News9 Weather In the Classroom '09
Transcript of News9 Weather In the Classroom '09
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Intro to Basic WeatherUnderstanding
LAYERS OF THE ATMOSPHERE
WATER CYCLE
BASIC AIR PRESSURE
INTRO TO WEATHER BASIC UNDERSTANDING
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TO BEST UNDERSTAND HOW THE WEATHER
WORKS, YOU MUST FIRST UNDERSTAND
HOW THE ATMOSPHERE (THE THIN
LAYER OF AIR THAT SURROUNDS
OUR PLANET) IS STRUCTURED.
As we will see as we begin to
study weather more in detail,
the sun is the driving force
behind all of our weather. If the
sun were to go away suddenly,
we would not be able to live on
our planet and the weather as we
know it would cease.
Look over the diagram on the next
page and note how the atmospheric
temperature changes as you go up. Notice
that the atmosphere extends over 80 miles
up from the surface, but very little air is foundonce you go up just a few miles up. The air
gradually thins out so much that eventually
you are in outer space, where there are no air
molecules.
Then look at the water cycle on the
following page. Notice how water
continually moves about in a cycle. Pick a
starting point and follow the life of a drop
of water as it moves through the air, clouds
and ground. Notice that this cycle is on-
going at all points, meaning there is always
some water in the air, always some water in
the clouds, always some water in the rivers
and oceans, etc.
Finally, read over the section on air pressure and
youll be set with the basics that you will need to
understand how much of the weather happens!
WeatherThe Basics
INTRO TO WEATHER BASIC UNDERSTANDING
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-100 -80 -60 -40 -20 0 20 40 60
Temperature( C) shown as a dotted line on the chart above
Layers of the AtmosphereMILES
STRATOPAUSE
SHUTTLES
TROPOPAUSE
INTRO TO WEATHER BASIC UNDERSTANDING
MESOPAUSE
MESOSPHERE
STRATOSPHERE
TROPOSPHERE
THERMOSPHERE
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The Water Cycle
INTRO TO WEATHER BASIC UNDERSTANDING
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Layers of the Atmosphereand the Water Cycle
REVIEW
1 In what layer of the atmosphere do the temperatures get the warmest? ______________________________________________
2 What layer of the atmosphere is closest to the ground? ___________________________________________________________________
3 As water evaporates from the surface and begins to lift up into cooler air, what process happens that
turns that moisture into clouds?
_____________________________________________________________________________________________________________________________________________________________________________________________________________________
4 When water does not runoff into lakes and rivers, it soaks into the soil into what we call _ _ _ _ _ _ _ _ _ _ _ _water.
5 When the clouds grow in size, they produce _________________________ which brings moisture from the
air back down to the ground.
6 In the stratosphere there is a layer of ozone, a gas that absorbs incoming solar radiation.
This makes the temperature go up in the stratosphere. When you get to the mesosphere, what happens
to the temperatures as you go up in height?
_____________________________________________________________________________________________________________________________________________________________________________________________________________________
7 In what layer does most weather occur? _______________________________________________________________________________________
8Water that is given off by trees in the water cycle is known as _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
9 In what part of the atmosphere do most meteors burn up? _______________________________________________________________
INTRO TO WEATHER BASIC UNDERSTANDING
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REVIEW
1 If you are on top of a mountain, would the pressure of the air be heavier or lighter than on the beach? _____
2 Would you have more or less oxygen up in the mountains than on the beach? ____________________________________
3 What causes so much air to cluster near the ground? _____________________________________________________________________
Understanding Air Pressure
INTRO TO WEATHER BASIC UNDERSTANDING
AIRBECOM
ESTHINNERWITHHEIGHT
AIR PRESSURE IS THE WEIGHT OF AIR
ON AN OBJECT. That means you are
adding up all of the air molecules on top of
something. If you are standing on the beach
(at sea level) there is approximately 14.7 lbs.
of air sitting on top of every inch of your
body. That means on top of your head thereis over 400 lbs. of air!
Size of your head* is approximately 30
square inches
Weight of air at sea level is 14.7 lbs per
square inch.
(30x 14.7 = 441 lbs on top of your head!)
Consider the clustering of air molecules
near the surface of the Earth. They arepulled down by gravity. As you go up in the
atmosphere, the air is thinner and fewer
molecules are present.
*Average size of a childs head at age 10.
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Weather
Patterns
WEATHER PATTERNS
WEATHER VARIABLES
PRECIPITATION
SEASONS
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How Can You Measure Temperature?We use a thermometer to measure temperature. There are
several different types of thermometers. Some are made of
glass and mercury, others are digital, while others look like
a dial. How can all of these measure temperature? Well,
everything reacts to temperature changes. When it gets hot
outside, your body can sense it. Also, when it gets hot
metal expands. Mercury, a liquid metal, does this as wellWhen it gets cold outside, your body can feel it, water can
freeze, metal contracts and so does mercury.
So many different types of material
can be used in a thermometer to
measure its reaction to
temperature. Since these
different materials react to
hot and cold air, we can
measure the changes in
them and figure out thetemperature! That is how
a thermometer works.
EXPERIMENT: (Note to teachers: although many filled-glass thermometers
are filled with mercury, we strongly recommend to not use mercury thermometers in
the classroom to ensure safety. Instead, do the experiment using alcohol-filled glass thermometers.)
1 Take an alcohol filled thermometer and look at where the level of alcohol is.
2 ...Now where is the level of alcohol?____________________________________________________________________________________________________________________________________________
3 Where is the final level of alcohol?________________________________________________________________________________________________________________________________________________
Why did the alcohol move inside the tube?______________________________________________________________________________________________________________________________
______________________________________________________________________________________________________________________________________________
What liquid other than alcohol would change its size because of the temperature?
