers have changed weather forecasting.

Concept Application Directions: Answer each question or respond to each statement on the lines provided. Use complete sentences.

20. Infer When are tornadoes most common in the United States? Explain your answer.

21. A student measures the temperature of a beaker of water. He slowly adds ice to the water and continues taking the temperature of the water. At a certain point, water condenses on the outside of the beaker. Explain what happened.

22. The bridge that connects San Francisco and Oakland, California, is commonly referred to as the Bay Bridge. Many photos of the bridge show it surrounded by fog. Identify the time of day when the photos were probably taken and explain how the fog forms.

Chapter Test C continued


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Teacher Pages Lesson Outlines for Teaching T2

Answers T7

Weather T1

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Lesson Outline for TeachingLesson 1: Describing WeatherA. What is weather?

1. The atmospheric conditions, along with short-term changes, make up the weather of a certain place at a certain time.

B. Weather Variables

1. Scientists who study and predict weather are meteorologists.

2. Air temperature is the measure of the average kinetic energy of molecules in the air. Molecules in warm air move faster than molecules in cooler air.

3. Air pressure is the pressure that a column of air exerts on the air or surface below it.

a. Air pressure decreases as altitude increases.

b. A(n) barometer is an instrument used to measure air pressure.

4. Wind is caused by air moving from an area of high pressure to an area of low pressure.

a. In a south wind, the wind is coming from the south.

b. The instrument used to measure wind speed is a(n) anemometer.

5. The amount of water vapor in the air is humidity.

a. When air is saturated, it holds the maximum amount of water vapor possible at that temperature.

b. Relative humidity is the amount of water vapor in the air compared to the maximum amount of water vapor the air can hold at that temperature.

c. Relative humidity is reported as a(n) percent.

6. When air near the ground becomes saturated, the water vapor condenses into a liquid and forms dew.

a. If the temperature is below 0°C, ice crystals referred to as frost, form.

b. The temperature at which air becomes fully saturated because the temperature decreases while the amount of moisture stays constant is the dew point.

7. As warm air rises in the atmosphere, it cools.

a. When the air cools enough that the dew point is reached, small droplets of water form.

b. Clouds are water droplets or ice crystals suspended in the atmosphere.

c. Fog is a cloud that forms near Earth’s surface.

d. Stratus clouds are flat, white, and layered.

e. Cumulus clouds are fluffy and are present at 2,000 to 6,000 m altitude.

f. Cirrus clouds are wispy and are present above 6,000 m altitude.

T2 Weather

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8. Precipitation is water, in liquid or solid form, that falls from the atmosphere.

a. Precipitation that falls as liquid water is rain.

b. Precipitation that is solid crystals of ice is snow.

c. Precipitation that starts as snow and then melts and freezes again is called sleet.

d. Hail is precipitation formed when ice pellets rise and fall within a cloud, adding new layers of ice during each cycle.

9. The water cycle is the series of natural processes in which water continually moves among oceans, land, and the atmosphere.

a. Water enters the atmosphere as water vapor when liquid water on Earth’s surface evaporates.

b. As water vapor cools, it condenses, forming liquid water.

c. Clouds produce precipitation, which is when liquid or frozen water falls to Earth’s surface.

Discussion QuestionName and explain what happens during the three natural processes that form the water cycle.

Liquid water evaporates into water vapor. Water vapor condenses to liquid water that forms clouds. During precipitation, liquid or solid water falls to Earth’s surface.

Weather T3


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T4 Weather

Lesson Outline for Teaching Lesson 2: Weather PatternsA. Pressure Systems

1. A(n) low-pressure system is a large body of circulating air that has low pressure at its center and higher pressure on the outside.

a. Air moves from high pressure to low pressure.

b. In a low-pressure system, air moves away from the outside of the system.

c. Air in the center of the system rises, and the water vapor in it condenses and forms clouds.

2. A(n) high-pressure system is a large body of circulating air that has high pressure at its center and lower pressure on the outside.

a. High-pressure air at the center sinks and moves toward low-pressure areas.

b. High-pressure systems bring clear skies.

B. Air Masses

1. Air masses are large bodies of air that have distinct temperature and moisture characteristics.

2. An air mass forms when a(n) high-pressure system lingers in one area for a few days.

a. Continental polar air masses are cold and dry.

b. Maritime tropical air masses are warm and humid.

c. Arctic air masses are very cold and dry. They form over continents or arctic ice.

C. Fronts

1. A weather front is the boundary between two air masses.

2. A(n) cold front forms when a colder air mass moves toward a warmer air mass. It often brings severe storms and cooler temperatures.

3. A(n) warm front forms when a warmer air mass moves toward a cooler air mass.

a. As the warm air rises, water vapor condenses, and precipitation often occurs.

b. A warm front brings warmer temperatures and shifting winds.

