Transcript Weather Patterns

Weather Patterns
Table of Contents
Air Masses and Fronts
Storms
Predicting the Weather
Weather Patterns - Air Masses and Fronts
Comparing and Contrasting
As you read, compare and contrast the four types of fronts
by completing a table like the one below.
Front
How It Forms
Cold front
A cold air mass
overtakes a warm air
mass.
A warm air mass
overtakes a cold air
mass.
Cold and warm air
masses meet, but neither
can move the other.
A warm air mass is caught
between two cold air
masses.
Warm front
Stationary front
Occluded front
Types of
Weather
Clouds, possibly storms
with heavy precipitation
Clouds, light
precipitation
Clouds, precipitation
Clouds, precipitation
Weather Patterns - Air Masses and Fronts
Types of Air Masses
Air masses can be warm or cold, and humid or dry. As an air
mass moves into an area, the weather changes.
Weather Patterns - Air Masses and Fronts
Classifying Air Masses
Four major types of air
masses influence the
weather in North America:
maritime tropical, continental
tropical, maritime polar, and
continental polar.
Weather Patterns
Air Masses and Fronts
Introduction Pg. 596
1. What is an air mass?
An air mass is a huge body of air that has similar
temperature, humidity, and air pressure at any given height.
Types of Air Masses pg. 597-598
2. Scientists classify air masses according to ____ and ____.
temperature and humidity
3. Polar air masses typically have low air pressure.
False
4. Compare/Contrast Chart.
A. Maritime Tropical
B. Maritime Polar
C. Continental Tropical
D. Continental Polar
Weather Patterns
Air Masses and Fronts
4e. How are maritime tropical and maritime alike, how
are they different?
They are alike in that they are both humid. They
are different because the tropical air mass is warm and
the polar air mass is cool.
4.f. How are continental tropical and continental polar air
masses alike, and how are they different?
They are alike in that they are both dry. They are
different because the tropical air mass is warm and the
polar air mass is cool.
Weather Patterns
Air Masses and Fronts
How Air Masses Move pg. 599
5. In the continental United States, major wind belts generally
push air masses from ____ to ____.
west to east
6. How do jet streams affect air masses?
As the jet streams blow from west to east, air masses
are carried along their track.
Types of Fronts pg. 600-601
7. Drawings:
A. Cold Front
B. Warm Front
Weather Patterns - Air Masses and Fronts
How a Front Forms
The boundary where unlike air masses meet is called a front.
Weather Patterns - Air Masses and Fronts
Types of Fronts
Colliding air masses can form four types of fronts: cold fronts,
warm fronts, stationary fronts, and occluded fronts.
Weather Patterns
Air Masses and Fronts
Types of Fronts:
8. Cold front
C- A rapidly moving cold air mass runs into a slowly
moving warm air mass
9. Warm front
A- A moving warm air mass overtakes a slowly moving
cold air mass.
10. Stationary front
D- A cold air mass and a warm air mass meet and
remain stalled over an area.
11. Occluded front
B-A warm air mass is caught between two cooler air
masses.
Weather Patterns
Air Masses and Fronts
12. Sentences that are true about fronts:
• Cold fronts can bring violent thunderstorms.
• Warm fronts are associated with clouds and rain.
• Stationary fronts may bring many days of clouds and
precipitation.
Cyclones and Anticyclones pg.602-603
13. A swirling center of low air pressure is called a(an) ___.
cyclone
14. Winds spiral inward toward the center of a cyclone.
True
Weather Patterns
Air Masses and Fronts
15. What type of weather is associated with cyclones?
Storms and precipitation are associated with
cyclones.
16. Winds in an anticyclone spin clockwise in the
Northern Hemisphere.
True
17. What type of weather is generally associated with
anticyclones?
Dry, clear weather is generally associated with
anticyclones.
Weather Patterns - Air Masses and Fronts
Cyclones and Anticyclones
Winds spiral inward towards the low-pressure center of a
cyclone. Winds spiral outward from the high-pressure center
of an anticyclone.
Weather Patterns - Air Masses and Fronts
Weather Fronts Activity
Click the Active Art button to open a browser window and
access Active Art about weather fronts.
Weather Patterns
End of Section:
Air Masses and
Fronts
Weather Patterns - Storms
Sequencing
As you read, make a flowchart like the one below that shows
how a hurricane forms. Write each step of the process in a
separate box in the order in which it occurs.
Hurricane Formation
Begins as a low-pressure area over warm water,
or a tropical disturbance.
Warm, humid air rises and begins to spiral.
As air rises, more warm, moist air is drawn into the
system and the hurricane gains energy.
As winds spiral inward, bands of high winds
and heavy rains form.
Weather Patterns - Storms
Thunderstorm Formation
A thunderstorm forms when warm, humid air rises rapidly
within a cumulonimbus cloud.