______________________________________________________________________________________________________________________________________________
What is Temperature?TEMPERATURE IS THE WAY WE
MEASURE THE AMOUNT OF HEAT WE CAN
FEEL.Actually, temperature is a measure of
the speed of tiny particles in the air.
Everything is made up of very tiny objects
called molecules. These molecules move
around. The hotter it is, the faster they move,
and the higher the temperature. So,temperature is really just a measure of how
fast these little molecules are moving
around. The amazing thing is, temperature
not only is a measure of how fast molecules
are moving, it also relates to how we feel.
As the temperature gets colder and colder,
the molecules move slower and slower. In
theory, at some point the molecules stop
moving altogether. It cannot get any colder
than this. This temperature is known as
absolute zero. Although the word zero isused, the temperature in Fahrenheit (F) is
-459F and in Celsius is 273C.
WEATHER PATTERNS TEMPERATURE
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YOU SEE THEM ALL OF THE
TIMEUP IN THE SKY.
Sometimes they are flat. Sometimes they are
puffy. Sometimes they are white. Sometimes they
are gray. Sometimes they are big and tall. They
are clouds. Clouds are made up of water droplets
or ice crystals. They appear to hang in the sky, but
they are actually just resting on the air below
them.
So what is a cloud, really? Well, first we have to
know what is in the air. Air is made up of gases
like nitrogen, oxygen and carbon dioxide. Air is
also made up of water. Not liquid water, but water
vapor. Water vapor is tiny drops of water
suspended in the air. We cannot see water vapor,
but the water is there. On humid days, there is
more water vapor in the air. On dry days, there is
not much water vapor in the air.
When air is lifted, it cools. If the air cools downenough the water vapor condenses and turns into
water droplets. These droplets are bigger than the
little pieces that make up vapor, so we can see
them. They appear to be white when the sun
shines on them. If a cloud is thick enough that
enough water droplets block out the sun, the
cloud appears grayish.
What are Clouds?
Types of clouds
CUMULUS
They are white, puffy clouds that are often flat on
the bottom. They are usually found when the
weather is nice.
STRATUS
These are low, thick, flat, grayish clouds that
usually cover the whole sky. These clouds often
are found on cool days and make it truly cloudy.
NIMBUS
These look much like stratus clouds, but nimbus
clouds have rain or snow falling from them.
CIRRUS
These are very high in the sky. They are thin andwhite and sometimes the sun can shine right
through them.
CUMULONIMBUS
This is a thunderstorm cloud. When a cumulus
cloud begins to grow taller and taller, it starts to
rain and sometimes hail, lightning, and tornadoes
can occur from cumulonimbus clouds.
WEATHER PATTERNS CLOUDS
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Identifying CloudsTry to identify the following clouds by the definitions given on the previous page.
Write your answers below each picture.
WEATHER PATTERNS CLOUDS
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DIRECTIONS
Tape the black paper to the outside of the jar so that it only
covers half of the jar. You should be able to look through one
side of the jar and see the black paper on the other side
(Make sure the paper does not touch the bottom of the jar)
1 Put two cups of hot water into the jar.
2 Make certain that the water is hot enough to make the
air inside the jar very hot and humid.
3 Place nylon over mouth of jar and secure with the rubber band
4 Place ice cubes on top of the nylon and watch the cloud
develop right below the nylon inside the jar.
(You may need to peel back the nylon to let the
cloud escape to see better.)
Note: This experiment can also be done by covering the
jar with an aluminum pie plate in place of the nylon and
rubber band. In that form, you would place the ice on
top of the aluminum pie plate.
MATERIALS
1 large, large-mouthed glass jar
1 rubber band
1 piece of nylon (to cover jar mouth)
2 cups of warm water
5 ice cubes
1 piece of black paper
Tape
LESSON
What have you done?The warm, humid air in the jar represents the warm water near the
earths surface. As it rises, the air around it cools (that is what the
ice on the nylon represents). As the warm, humid air is cooled
by the cold air above it, it forms a cloud in the jar!
Making a Cloud
WEATHER PATTERNS EXPERIMENT MAKING A CLOUD
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WHENEVER A CLOUD IS FULL OF DROPLETS OR ICE CRYSTALS, THEY CAN
GROW TO BECOME TOO LARGE TO REMAIN IN THE CLOUD. They start growing
by sticking to a dust particle or a small piece of suspended material in the air. More
and more droplets or crystals stick to it until it is too heavy to remain in the cloud
and the droplet or collection of crystals begins to fall. This is called precipitation.
If the precipitation that falls is a large droplet (water), then it is called rain. Water
freezes at 0C (32F). So, if the air in the cloud is very cold, then a large collection
of ice crystals may form into a flake and fall as snow. There are several other types
of precipitation, as well. If a raindrop falls from a warm cloud through some very
cold air and it freezes, then it becomes sleet. Sleet is a raindrop that froze on the
way down to the ground and hits the ground in the form of an ice pellet. Another
type of precipitation is freezing rain. Freezing rain is a raindrop that is just about
to freeze on the fall to the ground. It looks like rain, but coats everything it hits in
ice. It can form an icy glaze on roads, cars, trees, etc.
REVIEW
Now that you know so much about rain, sleet, freezing rain, and snowsee if you cananswer the following questions:
1 What season would you most likely find freezing rain, sleet and snow? ________________________________________________________
2 If a snowflake fell and melted on the way to the ground, what type of precipitation would it be?
_____________________________________________________________________________________________________________________________________________________________________________________________________________________
3 What if that snowflake melted on the way down, but then re-froze just before hitting the ground.
What type of precipitation is that? ___________________________________________________________________________________________________________________
4 Can you have rain and snow falling at the same time?___________________________________________________________________________________
BONUS Why or why not?______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
The Sky is Falling!
WEATHER PATTERNS R AI N, S LE ET, A ND S NO W
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DIRECTIONS
1 Using the ruler and paper, make markings on the paper so
that it becomes a ruler. You can make it in whateverincrements you wish. Divide it up by inch, and then in
quarters, and even smaller if you want to.