4. A(n) stationary front forms when the boundary between two air masses stalls. It brings cloudy skies and light rain.

D. Severe Weather

1. A low-pressure system can provide the warm temperatures, moisture, and rising air needed for a(n) thunderstorm to form.

a. The cumulus stage of a thunderstorm starts with cloud formation and updrafts.

b. The mature stage of a thunderstorm contains heavy winds, rain, and lightning.


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Weather T5


c. During the dissipation stage of a thunderstorm, wind and rain subside.

d. Lightning is caused by oppositely charged particles in clouds and on the ground.

2. A violent, whirling column of air that contacts the ground is a(n) tornado.

a. Tornadoes form when updrafts from thunderstorms begin to rotate.

b. Tornado Alley is the name for the part of the United States that has the most tornadoes.

3. A(n) hurricane is an intense tropical storm with winds exceeding 119 km per hour.

a. Hurricanes typically form in late summer over warm, tropical oceans and are the largest type of severe storm.

b. When a hurricane moves over land or cold water, it loses energy.

4. A(n) blizzard is a severe winter storm, characterized by freezing temperatures, strong winds, and blowing snow.

5. The U.S. National Weather Service issues a(n) watch when severe weather is possible. It issues a(n) warning when severe weather is already occurring.

Discussion QuestionWhich types of severe weather are common where you live? Which features of Earth’s surface where you live make this severe weather common?

Answers should relate temperature and proximity to bodies of water, mountains, or deserts to severe weather.


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Lesson Outline for Teaching Lesson 3: Weather Forecasts A. Measuring the Weather

1. Meteorologists measure weather variables before making a forecast.

2. A(n) surface report describes a set of weather measurements made on Earth’s surface.

3. Measurements include temperature, air pressure, humidity, precipitation, and wind speed and direction.

4. A(n) upper-air report describes wind, temperature, and humidity conditions above Earth’s surface.

5. A(n) radiosonde is a package of weather instruments that are carried into the atmosphere by a weather balloon.

6. Satellites provide weather information by measuring the radiation given off by Earth and by taking photographs.

7. Infrared satellite images provide information about cloud temperature and height.

8. Doppler radar is a special form of radar that can be used to detect precipitation and approximate wind speed.

B. Weather Maps

1. The station model displays many weather measurements for a specific location. It appears on weather maps.

2. Weather maps have isobars, which are symbols made up of lines that connect places that have equal air pressure. These lines give information about wind speed.

3. Isotherms are lines that connect places that have the same temperature.

4. Fronts are represented as lines with symbols on them.

C. Predicting the Weather

1. Modern weather forecasts are made with the help of computers.

2. Computer models are detailed computer programs that solve a set of complex mathematical formulas. The formulas predict temperature, winds, precipitation, and types of clouds.

Discussion QuestionLook at a forecast of today’s weather. How does the actual weather compare with the forecast?

Students should compare wind speed, temperature, precipitation, and other factors.

T6 Weather


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What do you think? (page 1) 1. Disagree; weather is the daily or short-term

atmospheric pattern.

2. Disagree; fog forms at ground level, and the highest clouds form in the lower stratosphere.

3. Agree

4. Disagree; weather watches and warnings are broadcast on radio and television. The National Weather Service provides evacuation plans.

5. Agree

6. Agree

Lesson 1Launch Lab (page 8) 1. Moisture collected on the sides of the bag in

fine droplets.

2. Some of the hot water in the bag evaporated into the air within the bag. When it was placed in the cold water, the water vapor condensed on the sides of the bag.

3. Clouds, including fog, form in this manner. Also, dew and frost collect on the surfaces of cool objects as warm, moist air comes in contact with them.

Content Vocabulary (page 9) 1. water cycle

2. relative humidity

3. kinetic energy

4. weather

5. variable

6. air pressure

7. humidity

8. dew point

9. precipitation

MiniLab (page 12) 1. 3.2 g/m3 (4 g/m3 × 0.80)

2. Students should note that dew will form, since 3.2 g/m3 is greater than the dew point.

Analyze and Conclude As the air temperature increases, the air can hold more moisture. The line in the graph represents the dew point, which is the maximum amount of moisture for that temperature.

Content Practice A (page 13) For completed table, see page T16.

Content Practice B (page 14) 1. Possible answer: Air temperature determines

whether precipitation falls as a liquid (rain) or a solid (snow, sleet, or hail). Air temperature also affects how much moisture the air holds.

2. Possible answer: Air pressure is used to predict weather. Changes in air pressure indicate a change in the weather.

3. Possible answer: Wind indicates direction and a change in air pressure. Increased wind speed is often associated with severe weather.

4. Possible answer: Humidity indicates the amount of moisture in the air and, thus, directly relates to the potential for precipitation.

5. Possible answer: Because it relates air temperature to humidity, relative humidity is used to predict the possibility of precipitation.

