Transcript Air Masses and Fronts 2x

AIR MASSES
AND
FRONTS
Key Vocabulary:
-Fronts
-Clouds
EQ: How do air masses
create weather?
Objective: Explain how
interactions of air masses form
fronts, clouds, and affect wind
patterns.
Final Exam
By the end of today’s lesson you will be able to correctly
answer the following question:
Which most likely occurs when a fast-moving cold air
mass moves into a region of warmer, moist air?
A. It causes light precipitation for a long period of time.
B. It causes light precipitation for a short period of time.
C. It causes heavy precipitation for a long period of time.
D. It causes heavy precipitation for a short period of time
Final Exam
By the end of today’s lesson you will be able to correctly
answer the following question:
A world map with lines of latitude and longitude is shown.
At which location would a tropical air mass most likely
form?
A. 20° N, 120° W
B. 40° N, 70° W
C. 60° S, 30° E
D. 80° S, 10° E
1. How would you describe the temperature of the
oceans in areas near the equator?
2. How would you describe the temperature of the
oceans in areas near the poles?
3. Which heats more rapidly, land or water?
4. Make a prediction: would you expect the air to be
more humid in Charlotte, or in Myrtle Beach? Why?
Jot down all the words or
phrases you can think of that
you might hear in a
Weather report
or forecast
http://www.wcnc.com/video?id=188583721&sec=552547&ref=rcvidmod
After list, watch “futurecast”
What is an
air mass?
Air mass: a large volume
of air in which temperature
and moisture are nearly
the same in different
locations at the same
altitude
How are air
masses
classified?
Air masses are classified by
their overall temperature
and the surface over
which they form
As air masses move, their
characteristics change and
so does the weather in the
area over which they are
moving
Temperature:
How are air
masses
classified?
Tropical = warm (equator)
Polar = cold (poles)
Surface origin:
Maritime = ocean (moist/humid)
Continental = land (dry)
cP = continental polar (cold, dry,
stable)
cT = continental tropical (warm,
dry, unstable surface air)
mP = maritime polar (cool, humid,
unstable)
mT = maritime tropical (warm,
moist, unstable)
How do air
masses
impact
weather?
•
•
Weather patterns are a
result of the movement
of air masses
An air mass may take
several days to move
over an area – this
causes the area to
experience fairly
constant weather
How do air
masses
impact
weather?
•
Much of the weather in
North America is influenced
by continental polar and
maritime tropical air masses
•
When an air mass moves, it
carries the temperature and
moisture conditions with it
How do air
masses
create
fronts?
When two air masses
meet, they from a front
•Front: boundary that
separates two air
masses
•Fronts are often
associated with some
form of precipitation
How are air
density and
fronts
related?
Recall: what is more
dense, cold or warm
water?
Then, what would you
expect to be more
dense, cold or warm
air?
How are air
density and
fronts
related?
The front surface slopes
at a low angle so that
warmer, less dense air
rises over cooler, denser
air
•
In most cases, the
distribution of pressure
across a front causes one
air mass to move faster
than the other, mixing air
of different densities
https://www.youtube.com/watch?v=9U0W3-pruuY
Weather Channel – what is a front?
How are
fronts and
weather
related?
When a fast-moving cold
(polar) air mass moves into a
region of warmer moist
(maritime tropical) air - brief,
heavy storms occur
•After it passes, air is cooler
When a fast-moving warm air
mass moves into a region of
cooler air - steady but light
rain/snow occurs
•After it passes, air is warmer
How are
fronts and
clouds
related?
Clouds are created
when a front pushes air
up in the atmosphere,
allowing air to expand
& cool, and water to
condense – forming a
cloud
•This is called adiabatic
cooling – when air is allowed
to expand, it cools
Fronts foldable
Description of front
Diagram of front formation
HIGHLIGHT weather experienced
Description of front
Diagram of front formation
HIGHLIGHT weather experienced
Description of front
Diagram of front formation
HIGHLIGHT weather experienced
Description of front
HIGHLIGHT weather experienced
Diagram of front formation
Final Exam
By the end of today’s lesson you will be able to correctly
answer the following question:
A world map with lines of latitude and longitude is shown.
At which location would a tropical air mass most likely
form?
A. 20° N, 120° W
B. 40° N, 70° W
C. 60° S, 30° E
D. 80° S, 10° E
Final Exam
By the end of today’s lesson you will be able to correctly
answer the following question:
A world map with lines of latitude and longitude is shown.
At which location would a tropical air mass most likely
form?
A.20° N, 120° W
B. 40° N, 70° W
C. 60° S, 30° E
D.80° S, 10° E
Final Exam
By the end of today’s lesson you will be able to correctly
answer the following question:
Which most likely occurs when a fast-moving cold air
mass moves into a region of warmer, moist air?
A. It causes light precipitation for a long period of time.
B. It causes light precipitation for a short period of time.
C. It causes heavy precipitation for a long period of time.
D. It causes heavy precipitation for a short period of time
Final Exam
By the end of today’s lesson you will be able to correctly
answer the following question:
Which most likely occurs when a fast-moving cold air
mass moves into a region of warmer, moist air?
A. It causes light precipitation for a long period of time.
B. It causes light precipitation for a short period of time.
C. It causes heavy precipitation for a long period of time.
D. It causes heavy precipitation for a short period of
time