2 Once you have the ruler made, cut it out.
3 Cover the ruler with clear cellophane, front and back. This
will protect it from the rain, and make it sturdy so that the
ruler can stand straight.
4 Stand the ruler inside the container so that the ruler
rests on the bottom of the container. Tape it at the top, tothe inside of the jar, so that the ruler does not fall.
5 Place your rain gauge outside, and measure the amount of
rainfall that occurs each day. Place the rain gauge in a
place away from trees and buildings, as this may affect the
amounts. Also, you may wish to glue the jar to a block o
platform of wood, so that it does not tip over if it is windy.
MATERIALS
1 straight-side clear plastic container
(curved sides would skew the rain totals)
scissors
clear cellophane orplastic sandwich bag
tape
rainy days
graph paper
plain paper
ruler
Rain clouds are made of droplets of water so small that there are billions of them in a single cloud. How much
rain falls during a shower, or during a day, week, or month? You can find out by measuring it with a rain gauge.
RECORD RESULTSRecord the amount of rain you receive every time it rains on your graph paper and compare that to the amount
recorded at the nearest official rain gauge. (You may want to record the official rain total on the same graphpaper in a different color.) You can see some of the states official amounts on the website: (note that the daily
amount is updated a couple times per day, but the official amount is not recorded for that day until just after
midnight, so it may be best to compare the amounts on the next day)
Once on the website for Weather in the Classroom, (web link can be found on the front cover),
simply follow the links for Daily Weather and Climate Data.
Making a Rain Gauge
WEATHER PATTERNS EXPERIMENT MAKING A RA IN GAUGE
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IN ORDER TO UNDERSTAND THE SEASONS, YOU NEED TO FIRST UNDERSTAND HOW THE EARTH
REVOLVES AROUND THE SUN ONCE PER YEAR. Look at the picture below showing the Earth at different
positions in space during the year.
In this graphic, the thick, solid line
shows you where the north and
south poles are. Notice that
the Earth is tilted, that is to
say that it does not have
the North Pole at the
very top and the
South Pole at the
very bottom.
The Earth revolves
around the sun once
each year. Near
December 21st, the
South Pole is facingtoward the sun and the
North Pole is facing away
from the sun. This gives the
Northern Hemisphere (where we
live) shorter days and less direct
sunshine. This makes our weather colder and
we call this season WINTER.
Then the Earth moves so that the sun shines directly over the Equator by March 20th. The Equator is a line that
marks the halfway point between the North and South Poles. When the sun shines directly over this line, the
days and nights are nearly of equal length. The season changes at this point and we call it SPRING.
The Earth then moves around the sun so that the North Pole is facing the sun. The daylight becomes longe
for the Northern Hemisphere and the sunlight more direct. By June 21st, the sun is at its strongest for the
Northern Hemisphere and the temperatures warm up. We call this season SUMMER.
The Earth continues to revolve around the sun. By September 22nd, the sun is once again over the Equator.
The days and nights are again nearly equal length. The Northern Hemisphere is cooling down and we begin a
season calledAUTUMN or FALL.
WEATHER PATTERNS SEASONS
Understanding Seasons
Jun. 21st
Sept. 22nd
Dec. 21st
Mar. 20th
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What to Expect in Oklahoma
Read the following descriptions of what to expect with each season in Oklahoma:
WINTER Days are short, nights are long
Sun is lower in the sky
Sun is directly over the
Southern Hemisphere
Temperatures are colder
Rain, ice or snow can fall
Temperatures change often
Most trees have no leaves on them
Strong winds can produce
dangerously cold wind chills
SPRING
Days and nights are equal length at
the beginning of Spring
Days get gradually longer through
the season
Sun is directly over the Equator onthe first day of Spring
Flowers bloom and trees produce
new leaves
Temperatures gradually warm up
Rain and thunderstorms are frequent
Temperature changes often
WEATHER PATTERNS SEASONS
FALL
Days and nights are equal length atthe beginning of Fall
Days get gradually shorter through
the season
Sun is directly over the Equator on
the first day of Fall
Leaves begin to change colors and
fall from the trees
Temperatures gradually cool down
Rain and thunderstorms
occassionally occur
Temperature changes often
SUMMER
Days are long, nights are short
Sun is higher in the sky
Sun is directly over the Northern
Hemisphere
Temperatures are hotter
Plants grow all season
Thunderstorms occasionally happen
during the afternoons and can
produce heavy rain
Temperatures do not change much
day to day
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Use the previous pages on the seasons to answer the following questions:
1 What would the season be on April 20th? ___________________________________________________________________________________
2 On the first day of which season is the sun directly overhead the Northern Hemisphere? ____________________
3 In which season would you expect to see the most sleet? _____________________________________________________________
4 What season are the days the longest? ______________________________________________________________________________________
5 Complete the following picture by shading the side of Earth that would be dark. From this drawing,
figure out which season it is.
What season is it in the picture above? ___________________________________________________________________________________________
Questions about the Seasons
WEATHER PATTERNS QUESTIONS SEASONS
NORTH POLE
SOUTH POLE
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WATER IS PLENTIFUL ON
EARTH. It covers nearly two-
thirds of the surface of our planet.
But water is also commonly found in large quantities
in the air. You can see the effect of the suspended
water droplets in the atmosphere. Rainbows, clouds,
hazy skies, and even fog are all ways we can visiblysee the water droplets suspended in the air. However,
even when it seems as though we cannot see the
water in the air, it is still there. Sometimes there is little
water present and the air is dry. At other times there is
a lot of water in the atmosphere and we say that it is
humid. These are ways to describe the humidity.