6. Possible answer: Dew point indicates the temperature at which precipitation will form and is used to predict where dew or frost will form.

7. Possible answer. The height and type (shape) of cloud are used to predict the type of weather that is possible, such as light rain, thunderstorms, snow, sleet, or hail.

8. Possible answer: Fog is clouds that form near Earth’s surface, so it reduces visibility. If ice crystals form in the cloud, dangerous surface conditions can exist.

9. Possible answer: Precipitation falls as rain, snow, sleet, or hail. The type of precipitation that falls is predicted based on air temperature and humidity levels.

10. Possible answer: The type of weather that a region experiences depends on what is happening at that place in the water cycle.

11. Possible answer: If water is evaporating and the humidity levels are low, then there is no precipitation.

12. Possible answer: If water vapor condenses and clouds form, then precipitation will fall. The type of precipitation that falls depends on air temperature.

School to Home (page 15) 1. The variables include air temperature, air

pressure, wind speed and direction, humidity, cloud coverage, and precipitation.

2. A barometer measures air pressure.

3. Humidity is the amount of water vapor that is present in the air at a given time. Relative humidity is the amount of water vapor in the air relative to the maximum amount of water vapor the air can contain at that temperature.

4. Clouds and fog keep water in vapor, liquid, or solid form in the atmosphere. When the water falls from the atmosphere in solid or liquid form, it is precipitation.

Key Concept Builder (page 16) 1. yes; It is an atmospheric condition that is

taking place for a short time at my house.

Answers

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Answers continued 2. no; It is not short term, but it describes the

temperature normally present in the summer.

3. yes; It is a short-term atmospheric condition.

4. yes; This describes a short-term atmospheric change.

5. no; This is not short term, but it describes an annual pattern.

6. yes; I am looking for any possible short-term changes in the atmospheric condition.

7. yes; The rains represent a short-term change in atmospheric conditions.

8. no; This represents annual temperatures that fall below freezing and are not short-term changes.

9. no; This is an annual pattern that is not representative of a short-term atmospheric condition.

10. yes; This represents a short-term atmospheric change.

11. yes; It has changed from a sunny day to rain, representing a short-term atmospheric change.

Key Concept Builder (page 17) 1. dew point

2. barometric pressure

3. air pressure

4. precipitation

5. air temperature

6. humidity


Key Concept Builder (page 18) 1. the measure of the average kinetic energy of

molecules the air

2. in Celsius or Fahrenheit with a thermometer

3. the pressure that a column of air exerts on the air or surface below

4. in millibars using a barometer

5. created as air moves from areas of high pressure to areas of low pressure

6. as speed using an anemometer


8. in grams of water per cubic meter of air

9. the amount of water vapor in the air compared to how much that air can hold at a particular temperature

10. in percent

11. the temperature at which air becomes fully saturated

12. by temperature and water vapor content

13. water droplets or ice crystals suspended in the atmosphere—referred to as fog when it is near Earth’s surface

14. by shape and altitude

15. water, in liquid or solid form, that falls from the atmosphere

16. in inches or centimeters

Key Concept Builder (page 19) 1. T

2. T

3. F

4. F

5. F

6. T

7. T

8. F

9. F

10. T

Enrichment (page 20) 1. Possible answer: Earth, the Moon, and the rest

of the solar system as we know it would be dark and lifeless and would exist as giant balls of ice in space. Even the internal thermal energy of the planet would not warm the surface enough for life to exist on Earth. The only light would come from the thermal energy of volcanic eruptions. There would be no weather or climate differences anywhere on the surface.

2. The angle of incidence for incoming energy from the Sun is high at the equator. This means that more intense energy arrives at the equator. More intense energy produces more warmth and powers evaporation, transpiration, and photosynthesis at a higher rate than it does at lower angles of incidence.

3. The typical weather in the Amazon is consistently warm and humid from evaporation and transpiration. Because water vapor cools and condenses as it rises, precipitation is more frequent than at higher latitudes. In Anchorage, the typical weather is likely dryer and cold. It receives less precipitation because it receives less intense energy from the Sun more of the time.

Challenge (page 21)As an alternative, students could obtain high and low temperatures from a local newspaper.

1. Students should identify two numbers—the highest high temperature and the lowest low.

2. Students should add the temperatures (highs and lows are calculated separately) and divide by seven.

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Answers continued 3. Meteorologists have data for longer periods of

time and can see changes that occur gradually, such as the change from one season to the next. If data for a certain period do not correlate with the same periods in the past, it might signal a long-term change.