Weather Patterns
Storms
Introduction pg.604
1. What is a storm?
A storm is a violent disturbance in the atmosphere.
Thunderstorm pg. 605-606
2. Types of clouds in which thunderstorms form:
Cumulonimbus
3. A sudden energy discharge between parts of a cloud,
between nearby clouds, or between a cloud and the
ground is called ____.
lightning
4. Sentences that are true about thunder.
• You hear it after you see the lightning that caused it.
•
It occurs because lightning heats the air.
Weather Patterns
Storms
5. A sudden, violent flood that occurs within a few hours, or
even minutes, of a storm is called a(n) ____.
flash flood
6. Sentences that is a way to stay safe in a thunderstorm:
• Avoid touching electrical appliances
• Get out of the water if you are swimming.
• Don’t use the telephone.
Tornadoes pg.606-608
7. What is a tornado?
A tornado is a rapidly whirling, funnel-shaped cloud
that reaches down from a storm cloud to touch Earth’s
surface.
Weather Patterns
Storms
8. Tornadoes develop in the same type of clouds that
bring thunderstorms.
True
9. Sentences that are true about where and when
tornadoes occur.
• Tornadoes occur often in the Great Plains.
• Tornadoes occur more often in the United States than
in any other country.
Weather Patterns
Storms
10. Flowchart:
1. Warm air is forced upward along a a._____ front.
a. cold
2. As the air rises, it b. _______.
b. cools
3. c.______ falls.
c. Heavy rain (sometimes with hail)
11. Where is the safest place to be during a tornado?
The safest place to be is in the basement of a
well-built building.
Weather Patterns - Storms
Tornado Formation
Tornadoes can form when warm, humid air rises rapidly in
thick cumulonimbus clouds—the same type of clouds that
bring thunderstorms.
Weather Patterns - Storms
Tornado Alley
Tornadoes in the U.S. are most likely to occur in a region
known as Tornado Alley.
Weather Patterns - Storms
Structure of a Hurricane
In a hurricane, air moves rapidly around a low-pressure area
called the eye.
Weather Patterns - Storms
Hurricane Andrew
The path of Hurricane Andrew over three consecutive days
can be seen below.
Weather Patterns
Storms
Hurricanes pg.610-611
12.Sentences that are true about a hurricane:
• It is a tropical storm.
• It forms over water.
13. The center of a hurricane is called the ____.
eye
14. Hurricanes do not last as long as other storms.
False
Weather Patterns
Storms
15. A “dome” of water that sweeps across the coast where the
hurricane lands is called a(n) ____.
storm surge
16. If you hear a hurricane warning and are told to evacuate,
you should leave the area immediately.
True
Winter Storms
17. When does snow fall?
Snow falls during a storm when the whole atmosphere
is colder than 0 degrees Celsius.
Weather Patterns
Storms
18. Sentences that are true about lake-effect snow:
• It occurs because land cools more rapidly than water.
• It occurs when humid air rises over a body of water and
later cools over land.
19. What should you do if you are caught in a
snowstorm?
You should try to find shelter from the wind,
cover exposed parts of your body, and stay dry. If you
are in a car, the driver should keep the engine running
only if the exhaust pipe is clear of snow.
Weather Patterns - Storms
Lake-Effect Snow
As cold dry air moves across the warmer water, it becomes
more humid as water vapor evaporates from the lake
surface. When the air reaches land and cools, snow falls.
Weather Patterns - Storms
More on Thunder and Lightning
Click the Planet Diary button for an activity about
thunder and lightning.
Weather Patterns - Storms
Tornadoes
Click the Video button to watch a movie about tornadoes.
Weather Patterns - Storms
Hurricanes
Click the Video button to watch a movie about hurricanes.
Weather Patterns
End of Section:
Storms
Weather Patterns - Predicting the Weather
Previewing Visuals
Before you read, preview Figure 21, a weather map. Then
write four questions that you have about the map in a graphic
organizer like the one below. As you read, answer your
questions.
Previewing Figure 21
Q. What type of front is located west of Okalahoma City?
A. A cold front
Q. What do the stick symbols indicate?
A. Amount of cloud cover, atmospheric pressure, wind direction
and speed, and temperature
Q. What are the slender, curvy lines?
A. Isobars, which join places with the same air pressure
Q. What does the symbol to the east of Florida mean?
A. A hurricane
Weather Patterns
Predicting the Weather
Weather Forecasting pg. 617
1. Scientists who study the causes of weather and try to
predicting it are called ____.
Meteorologist
2. Sources of weather information for meteorologists:
• Radar
• Instruments carried by balloons
• Satellites
Weather Technology pg. 618-619
3. In what two areas have improvements in technology
improved the accuracy of weather forecasts?
The areas are gathering weather data and using
computers to make forecasts.