Humidity is often misunderstood. Relative humidity is
different for every temperature. Why? Because relative
humidity is a percentage showing how much water is
in the air compared to how much water the air could
hold at that temperature. So if the temperaturechanges, so does the relative humidity. Warm air can
suspend more water than cold air. So, if the amount of
water doesnt change, then the relative humidity
would go down when it gets warmer (because the air
could hold more at that temperature) and the relative
humidity would go up if gets colder (since the air
cannot hold as much water when cold). If the relative
humidity is 50%, then you are really saying that the air
has half of the amount of water it could hold at that
temperature. If the humidity is 100%, then the
atmosphere cannot hold any more water. At that point,fog may form or dew may form on surfaces.
Keep in mind, since relative
humidity is dependent on
temperature, you cannot comparehumidity from one place to another
or from one time to another unless the
temperatures are the same. For
example, 100% humidity at 45 degrees
actually has less water in the air than 75%
humidity at 80 degrees. It may sound
confusing, but we have another way to
help us compare humidities. Remember
that dew may form when the humidity is
100% because the air cannot hold any
more water. So, if you can figure out when
dew will form, then you know how muchwater you have in the air. This is called the
dew point temperature.
To find the dew point you need to take
the air you currently have and cool it
down without losing any of the water in
the air. As you cool the air, the
humidity will rise. When the humidity
rises to 100%, you have reached the
dew point. Now you can compare
dew points from one place to another as a goomeasure of the amount of moisture in the air.
INTERESTING NOTE: Sometimes people will exaggerate about the relative humidity. It is common for
people on a hot, humid summer day to say that the temperature and humidity are high. However some people
will say that it is 95 degrees and 100% humidity. This could never happen on Earth. That would make the dew
point 95 degrees, too, since the humidity is 100%. Dew points rarely go higher than 80, and we could not
physically handle dew points into the 90s on Earth for very long.
WEATHER PATTERNS HUMID ITY
What is Humidity?
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DIRECTIONS
1 Outside on a warm, humid day in the spring or
summer, put a couple of inches of warm (about 75F)
water in a cup.
2 Measure the temperature of the water. Now add a few
drops of ice cold water to your cup.
3 While you are adding water, keep stirring and
measuring the temperature of the water.
4 Repeat this procedure by adding a small amount of
cold water to the cup until you see a thin film of water
form on the outside of the cup.
5 Make a note of the temperature of the water as soon
as you see the water vapor form on the outside of the
cup.
The temperature you measured is the DEW POINT!
MATERIALS
a thin metal cup or a drinking glass(not thermal)
thermometer
ice water
a large dropper(a measuring cup with a pour spout will do)
LESSON
What happened?As you added colder water to the warm water in
the cup, the temperature of the water in the cup
kept dropping. The sides of the cup got colder
as the water inside got colder. The cup also
chilled the air right next to it! When the
temperature of the metal cup reached the dew
point... The air just next to the cup was cooled
to the dew point as well and water began to
condense from the air and stick to the cup!
REVIEW1 What was the temperature of the water when you started your experiment?
_____________________________________________________________________________________________________________________________________________________________________________________________________________________
2 What was the temperature of the water when you saw the condensation form on the outside of the cup?
_____________________________________________________________________________________________________________________________________________________________________________________________________________________
3 Would your cup of water have to be colder or warmer to reach the dew point if the air outside is very dry?
_____________________________________________________________________________________________________________________________________________________________________________________________________________________
Measuring HumidityHow you can measure the dew point.
WEATHER PATTERNS EXPERIMENT MEASURING HUMID ITY
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DIRECTIONS
1 In one can, place several ice cubes.
2 In a separate can place a mixture of ice cubes and rock salt.
3 Wait a few moments and notice what happened to the two cans.
MATERIALS
2 metal cans
rock salt
ice cubes
thermometer
LESSON
What have you done?The can with ice and salt will be colder.
The reason for this is saltwater has a
lower freezing point than pure water (the
same reason salt is applied to roadways
in winter). This lower freezing point
allowed for more water to evaporate and
more evaporative cooling of the saltwater
in the can. Thus, the final temperaturewas colder of the saltwater can.
REVIEW1 Which of the cans had the frost form on the outside?
_________________________________________________________________________________________________________________________
2 Which of the cans had dew form?
_________________________________________________________________________________________________________________________
3 What was the temperature of the two cans?
_________________________________________________________________________________________________________________________
4 What made one can colder than the other?
_________________________________________________________________________________________________________________________
Dew and Frost
Recall that dew forms when the humidity reaches 100% and the atmosphere can no longer hold any more
water. Some of the water is deposited on surfaces as dew. This happens when the temperatures are above
freezing. When the temperatures fall below freezing when the humidity hits 100%, something else forms.
Instead of droplets of water forming on the grass and on car windshields, we see ice crystals forming on
surfaces. This is called frost.
Demonstrating Frost & Dew in the Classroom
NOTE: During the winter months, the air can become very dry (especially on cold days) and it may be difficult
to cool the cans down to the dew point temperature. On a very dry day, you may see only frost form on the
colder can, but no dew. If this is the case, wait and try again on day when the dew point is higher (more moisture
in the air). You can find the dew point temperature by following weather observations online.
WEATHER PATTERNS EXPERIMENT DEMOSTRATING DEW AND FROST
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Recording the Weather
Use the Recording the Weather DATA CHART to fill inthe weather information for one week.
DIRECTIONS
1 Pick a city in Oklahoma and log on to the Weather in the Classroom website.
You can find the link for the website on the front cover of this booklet.
You will then be able to select Current Weather for the following areas of the state:
Eastern Oklahoma
Central and Western Oklahoma
2 Click on the city on the map you have chosen to see the current conditions.
3 Record the temperature, wind direction, wind speed, air pressure,
current weather type and relative humidity.
4 Do this at the beginning of the school day, the middle of the day and again at the end of the day.
5 Write down any interesting things that happened with the weather on the Recording the Weather
INFORMATION PAGE. Be sure to include big changes from sunny skies to cloudy skies or when
precipitation started to fall.