Lesson Quiz A (page 22)Multiple Choice 1. B

2. B

3. B

4. C

Matching 5. F

6. D

7. A

8. B

9. C

10. E

Lesson Quiz B (page 23)Completion 1. Snow

2. barometer

3. rain

4. sleet

5. humidity

6. dew point

7. Hail

Short Answer 8. Students’ answers should include any three of

the following: Air temperature is a measure of the average kinetic energy of air molecules. Air pressure is the force exerted by a column of air. Wind direction is the direction from which the wind is blowing. Wind speed is how quickly or slowly the air is moving. Humidity is the amount of water vapor in the air. Relative humidity is the amount of water vapor in a volume of air compared to the maximum amount the air can hold at that temperature. Dew point is the temperature at which air near the ground becomes saturated and water condenses. Cloud cover is the amount and type of clouds in the sky. Precipitation is any form of water that falls to Earth from clouds.

9. Relative humidity is the amount of water vapor in a volume of air compared to the maximum amount of water vapor the air can hold at that temperature. A volume of air with a relative humidity of 75 percent can hold 25 percent more water vapor at that

temperature before it would become saturated and precipitation would form.

10. Weather is the condition of the atmosphere, and any short-term changes in its condition at a given time and place. Processes in the water cycle, such as precipitation, humidity, condensation, and evaporation have an effect on the weather conditions at a certain place.

Lesson 2Launch Lab (page 25) 1. The air in the bag in cold water contracts.

Upon placing the bag in warm water, the air expands. The molecules in warm air move with more energy, striking the inside of the bag with more force and taking up more space.

2. Air pressure is related to temperature.

Content Vocabulary (page 26) 1. A high-pressure system has high pressure at

the center of the body of air and lower pressure on the outside, and a low-pressure system has low pressure at the center and higher pressure outside. High-pressure systems bring clear skies, and low-pressure systems bring precipitation.

2. A tornado is a whirling column of air that contacts the ground, and a hurricane is a whirling storm that forms over the ocean.

3. A blizzard is a specific type of winter storm. During a blizzard, strong winds and blowing snow result in low visibility.

4. An air mass is a large body of air that has specific characteristics, and a front is the boundary between two different air masses.

5. A thunderstorm has a three-stage life cycle. Updrafts and cloud formations dominate, or guide, the first stage in a thunderstorm. At the third stage, these patterns dissipate, or fade.

MiniLab (page 29) 1. The air inside the bottle is a separate system

from the air outside the bottle, but they are balanced. As the air in the bottle is cooled, it exerts less force against the inside of the bottle, so the air outside the bottle crushes the bottle. The systems are still balanced, but the outside air exerts greater pressure.

2. Cold air masses have molecules that are spaced more closely together than warm air masses. The greater number of particles per unit of space in a cold air mass then weighs more and exerts more pressure on the ground. This pressure affects weather conditions, because their greater weight allows the cold air mass to push lighter masses out of the way. Colder masses move downhill with

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Answers continuedgravity, are affected by the Coriolis effect, and cool things they come in contact with; for example, moisture in the atmosphere forms clouds and precipitation.

Content Practice A (page 30) 1–5. (in any order) freezing rain, tornadoes,

hurricanes, blizzards, thunderstorms

6–7. (in either order) temperature, humidity

8–11. (in any order) cold front, warm front, stationary front, occluded front

Content Practice B (page 31) 1. hurricane

2. air mass

3. maritime

4. front

5. low-pressure system

6. denser

7. warm

8. occluded

9. thunderstorm

10. thunder

11. continental

12. tornadoes

13. tropical

14. hurricane

Language Arts Support (page 32) 1. precipitation

2. precipitant

3. precipitous

4. precipitate

Language Arts Support (page 33) 1–4. Possible Responses: The air feels damp and

sticky when the relative humidity is high. Our flight to Florida was canceled because of a hurricane. The air is usually cool, dry, and clear after a cold front passes. The air is usually warm, damp, and hazy as a warm front approaches.

Math Skills (page 34) 1. 68°F

2. 37.8°C

3. Cincinnati

4. Milwaukee

School to Home (page 35) 1. Low-pressure systems create clouds and

sometimes precipitation. High-pressure systems create clear skies and fair weather.

2. There are continental, maritime, tropical, polar, and arctic air masses,

3. The four types of fronts are cold fronts, warm fronts, stationary fronts, and occluded fronts.

4. Answers will vary but should include the following: Hurricanes typically form in late summer over warm, tropical ocean water. Moist, warm air rises above the ocean. The air then cools, and clouds form as water vapor condenses. The cool air sinks and moves toward the center of the area. It becomes a low-pressure system. Continued rising of warm, moist air; cooling; rain; and sinking, cool air allows the storm to grow in size and severity. When the winds reach 120 mph, it is classified as a hurricane.

Key Concept Builder (page 36) 1. toward the center

2. rises

3. outward

4. falls

5. A low-pressure system is a large body of circulating air that has low pressure at its center and higher pressure on the outside.

6. A high-pressure system is a large body of circulating air that has high pressure at its center and lower pressure on the outside.