Weather Patterns
Predicting the Weather
4. Weather forecasts for over three days into the future are
never reliable.
False
5. Flowchart:
A. weather station
B. Satellites
C. Computers
D. Meteorologists
E. Weather forecast
Weather Patterns
Predicting the Weather
5f. What happens to the calculations in step 3 if the data
collected is step 1 changes?
The calculations would change to reflect the revised
weather data.
5g. How would this change what is prepared in step 5?
The forecast prepared by meteorologists would
change to reflect the revised calculations produced by the
computer.
Weather Patterns
Predicting the Weather
6. Sentences that are true about weather balloons or weather
satellites:
• Weather balloons can carry instruments as high as the
stratosphere.
•Weather balloons often carry instruments that measure
temperature, air pressure, and humidity.
• Weather satellites take pictures of Earth from the exosphere.
7. Sentences that are true about computer weather forecasts:
• Computer forecasts are based on weather conditions from
many weather stations.
•When new weather data come in, new computer forecasts are
produced.
Weather Patterns - Predicting the Weather
Reading Weather Maps
This is the type of weather map produced by the National
Weather Service. It shows data collected from many weather
stations.
Weather Patterns - Predicting the Weather
Reading Weather Maps
Weather maps in newspapers use symbols to show fronts,
high- and low-pressure areas, and precipitation. Color bands
indicate different temperature ranges.
Weather Patterns - Predicting the Weather
Reading Weather Map Symbols
The figure below shows what various weather symbols
mean.
Weather Patterns
Predicting the Weather
Reading Weather Maps pg. 620-622
8. What data are indicated by symbols on a weather map?
The symbols indicate amount of cloud cover,
atmospheric pressure, wind direction, wind speed, and
temperature for individual weather stations. Weather maps
also show the location of air masses and fronts.
9. What are the temperature, air pressure, and wind direction
at the weather station represented by the symbol show?
The temperature is 55 degrees Farenheight, the air
pressure is 1028 millibars, and the wind is from the south-west
at 21-25 miles per hour.
Weather Patterns
Predicting the Weather
10. Isobars
B-Lines on a weather map joining places that have the
same air pressure.
11. Isotherms
A- Lines on a weather map joining places that have the
same temperature
12. What do the standard symbols on newspaper weather
maps show?
The symbols show fronts, areas of high and low
pressure, types of precipitation, and temperature range.
Weather Patterns
Predicting the Weather
13. The “butterfly effect” refers to the fact that a small change
in the weather today can mean a larger weather change in the
future.
True
Weather Patterns
Predicting the Weather
Key Terms:
1. Storm
2. Polar
3. Maritime
4. Isobars
5. Occluded
6. Tropical
7. Lightning
8. Isotherms
9. Tornado
10. Hurricane
11. meteorologist
Weather Patterns - Predicting the Weather
Red Sky
A red sky is one kind of observation that helps people to
predict the weather.
Weather Patterns - Predicting the Weather
Computer Weather Forecasting
Scientists use computers to
develop different models of how
a front may move. These
predictions are then used to
make weather forecasts. As
more data become available,
some models are found to be
incorrect, while others are found
to closely fit the predicted
conditions. The upper graph
shows the predicted air pressure
from two models. The lower
graph shows actual data for air
pressure.
Weather Patterns - Predicting the Weather
Computer Weather Forecasting
Reading Graphs:
What two variables are being
graphed?
Time of day and air pressure
Weather Patterns - Predicting the Weather
Computer Weather Forecasting
Interpreting Data:
How is air pressure predicted
to change according to each
model in the top graph?
According to model A, air
pressure will drop slightly
then increase. According to
model B, air pressure will
steadily decrease.
Weather Patterns - Predicting the Weather
Computer Weather Forecasting
Inferring:
Which computer model most
closely matches the actual air
pressure data?
Model B
Weather Patterns - Predicting the Weather
Computer Weather Forecasting
Predicting:
What weather would you
forecast for Monday and
Tuesday? Explain.
Stormy weather, clouds, and
precipitation accompany low
air pressure.
Weather Patterns - Predicting the Weather
More on Weather Maps
Click the Planet Diary button for an activity about
weather maps.
Weather Patterns
More on Doppler Radar
Click the PHSchool.com button for an activity
about Doppler radar.
Weather Patterns
End of Section:
Predicting the
Weather
Weather Patterns
Graphic Organizer
Type of Storm
Thunderstorms
Tornado
Hurricane
Where Forms
Within large
cumulonimbus clouds
Cumulonimbus cloud
Over warm ocean
water
Typical Time of
Year
Spring or Summer
Spring, early summer
Late summer and into
autumn
Safety Rules
Seek shelter, avoid
trees and water.
Move to a storm shelter
or basement if possible;
stay away from windows
and doors.
Evacuate or move inside
a well-built building.
Weather Patterns
End of Section:
Graphic Organizer