6 When you have finished recording the weather for the week, answer the questions on the
Recording the Weather QUESTION SHEET.
WEATHER PATTERNS EXPERIMENT RECORDING THE WEATHER
Oklahoma Panhandle
Extreme Southeastern Oklahoma
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TEMPERATUREWIND
DIRECTIONWIND SPEED
RELATIVE
HUMIDITYAIR PRESSURE
SKY
CONDITION
MONDAY
Morning
Midday
Afternoon
TUESDAY
Morning
Midday
Afternoon
WEDNESDAY
Morning
Midday
Afternoon
THURSDAY
Morning
Midday
Afternoon
FRIDAY
Morning
Midday
Afternoon
Weather Data Chart
WEATHER PATTERNS EXPERIMENT RECORDING THE WEATHER
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Information PageOBSERVATIONS
MONDAY:
Were there clouds today? ___________________________________________________________________________________________________________
Was there any precipitation? _______________________________________________________________________________________________________
*Describe the weather for the day? ______________________________________________________________________________________________
TUESDAY:
Were there clouds today? ___________________________________________________________________________________________________________
Was there any precipitation? _______________________________________________________________________________________________________
Describe the weather for the day? _______________________________________________________________________________________________
WEDNESDAY:
Were there clouds today? _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Was there any precipitation? _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Describe the weather for the day? _______________________________________________________________________________________________
THURSDAY:
Were there clouds today? ___________________________________________________________________________________________________________
Was there any precipitation? _______________________________________________________________________________________________________
Describe the weather for the day? _______________________________________________________________________________________________
FRIDAY:
Were there clouds today? ___________________________________________________________________________________________________________
Was there any precipitation? _______________________________________________________________________________________________________
Describe the weather for the day? _______________________________________________________________________________________________
* Weather might include partly cloudy, fog, rain, snow, sunny, windy, breezy, cold, warm, hot, etc.
WEATHER PATTERNS EXPERIMENT RECORDING THE WEATHER
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Question SheetAfter recording weather conditions for the week, look over the weather data youcollected and answer the following questions:
1 What time of day did you notice the coolest temperatures?
a. Morning b. Midday c. Afternoon
2 What time of day did you notice the highest temperatures?
a. Morning b. Midday c. Afternoon
3 What time of day did you notice the lowest relative humidity?
a. Morning b. Midday c. Afternoon
4 What time of day did you notice the highest relative humidity?
a. Morning b. Midday c. Afternoon
5 If there was any precipitation during the week, what happened to the humidity during that time? Why doyou think the humidity changed the way that it did? ____________________________________________________________________________________________________________
6 What was the strongest wind speed you recorded during the week? ___________________________________________________________________________
What was the weather during the time you recorded that wind speed?_______________________________________________________________________
7 Did you notice a pattern with the air pressure during the times you recorded it? Was it going up?
Was the air pressure dropping?_____________________________________________________________________________________________________________________________________________________
8 Did a change of wind direction occur during the week? If so, what were the temperatures like the day
before the wind shifted? What about the day after the wind shifted? ___________________________________________________________________________
9 Did clouds affect the temperatures for the week? (Were sunny days warmer than cloudy days?
Were cloudy days warmer than sunny days?)__________________________________________________________________________________________________________________________
10 What did you notice about the overall weather pattern for the week that lead to so many different types
of weather to occur? __________________________________________________________________________________________________________________________________________________________________________
WEATHER PATTERNS QUESTIONS RECORDING THE WEATHER
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DIRECTIONSUse the Mapping the WeatherAREA MAP to complete
the following activities:
1 Write the temperatures on the map above each citys
name.
2 Draw temperature contours for 35, 40, 45, 50, and 55
(Temperature contours are lines that connect equa
temperatures. You may need to ask an adult to help you
complete this step.)
3 Color the area below 35 in dark blue.
4 Color the area between 35-40 in light blue.
5 Color the area between 40-45 in green.
6 Color the area between 45-50 in yellow.
7 Color the area between 50-55 in orange.
8 Color the area over 55 in red.
MATERIALS
Colored pencils(dark blue, light blue, yellow, orange, green)
Mapping the Weather
TULSA: 53
MCALESTER: 51
LAWTON: 36
WOODWARD: 39
GUYMON: 29
MIAMI: 57
ARDMORE: 47
OKLAHOMA CITY: 46
DURANT: 54
STILLWATER: 47
PONCA CITY: 44
ALTUS: 32
IDABEL: 56
Use the following temperaturesfor your mapping:
WEATHER PATTERNS EXPERIMENT MAPPING THE WEATHER
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Mappingthe
Weathe
r
AreaMap
WEATHER PATTERNS EXPERIMENT MAPPING THE WEATHER
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Why the
Wind Blows
WHY THE WIND BLOWS
WEATHER VARIABLES
PRECIPITATION
SEASONS
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HIGH PRESSURE
High pressure is seen on a weather map as a blue capital H. Since
the pressure is high, air needs to move away from a high pressure. Near
a high pressure, the winds are usually light and circulate clockwise away
from the high. Because air is leaving the high pressure area, air from above
comes down to replace the air that left. This sinking air keeps the skies mostly
clear and free from clouds that could develop into showers or thunderstorms. Highpressure is usually associated with nice weather.
LOW PRESSURE
Low pressure is seen on a weather map as a red capital L. Since the pressure is low, air needs to fill it in, so
it moves toward the low, but around it counterclockwise at the same time. Often the winds can be quite strong
around a low pressure. Because the air is piling up at the low, some of the air is forced up. This rising air often
becomes clouds and even produces rain. If the atmosphere is unstable then the rising air can become
thunderstorms. Low pressure is often associated with stormy weather.
In the picture below, the winds are shown around areas of high and low pressure at the surface.
