KS3 Geography lesson on rainfall.

1. Why does it rain?
Geography
Miss Sully

2. Air pressure
2
What is air pressure?
The force exerted onto
the Earth’s surface by
the weight of the air.
Air moves above the
Earth’s surface due to
different air pressure
which is caused by
different
temperatures.
Low High

3. Full face - me explaining using arm
movements (see script)
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4. VISUALISER - insert video whilst editing
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5. Air pressure
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Low High
Credit: Wiki Commons - Igor07 - O.rain.png and Wiki Commons - Ebrahim - Emojione2600.

6. Pause the video to complete your task
Task: Match the keywords with their definition.
1. Label your diagram
with a sun and rain
cloud.
2. Complete the following
sentence about the
creation of rain.
As ______ air rises it
c____, c________ and
forms c_____. Low High

7. Did you get?
1. Label your diagram with a sun and
rain cloud.
Check your diagram against mine.
1. Complete the following sentence
about the creation of rain.
As warm air rises it cools,
condenses and forms clouds.
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Low High
Credit: Wiki Commons - Igor07 - O.rain.png and Wiki Commons - Ebrahim - Emojione2600.

8. The 3 main causes of rainfall
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9. Relief rainfall
Warm moist air from the sea
rises up over mountains.
Warm air rises, cools,
condenses and forms clouds
which bring rain.
Air descends and warms on
the other side of the
mountain.
This creates a rain shadow.
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Warm Air Cold Air

10. Pause the video to complete your task
Task: Copy out the table and draw diagrams to show the
different stages of relief rainfall.
Prevailing
winds (main,
strong winds)
bring warm,
moist air to
the British
Isles.
Air is forced
to rise over
high areas of
land.
As it rises, air
cools and then
condenses.
Clouds form
and it rains.
Air descends
(goes down)
the other side
of the
mountain.
The falling
air warms,
and so
becomes
drier so no
rain.

11. Did you get?
11
Prevailing
winds (main,
strong winds)
bring warm,
moist air to
the British
Isles.
Air is forced
to rise over
high areas of
land.
As it rises, air
cools and then
condenses.
Clouds form
and it rains.
Air descends
(goes down)
the other side
of the
mountain.
The falling
air warms,
and so
becomes
drier so no
rain.

12. Frontal rainfall
When a cold polar air mass
meets a warm tropical air
mass the colder air mass is
heavier, so the lighter,
warmer air rises over the
top of it.
The warm rising air, cools,
condenses and forms
clouds.
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13. Option 1
When a cold polar air mass meets
a warm tropical air mass the
warmer air mass is heavier, so the
lighter, colder air rises over the top
of it.
Option 2
When a cold polar air mass meets
a warm tropical air mass the colder
air mass is heavier, so the lighter,
warmer air rises over the top of it.
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Which of the following statements is true about frontal
rainfall?
✔

14. Convectional rainfall
The land warms up the air
about it which causes it to
rise which then cools,
condenses, forms clouds
and rains.
This rainfall is common in
tropical areas and in areas
such as south east England
during warm sunny spells.
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15. Pause the video to complete your task
Task: Label the
diagram using the
options below.
Rain can then occur
Sea
Land
Sun heats the land and
the air above
Warm air rises, cools and
condenses, forming
clouds
A
D
B
C E

16. 16
Did you get?
E - Rain can then occur
A - Sea
D - Land
B - Sun heats the land
and the air above
A
D
B
C E
C - Warm air rises, cools
and condenses, forming
clouds

17. Pause the video to complete your task
Task: Read the description of a place and decide which type
of rainfall (frontal, convectional or relief) is most likely to be
happening.
Rainfall:
The Himalayas. A huge mountain
range in Asia stretching from China,
India, Bhutan, Pakistan and Nepal.
The UK Midlands where polar air
masses can sometimes meet
tropical air masses.
The south coast of England on a
hot summer's day.
Northern Australia which has a
tropical climate - very hot and wet.
Rainfall:
Rainfall:
Rainfall:

18. Pause the video to complete your task
Task: Read the description of a place and decide which type
of rainfall (frontal, convectional or relief) is most likely to be
happening.
Rainfall: Relief
The Himalayas. A huge mountain
range in Asia stretching from China,
India, Bhutan, Pakistan and Nepal.
The UK Midlands where polar air
masses can sometimes meet
tropical air masses.
The south coast of England on a
hot summer's day.
Northern Australia which has a
tropical climate - very hot and wet.
Rainfall:
Rainfall:
Rainfall:

19. Rainfall: Relief
The Himalayas. A huge mountain
range in Asia stretching from China,
India, Bhutan, Pakistan and Nepal.
Rainfall: Frontal
The UK Midlands where polar air
masses can sometimes meet
tropical air masses.
Option 3 Option 4
Rainfall: Convectional
The south coast of England on a
hot summer's day.
Rainfall: Convectional
Northern Australia which has a
tropical climate - very hot and wet.
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Did you get?

20. Pause the video to complete your task
Main task:
The 2 main causes of rainfall in the UK are relief and frontal.
Explain why they are the causes in the UK.
Success Criteria
What causes the air
to rise?
What happens once
it does rise?
Relief rainfall in the UK is caused by warm,
moist air from the sea rising over
mountains.(✔)
As the warm air rises, it cools and condenses,
forming clouds which leads to rainfall. (✔)
Air descends and warms on the other side of
the mountain and leaves a rain shadow. (✔)

21. Pause the video to complete your task
Main task:
The 2 main causes of rainfall in the UK are relief and frontal.
Explain why they are the causes in the UK.
Success Criteria
Frontal rainfall
What causes the air to rise?
What happens once it does rise?

22. Did you get?
When cold polar air
masses meet a warm
tropical air mass (✔) the
colder air mass is heavier,
so the lighter, warmer air
rises over the top of it.(✔)
This then leads to rainfall
as the warm air cools, and
condenses which forms
clouds.(✔)
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23. Why does it rain?
Geography
Miss Sully