Key Concept Builder (page 37) 1. Siberia and the arctic

2. bitterly cold and dry

3. -40°C

4. in the interior of Canada and Alaska

5. cold, dry air

6. cold temperatures in winter and cool weather in summer

7. over the northern Atlantic and Pacific oceans

8. cold and humid

9. cloudy and rainy

10. over dry, desert land

11. hot and dry

12. during the summer

13. clear skies and high temperatures

14. near the equator

15. hot and humid

16. heavy snowfall

Key Concept Builder (page 38) For completed table, see page T17.

Key Concept Builder (page 39) 1. Clouds form, and updrafts occur.

2. Heavy winds, rain, and lightning dominate the area.

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Answers continued 3. Updrafts cut off, winds die down, lightning

ceases.

4. Stay inside; stay away from water, high places, and electrical devices.

5. Thunderstorm updrafts begin to rotate.

6. Swirling winds spiral downward.

7. Dirt and debris are lifted upward; large objects are thrown.

8. Go to a basement, if possible.

9. An area of low pressure is created.

10. counter-clockwise

11. tropical storm

12. when wind exceeds 119 km/h

13. Leave the area before the hurricane arrives.

14. Ice coats the ground, trees, and buildings.

15. Skin cools rapidly, frostbite is possible, and hypothermia can set in.

Enrichment (page 40) 1. Students should research ecological succession

if they have not studied it. Possible answer: A hurricane can leave large areas of coral reef bare of algae, can break and scatter branched and fan coral, and can severely damage or reduce the populations of residents of the reefs. Over time, producers will return in the newly available habitats cleared by the storm. Then herbivores will return, followed by predators. The species variety might be slightly different, but abundance of all species will eventually return, barring further disturbance.

2. Reports are likely to indicate the strength of the hurricane, wind speed, storm surge, impacts on the landscape, direction of the hurricane overland, and how much rain to expect in populated areas. Reports may include loss of habitat or wildlife resources. Rarely do reports include that niches may have been cleared for further growth, patches of sunlight now appear on a forest floor, or other ecological benefits of a storm.

Challenge (page 41)Brochures should be informative, creative, and relevant. The NOAA National Weather Service, the National Lightning Safety Institute (NLSI), and most state departments of health have information about lightning safety. Students can contact local offices, such as the department of public safety, the state department of health, or local meteorologists for flyers and advice.

Skill Practice (page 42) 4. The tornadoes occurred closest to A, where

the cold front passed. Cold fronts are

associated with active convection and more violent weather, including severe thunderstorms and tornadoes.

5. Location A will have clear and cooler weather for the next day or so as a high-pressure system passes. Location B will experience first an increase in precipitation and a decrease in temperature as the cold front passes. Then the air pressure will increase. It will clear for a day or two, and then sunny weather will prevail as the high-pressure system passes by. Location C will have clear weather for the next day or so as a high-pressure system passes.

6. If the pressure is decreasing, it means a low-pressure system is arriving. One would expect the skies to become cloudy with some precipitation. Depending on one’s location relative to the center of the low-pressure system, one may or may not experience the more heavy precipitation associated with the fronts.

7. Answers will vary, but students should recognize that weather is important to their daily lives; weather maps are present in newspapers, Web sites, and on TV. Being able to understand weather maps helps them understand the weather and what is happening around them.

Lesson Quiz A (page 44)Multiple Choice 1. A

2. C

3. A

4. B

5. A

6. B

7. B

Lesson Quiz B (page 45)Completion 1. maritime polar

2. stationary

3. mature

4. maritime tropical

Short Answer 5. Air moves toward the low-pressure area in a

low-pressure system.

6. Because of its location and because it is a peninsula landform, hurricanes often pose severe weather threats to Florida.

7. A warning is issued when severe weather already exists. Therefore, in this particular case, a thunderstorm warning indicates that you should immediately seek cover.

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Answers continuedLesson 3Launch Lab (page 47) 1. Possible answers might include difficulty with

measurement units such as millibars, Celsius degrees, or relative humidity.

2. Weather reports cover much of the data collected and are given to help the listener predict outside conditions for daily activities.

3. Temperature: thermometer; air pressure: barometer; humidity: psychrometer or hygrometer; wind speed: anemometer; wind direction: vane; precipitation: rain gauge; cloud cover: human sight (no instrument)

4. Meteorologists collect the data from local instruments (either physically or remotely) or use data collected by a weather service.

Content Vocabulary (page 48) 1. Doppler radar

2. isobars

3. computer models

4. surface report

5. upper-air report

MiniLab (page 50) 1. The left model is completely overcast with

light snowfall and a north wind. The temperature is 28°F with a dewpoint of 20°F. The barometer is steady at 977.5 millibars (mb). The right model is sunny and dry with a southwest wind. The temperature is 72°F with a dewpoint of 58°F. The barometer is 1034.2 mb and has risen 1.0 mb in the last hour.