High Pressure & Low Pressure
WHY THE WIND BLOWS HIGH PRESSURE AND LOW PRESSURE
L H
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FRICTION IS A FORCE THAT ACTS TO SLOW DOWN THE MOVEMENT OF AN OBJECT. Ice has a very lo
amount of friction, so walking across it is very slick, but sandpaper has a high friction and you could get goo
traction walking across sandpaper.
If there were no friction at the surface of a non-rotating Earth (no trees, no grass, no hills, etc) then the win
would try to blow straight from high pressure to low pressure like this:
The Effect ofFriction
But there since the Earth is constantly rotating, the wind turns as the world turns. This is known as the
Coriolis force. So, when you have high and low pressure with a rotating Earth, but no friction, then the wind
blows like this:
But there is friction at the surface. Friction not only slows the speed of the wind, but it also changes the effec
of the spin of the Earth. This causes the winds to blow like this:
H L
H L
H L
WHY THE WIND BLOWS HIGH PRESSURE AND LOW PRESSURE
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MATERIALS
Small coffee can
Plastic wrap
Rubber band
Drinking straw
Large index card
Making a Barometer
DIRECTIONS
1 Take a small coffee can and
cover it tightly with plastic wrap.
Secure the plastic wrap with a
rubber band around the can as
shown above.
2 Tape a straw to the top of your
plastic wrap cover with one end of
the straw in the middle of the cans
cover and the other end slightly off
the edge of the can. (see right)
3 Next place the can beside a
large index card. Use this card to
mark and label where the straw is
pointing on the card. Remember to
write down the day and time beside
each mark you make. Notice the
changes on the position of the
straw during each day of the week.
Looking down at the can:
REVIEW
After recording your air pressure results for the week, answer the following questions:
1 What days had the highest pressure? ___________________________________________________________________________________________
2 What days had the lowest pressure? ____________________________________________________________________________________________
3 Why did the plastic wrap get pushed down by high pressure? __________________________________________________________
4 What interesting weather happened when the pressure was changing? ______________________________________________
LESSON
Notice that when the airpressure is high, it pushes
down on the plastic wrap
and the straw is tilted up.
When the air pressure is
low, the plastic wrap lifts
upward and the straw
points down.
Barometers are used to measure air pressure.Use the following directions to make your ownbarometer and measure changes in the air pressure.
WHY THE WIND BLOWS EXPERIMENT MAKING A BAROMETER
Plastic wrap
Rubber band
Coffee can
Straw
Coffee can
Large index
card
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DIRECTIONS
Experiment 11 Fill a large bowl with ice cold water. Set aside.
2 Fill the glass bottle with very warm to hot water.
This allows the bottle to get fairly warm, as well.
3 Empty the glass bottle and quickly cover the bottles
opening with a balloon. This traps in very warm airinside the warm bottle.
4 Now place the bottle upright in the bowl of cold
water. This will cool the air inside the bottle down.
Observe what happens to the balloon.
Write down your results.
Experiment 21 Fill a large bowl with very warm water. Set aside.
2 Fill the glass bottle with cold water. This allows the
bottle to get fairly cold, as well.
3 Empty the glass bottle and quickly cover the bottles
opening with a balloon. This traps in cold air inside
the cold bottle.
4 Now place the bottle upright in the bowl of warm
water. This will heat the air inside the bottle. Observe
what happens to the balloon. Write down your results.
MATERIALS
glass bottle
balloon
large bowl
water
LESSON
What did you learn?In Experiment 1, the air inside the bottle was
cooled. When air is cooled, it contracts and the
density is higher (more compact). Since the air
was contracting, it sucked the balloon into the
bottle.
In Experiment 2, the air inside the bottle washeated. When air is heated, it expands and the
density is lower (less compact). Since the air
was expanding, it caused the balloon to expand
outside the bottle, as well.
In the atmosphere the warmer, lighter air rises
since it is lighter, and the colder air sinks since
the density is higher. Sinking cold, air can create
areas of high pressure and rising, warm air often
creates areas of low pressure.
Balloons & Air DensityIn this experiment, you will see how air density changes when the temperatures change. Density is a measure
of the amount of mass (or amount of molecules) in a given volume. More simply, it is how compact or how
thick a substance is. So what happens when air is heated and cooled? Does it become more or less
compact? Find out and see!
WARNING: In the following experiments, avoid getting the glass bottle too hot or too cold. Temperature extremes may cause
the bottle to break.
WHY THE WIND BLOWS EXPERIMENT BALLOONS & A IR DENSITY
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TORNADOES CAN TAKE ON
SEVERAL SIZES AND SHAPES
AND SOMETIMES HAVE SEVERAL
DIFFERENT NAMES. It is important
to understand what different
tornado-related words mean and
how to use them.
A tornado (sometimes called a twister or
cyclone) is an area of rapidly circulating winds
that blow around a small, but intense, low-
pressure area. Tornadoes usually extend from the
base of a thunderstorm.
A funnel cloud is similar to a tornado, but its circulation is
in the air and has not reached the ground. At the point the
circulation reaches the ground, a funnel cloud becomes a
tornado.
A wall cloud is a lowering out of the base of a thunderstorm (even lower than the bottom of the
thunderstorm itself) which is rotating. Wall clouds are sometimes difficult to detect because of their
ragged appearance. However, wall clouds are indicators of the most dangerous part of the
thunderstorm base. It is in this area that tornadoes develop.
Why do tornadoes form?
What are Tornadoes?
WHY THE WIND BLOWS TORNADOES
Tornadoes form when conditions are right and can
even help large thunderstorms keep themselves
going. Without the tornado, many thunderstorms
would lose their source of warm, humid surface airthat keeps them alive. Large thunderstorms take large
amounts of air from the surface up into the body of
the thunderstorm. Some air must come back down
to replace the air that was sucked up into the
thunderstorm. This downward moving air is called a
downdraft. Downdrafts are necessary, but they can
choke a thunderstorm and give it no way to pull
warm, humid air up into the main body of the storm.
That is where the tornado can be helpful to a
thunderstorm. It allows a thunderstorm to take in
large amounts of air at a time into the storms body
Unfortunately, this process is very damaging to
anything in its path.
Tornadoes can have wind speeds anywhere from
near 65mph all the way up to more than 300mph
They vary in size, too. Small tornadoes may only be a
few feet wide, but large tornadoes can reach a
diameter more than one mile wide. Most tornadoes
are between 300 and 2000 feet wide. Each year in the
United States, about 1,000 tornadoes form.
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TORNADOES ARE MADE ONLY IN
CERTAIN TYPES OF WEATHER PATTERNS. This allows
meteorologists to issues forecasts and Tornado Watches to
warn you ahead of time. To make a tornado, you need the
winds to be turning as you go higher and higher up in the
atmosphere.
For example, say the wind on the ground is blowing from the southeast.
But, if you go 500 feet above the ground, the winds are blowing from the
southwest. That means that the winds are turning from the southeast to the
southwest near the ground. Also remember that the air from the ground
level feeds a thunderstorm. This air is turning already and as it is sucked
into the thunderstorm, the whole thunderstorm begins to turn, or rotate.
What happens when you take a glass of water and stir it up very fast with
a spoon? As the water in the glass rotates faster and faster, a little funnel
forms in the middle of the glass and tries to reach the bottom of the
glass. In a similar way, a thunderstorm has air rotating around the
inside of it and eventually a funnel cloud may form out of the bottomof the thunderstorm. If that funnel cloud reaches the ground it becomes a tornado!
The Invisible TornadoNOT ALL TORNADOES CAN BE SEEN CLEARLY. SOME ARE DISGUISED BY HEAVY RAIN. Some take place
at night in the dark. Some, however, are not wrapped in rain or at night, but you still cant see them! These arelike invisible tornadoes.
So how do you know that a tornado is there? First of all, remember that tornadoes form beneath rotating
thunderstorms. A tornado is a tornado if its rotating winds have touched the ground. Sometimes the funnel-
shaped cloud is not visible. At the point the tornado touches the ground, it begins to swirl dirt and debris. This
is called a debris cloud. If you see a debris cloudbut no visible tornadoyou have just spotted an invisible
tornado. These are just as dangerous as any other tornado!
WHY THE WIND BLOWS TORNADOES
Why do Tornadoes rotate anyway?
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Ranking the TornadoesTORNADOES ARE MEASURED BY THE AMOUNT OF DAMAGE THEY PRODUCE. It would be impossible fo
anyone to accurately measure a tornado the way we normally measure wind, because the tornado would
destroy the equipment. Also, tornadoes form and go away before we could get the equipment to the tornado
So, the only way left to measure them is to look at the damage they did.
We use a scale to measure the damage caused by a tornado and from that damage, we can estimate the
winds. Look at the Fujita scale below for tornadoes and the description of the damage caused. This is the new
wind damage scale that was first used in 2007.
EF-SCALE
NUMBER
INTENSITY
PHRASEWIND SPEED TYPE OF DAMAGE DONE
EF-0 Gale tornado 65-85 mph
Some damage to chimneys; breaks branches off
trees; pushes over shallow-rooted trees; damages
sign boards.
EF-1Moderate tornado 86-110 mph
The lower limit of hurricane wind speed; peels
surface off roofs; mobile homes pushed off
foundations or overturned; moving autos pushed offthe roads; attached garages may be destroyed.
EF-2Significant tornado
111-135 mph
Considerable damage. Roofs torn off frame houses;
mobile homes demolished; boxcars pushed over;
large trees snapped or uprooted; light object
missiles generated.
EF-3 Severe tornado 138-167 mph
Roof and some walls torn off well-constructed
houses; trains overturned; most trees in forests
uprooted
EF-4Devastating tornado
168-199 mph
Well-constructed houses leveled; structures with
weak foundations blown off some distance; cars
thrown and large missiles generated.
EF-5 Incredible tornadoMore than
200 mph
Strong frame houses lifted off foundations and
carried considerable distances to disintegrate;
automobile-sized missiles fly through the air in
excess of 100 meters; trees debarked; steel
reinforced concrete structures badly damaged.
WHY THE WIND BLOWS TORNADOES
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REVIEW
Use your knowledge of tornadoes to answer the following questionsto the best of your ability.
1 About how many tornadoes occur in the United States every year? __________________________________________________
2 According to the National Weather Service, Oklahoma averages around 53 tornadoes per yea
In which season of the year do you think most of these tornadoes occur?___________________________________________
3 If a framed house was hit by a tornado and the damage consisted of a roof that was torn off, windows were
blown out, but most of the walls were still standing, then what would the Fujita-scale ranking be of this
tornado? (use the chart on the previous page for assistance on this one) ____________________________________________
4 What type of cloud rotates at the bottom of a thunderstorm and is a warning sign of a possible tornado?
______________________________________________________________________________________________________________________________________________
5 What is the name of the cloud of dust and broken materials that forms at the bottom of a tornado?
______________________________________________________________________________________________________________________________________________
6 A tornado looks like it is developing from a thunderstorm. What would the name of this developing tornado
be BEFORE it reaches to the ground?___________________________________________________________________________________________
WHY THE WIND BLOWS QUESTIONS TORNADOES
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What is a Hurricane?
WHY THE WIND BLOWS HURRICANES
A HURRICANE IS A LARGE, STRONG STORM THAT DEVELOPS OVER THE WARM WATERS OF THE
OCEAN. This area of warm ocean water is known as the tropics. Hurricanes form when air moves toward an
area of low pressure over very warm water. At the low-pressure center, this air begins to rise forming a large
area of thunderstorms. If the air is allowed to evacuate from the top of the hurricane (high pressure in the
upper-levels of the atmosphere causes wind to spread out) and the storm remains over warm water, then the
hurricane will strengthen. (Note that the water off the west coast of the United States is much colder than
the waters off of the East Coast. That, along with more favorable wind patterns in the East Coast areas,
makes a land-falling West Coast hurricane a rare occurrence.)