2. A station model is a quick and precise means of reporting conditions for a particular site.

3. The air temperature, air pressure, and humidity describe the kind of air mass covering the site. Cloud cover suggests the proximity to a front and possible weather changes. Wind speed and direction tell the direction an air mass is moving and possibly the direction from which a front will approach.

Content Practice A (page 51) 1–2. (in either order) surface reports, upper-air

reports

3. satellite images

4. radar images

5. Doppler

6–7. (in either order) visible, infrared

8. a prediction about what the weather will be like in a certain place at a certain time

9. Possible answer: They show what weather will be like in different places at different times.

10. Possible answer: Computers quickly analyze a lot of information to make a prediction.

Content Practice B (page 52) 1. 70°F

2. Possible answer: It is warm and humid.

3. It has risen two units.

4. Possible answer: High pressure is moving in, and the skies might clear.

5. Possible answer: There might be a warm front moving through the area, so it should remain warm.

6. Possible answer: pressure bars, areas of low and high pressure, more temperatures, warm front symbols

7. Possible answer: The computer model would quickly analyze temperatures, wind direction, areas of high- and low-pressure, humidity, precipitation amounts, and cloud coverage to make short- and long-term weather predictions.

School to Home (page 53) 2. Answers will vary but should show an

understanding of the relationship between the collected data and the upcoming weather.

3. Answers will vary.

4. Possible answer: Most of my predictions were correct. I recognized the front on the first day was likely to cause significant rainfall. My predictions for the second day were incorrect. I thought the rain would pass through quickly after the cold front arrived. I did not take into account the warm temperatures over the ocean waters, and this caused the front to stall rather than allowing the front to pass through.

Key Concept Builder (page 54) 1–6. (in any order) air temperature: Rising or

cooling temperatures indicate a changing weather pattern. air pressure: Changes in air pressure can indicate clear skies or the possibility of rain, depending on whether the air pressure is rising or falling. humidity: High humidity indicates the possibility of precipitation. precipitation: The amount of precipitation indicates how severe the storm is. wind speed: An increase in wind speed indicates a changing weather pattern. wind direction: Changes in wind direction could indicate a front moving into the area.

7. Cloud shape and visibility are observed by humans.

8–10. (in any order) air temperature, wind, humidity

11. A radiosonde is a package of weather instruments carried many kilometers above the ground in a weather balloon.

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Answers continued 12. A radiosonde is used to measure atmospheric

conditions.

Key Concept Builder (page 55) 1. E

2. C

3. A

4. I

5. H

6. B

7. I

8. D

9. H

10. F

11. A

12. B

13. F

14. G

15. B

Key Concept Builder (page 56) 1. warm, cold

2. low

3. The numbers decrease in low-pressure areas and increase in high-pressure areas.

4. over the ocean and in northern Canada

5. where there is low pressure

6. Possible answer: It can help predict a change in temperature, an increase in wind, and the possibility of precipitation.

Key Concept Builder (page 57) 1. Students should draw lines in the oval area

marked “HIGH.”

2. Students should draw hash marks in the area marked “LOW” and the area numbered 996.

3. Students should draw arrows pointing south behind the warm front (noted by semicircles).

4. Students should draw arrows pointing south and southeast behind the cold front (noted by triangles).

5. Students should draw arrows showing circular winds.

6. Possible answer: High pressure in the West will bring clear skies and pleasant temperatures. An area of low pressure in the upper Midwest will bring periods of precipitation. Look for continued showers in the Southeast where a cold front and warm front will continue to collide.

Enrichment (page 58) 1. Possible answer: A weather system and a flock

of migrating geese would differ in speed, altitude, magnitude, movement pattern, or intensity of the reflected echo.

2. Regular radar reflects off of everything reflective, such as fences, light posts, bridges, and other cars, whether they are moving or parked. To catch a speeder, police have to eliminate everything but the moving target and determine its speed, which is what Doppler radar does best.

Challenge (page 59)For completed chart, see page T17. Lesson Quiz A (page 60)Multiple Choice 1. B

2. A

3. C

4. C

True or False 5. F

6. T

7. F

8. T

9. T

10. F

Lesson Quiz B (page 61)Completion 1. isobars

2. radiosondes

3. Doppler radar

4. weak or calm

5. human observers

Multiple Choice 6. D

7. B

8. D

9. B

Labs A and B (pages 64, 67) 9. Answers will vary with results. With practice,

students may recognize trends. Cloud cover can help predict approaching or passing fronts. A cold air mass that is approaching signifies cooler temperatures in the days to come. Having access to other weather information, such as from other nearby stations, might help with predictions.