Remember that air spins counter-clockwise around low pressure. Lets say that at the ocean surface a low
pressure begins to develop. The air begins to move in toward the low pressure and around it counterclockwise
As all of this air comes together, too much piles up in this area and some has to rise to escape. This lifting
air often develops into thunderstorms. As the pressure drops, the air spins faster and more air rises forming
more thunderstorms. This keeps going and going until the storm system is very strong. It has very fast winds
spinning counter-clockwise with bands of thunderstorm rotating around it, too. This is now a hurricane.
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SINCE HURRICANES DO SO MUCH DAMAGE, PEOPLE
OFTEN WANT TO TALK ABOUT A CERTAIN HURRICANE. The
easiest way to talk about something is if you give it a name. So,
hurricanes are named. (The same could be done for tornadoes,
but there are too many to name!)
As a storm in the tropics develops and gets stronger, it is givendifferent names. A tropical depression is a developing storm
that has maximum winds of 39mph or less. As the storm gains
strength, and reaches winds of 40mph to 73mph, it is called a
tropical storm. A tropical storm becomes a hurricane when the
maximum winds of the storm reach 74mph. Hurricanes can
have wind gusts more than 200mph.
Each year, there is a list of names that will be given to hurricanes
or tropical storms in the order that they occur. The first named
storm gets an A name, the second a B name, and so on. The
name list alternates mens and womens names through the list
and each ocean has its own set of names. Hurricanes are alsoranked into categories by strength on the Saffir-Simpson Scale.
WIND SPEEDS
CATEGORY 1 74-95 mph
CATEGORY 2 96-110 mph
CATEGORY 3 111-130 mph
CATEGORY 4 131-155 mph
CATEGORY 5 156 mph or more
Where Most TropicalSystems Form
Naming the Hurricanes
WHY THE WIND BLOWS HURRICANES
PACIFIC BASIN
ATLANTIC BASIN
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WHY THE WIND BLOWS QUESTIONS HURRICANES
REVIEW
Answer the following questions from what you have learned in the previous pagesand in class about hurricanes.
1 Residents of North Carolina watch which ocean for developing hurricanes and tropical storms?
______________________________________________________________________________________________________________________________________________
2 Why would you not be concerned about a hurricane hitting San Francisco,
even though it sits right on the coast? ___________________________________________________________________________________________
______________________________________________________________________________________________________________________________________________
3 Look up the link on hurricane names at the Weather in the Classroom website (see front cover for
web address) and fill in the names for this years hurricane season.
4 Put the following tropical systems in order from weakest to strongest: Hurricane,
tropical depression and tropical storm.
Weakest _________________
_________________
Strongest _________________
A Name_______________________________
B Name_______________________________
C Name_______________________________
D Name_______________________________
E Name_______________________________
F Name_______________________________
G Name_______________________________
H Name_______________________________
I Name_______________________________
J Name_______________________________
K Name_______________________________
L Name_______________________________
M Name_______________________________
N Name_______________________________
O Name_______________________________
P Name_______________________________
R Name_______________________________
S Name_______________________________
T Name_______________________________
V Name_______________________________
W Name_______________________________
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AUTUMN HEATWAVE SNOWFLAKE THUNDERSTORM
BLIZZARD HURRICANE SPRING TORNADO
BREEZY LIGHTNING SUMMER WINDY
HAILSTORM SEVERE THUNDER WINTER
J O X P C S H R R V N M U T U A D T J N
R K U H O O E A N E R D R A Z Z I L B E
D N Y U V D C P I O X S N O W F L A K E
K V F Y N V Y V T L I H Z O U S O Q L H
E Q Y U B A X S O Y S H K D Z P C I O WW V H H B S R J O W U T P A Z R B K B T
S T A B R E U J N R S S O N V I A Y Z Y
Y P E W D L N M R Z X A V R A N F A J F
M V A N T X J I M E F B C O M G A U V E
W S U R Z A C B R E E Z Y T W L K D O J
R H P L S A E L X B R T C I Y I J Y M E
T U O C N D M H W M K R N Y O G V M Q N
U F N E R X K V I O Q T R D N H B G T S
E G T J V R M K J D E E H N X T D J J W
W R N D I K O M H R Y W B I F N O H G N
B K E B V F E K W X U S D W C I P L N K
Q L E V N D Y Z I G S V F H V N T S Y N
Y L A V E Q V Y D Z G K U E I G L E M J
V V N K H S Y D E N Z B K C U G K U Q B
A A V C O S E Z D F F Q J P F J B E U V
Weather Word Search
WHY THE WIND BLOWS GAMES WEATHER WORD SEARCH
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Meteorology Crossword
ACROSS
7. The measure of how much mass
(weight) is in a given volume.
9. A high, thin cloud made up of
ice crystals.
11. Used to measure air pressure.
13. Used to measure air temperature.
14. This is violently rotating column of air.
15. The wind flows clockwise around
an area of ______ pressure.
16. Frozen drops of rain that fall as
pellets of ice in winter.
DOWN
1. The scale by which we
categorize hurricanes.
2. A type of cloud that is associated
with thunderstorms.
3. A measure of how much moisture
is in the air.
4. The sun is directly overhead the
Tropic of _________ on the
summer solstice.
5. Used to measure wind speed.
6. The sun is directly overhead the
Tropic of Capricorn on the
_________ solstice.
8. The scale by which we rank tornadoes.
WHY THE WIND BLOWS GAMES METEREOLOGY CROSSWORD
9. This is an apparent force on thewind that is caused by the spin of
the Earth.
10. When all molecules stop moving,
you have reached the coldest possible
temperature called ________ zero.
12. The wind flows counter-clockwise
around an area of _______ pressure.
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