10. Answers will vary. Look for answers that are related to data and pattern recognition.

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Answers continuedSample answer: We collected temperature, pressure, precipitation, cloud, and wind data. The pressure data allowed us to determine whether a high- or low-pressure region was coming. High-pressure regions are associated with clear weather, and low-pressure regions are associated with clouds and precipitation. The temperature allowed us to determine when fronts passed through. Warm fronts are associated with light precipitation and an increase in temperature, and cold fronts are associated with strong precipitation and a decrease in temperature. The rain and cloud data allowed us to confirm the presence of fronts and pressure systems. The wind data also demonstrates the change in pressure.

Communicate Your Results Students’ posters should state their hypotheses clearly. The graphs should have a title, and the data should support each hypothesis. The concluding statement should indicate patterns that relate to the graph. As students present their posters to the class, have them explain how they came up with their hypotheses. Also ask them if they had to revise their hypothesis as they collected more data, and have them explain to the class how they reevaluated their hypotheses. Allow time for students to ask each presenter questions about his or her findings.

B. Extension In addition to investigating other forms of data, provide students with weather data and a weather map, along with an erroneous forecast. Have students correct the forecast and identify why some of the data appeared false.

Lab C (page 68)Please note: • Students must complete Lab B before they are

assigned Lab C.

• The procedure given below is just one possibility of many.

• If you have students perform the labs they design, make sure proper safety precautions are included before allowing them to proceed.

Sample procedure:Ask a Question When a glass of liquid is sweating, where do the drops of water that form on the outside of the glass come from?

Form a Hypothesis Students’ hypotheses may vary; the following is an example: If temperatures are lowered, then clouds will form because water vapor will condense to a liquid form.

Test Your Hypothesis Testing procedures will vary, but students should present their findings in a data table as well as labeled drawings.

Analyze and Conclude Students should present an analysis of their data and some conclusion.

Chapter Key Concepts Builder (page 69)Students should work cooperatively to complete the activity. Students’ weather map should include several weather variables such as air temperature, wind direction, and wind speed and symbols such as isobars, isotherms, cold and warm fronts, and precipitation. Maps should be accurate in how those variables are presented and be neat and interesting. Students’ weather forecasts should accurately present the information on the weather map.

Chapter Test A (page 70)Multiple Choice 1. A

2. C

3. B

4. A

5. B

6. C

7. A 8. C

Chapter Test A (page 71)Matching 9. C

10. A

11. D

12. B

Interpreting a Diagram 13. Weather fronts form when air masses meet.

14. Front A is a warm front. Front B is a cold front.

15. The cold air pushes under the warm air. The warm air is forced to rise. As it cools and condenses, clouds form.

16. In summer, a warm front brings into an area steady rain that can last for several hours or days. The picnic would most likely be rained out.

Chapter Test A (page 72)Short Answer 17. Possible answer: A major variable of weather

is rain. During the water cycle, water evaporates and enters the atmosphere. As it cools, it condenses to become visible as clouds. Clouds produce the rain associated with weather.

18. Air rises as it moves into a low-pressure system. Air sinks as it moves out of a high-pressure system.

19. Surface weather reports describe weather measurements on Earth’s surface. Weather stations report temperature, wind speed and direction, air pressure, humidity and

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Answers continuedprecipitation. Upper-air reports describe weather conditions above Earth’s surface and are measured with a radiosonde. These include wind speed, temperature, and humidity.

20. Computers are able to collect and process large volumes of weather data using mathematical models. These models help forecasters predict the weather.

Concept Application 21. Deserts are very dry. Thus, they lack enough

water vapor to produce fog even when the temperature falls below the dew point.

22. If the temperature of the air is above 0°C, rain will fall. If the temperature is below 0°C, snow, sleet, or hail will fall.

Chapter Test B (page 73)Multiple Choice 1. C

2. C

3. B

Completion 4. Weather 5. mature


7. warm front

8. barometer

9. dew point

10. lower

Chapter Test B (page 74) 11. Sleet; ice

12. tornado

13. Radiosondes; weather stations

Interpreting a Diagram 14. Both are weather fronts that form when air

masses meet. Front A is a warm front in which warm air rises as it glides upward and over the cold air mass. Front B is a cold front in which cold air moves under the warm air mass, causing the warm air to rise.

15. A warm front often brings steady rain or snow that can last for several hours or days. A warm front brings warmer, more humid weather into an area. A cold front often gives rise to severe weather and cooler temperatures.

16. If the day at the beach begins in the morning and lasts through early evening, the steady rain that will form when Front A moves in will not spoil the plans.

Chapter Test B (page 75)Short Answer 17. Possible answer: Water moves among Earth’s

geosphere and hydrosphere by changing state.

Liquid water evaporates, or changes to a gas and enters the atmosphere. As the air cools, the water vapor condenses, or changes back to a liquid, to become visible as clouds. Some clouds drop precipitation. Also, when ice or snow melt, liquid water can cycle through the water cycle.

18. Possible answer: Warm air rises over the ocean. It cools and condenses to become visible as clouds. This creates a low-pressure area. Air moves toward the low-pressure area and begins to rotate. As air continues to rise and rotate, the storm builds. When winds reach at least 120 km/h, a hurricane has formed.

19. Computers are able to collect and process more weather data than people can. Thus, computers have made weather forecasting faster, much more precise, and often more reliable.

Concept Application 20. Possible answer: Fog is common in climates

affected by maritime air masses. This is the result of large amounts of moisture in the air. Places where this occurs are coastal areas such as San Francisco, part of the Oregon coast, and New England.

21. A low-pressure system causes air to rise, cool, and condense to become visible as clouds. Often, these clouds bring precipitation in the form of rain or snow.

22. The air in the gym is colder and, thus, more dense than the air in the math classroom. Colder air holds less water vapor than the same volume of warmer air. Thus, the math classroom has the higher relative humidity.

Chapter Test C (page 76)Multiple Choice 1. B

2. B

3. C

Completion 4. Maritime tropical 5. cumulus

6. Radiosondes

7. thermometer

8. 100

9. greater

10. weather

11. high

Chapter Test C (page 77)Interpreting a Diagram 12. Front A is a warm front; Front B is a cold

front. A warm front forms when less dense, warmer air moves toward colder, dense air. A

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Answers continuedcold front forms when a colder air mass moves toward a warmer air mass.

13. a. Warm air; b. Cold air; c. Cold air; d. Warm air; e. Warm air.

14. In Front A, students’ arrows should show the warm air moving upward and over the colder air. In Front B, the arrows should indicate that the cold air mass is moving toward the warm air mass, forcing the warm air aloft.

15. After a cold front has moved through an area, winds change direction, air pressure rises, air temperature decreases, and relative humidity decreases.

16. If Front A lingered over the area, a blanket of clouds would form and likely drop steady snow that could continue for hours or days. The front would also cause temperatures to become warmer and cause winds to shift.

Short Answer 17. Possible answer: All three processes move

water among various parts of Earth via the water cycle. Most evaporation on Earth takes place over the oceans. As the air rises and cools, the water vapor in it condenses to become visible as clouds that often produce various types of precipitation.

Chapter Test C (page 78) 18. Both systems form as the result of differences

in air pressure. In a low-pressure system, air

circulates counterclockwise toward the center of the system. This forces air to rise and clouds to form. In a high-pressure system, air circulates clockwise outward from the center of the system. This creates clear skies and fair weather.

19. Computer models are detailed computer programs that solve complex mathematical formulas relating to weather and short-term changes in weather. Computers have made weather forecasting much faster, much more precise, and more reliable.

Concept Application 20. Students should be able to infer that most

tornadoes occur in the spring. This is because cool, dry air masses from Canada converge with warm, moist air masses from the Gulf of Mexico. The fronts that form cause thunderstorms, which can spawn tornadoes.

21. The air right near the beaker cooled to its dew point, causing the water vapor in the air to condense on the outside of the beaker.

22. Most pictures of the fog-shrouded bridge are taken in the early morning when the warm temperature of the air over the bay interacts with the cooler ground and the bridge itself. The temperature of the air cools and falls below its dew point. This causes water to condense and form fog.

T16 Weather

Charts and TablesContent Practice A (page 13)

Question Rain Sleet Snow Hail

What form is the water in when it is in the clouds?

liquid liquid and solid

liquid solid

What is the air temperature near the clouds? warm warm warm cold

What is the air temperature near Earth’s surface? warm cold cold warm

What is the form of precipitation that falls? liquid solid solid solid


Possible answer: They are different forms of precipitation that move water from the atmosphere to Earth’s surface.


Possible answer: Temperature determines whether water falls in liquid or solid form.


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Answers continuedKey Concept Builder (page 38)

Front

Weather Event Cold Warm Stationary Occluded

1. A colder air mass moves toward a warmer air mass. ✓

2. An approaching front stalls. ✓

3. Warm air glides above a cold air mass. ✓

4. A fast-moving cold front catches up with a slow-moving warm front.

✓

5. The boundary between two air masses stalls. ✓

6. The wind becomes gusty and changes directions. ✓ ✓

7. A wide blanket of clouds is created. ✓ ✓ ✓

8. A few days of warm weather occur. ✓

9. Warm air is forced to rise. ✓

10. This is present at the edge of an approaching air mass.

✓ ✓

11. This front moves faster than a warm front. ✓

12. This usually brings precipitation. ✓ ✓ ✓ ✓

Challenge (page 59)

°F °F (mental conversion) °C

32 0

122 122 50

212 100

98 37

64 64 18

212 212 100

5 −15

32 32 0

Weather T17


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Chapter Resources for Differentiated Instruction Weatherog-science.wikispaces.com/file/view/Lesson+1+Variable… · · 2013-02-07Chapter Resources for Differentiated Instruction