Precipitation

2. Have you ever just looked
at clouds?
▪ Why do we
have clouds?
▪ Why are there
different
shapes?
▪ What can they
tell us about
the weather?

3. Take Good Notes!
▪ There will be a
quiz on this
information

4. Understanding Clouds
▪ Clouds form as
warm air is
forced upward
▪ As the air is
forced upward,
it expands and
cools

5. Understanding Clouds
▪ As the air cools,
the relative
humidity
reaches 100%

6. Water vapor begins to condense in tiny drops
around nuclei. Nuclei are small particles of dust,
salt, and smoke in the atmosphere

7. Cloud Types
▪ There are
many
different
cloud types

8. Cloud Types
▪ Can you think of
the two main
ways that clouds
are classified?
▪ Shape, Height,
and sometimes
Rain Capacity

9. By Shape!
▪ There are three main cloud
types that are based on shape
▪ Stratus
▪ Cumulus
▪ Cirrus

10. Stratus Clouds
▪ Stratus
clouds form
a smooth,
even sheet
▪ They usually
form at low
altitudes

11. Stratus Clouds
▪ When air is
cooled and
condenses near
the ground, a
stratus cloud
know as _______
forms
▪ Know the
name?

13. Cumulus Clouds
▪ These are
masses of
puffy, white
clouds, often
with flat bases
▪ They form
when air
currents rise

14. Cumulus Clouds
▪ They can be
associated
with both fair
weather
and…….when
they get really
tall ___!

15. Thunderstorms!

16. Cirrus Clouds
▪ Cirrus clouds
are high, thin,
white,
feathery
clouds
containing ice
crystals

17. Cirrus Clouds
▪ Cirrus clouds
are usually
associated with
fair weather,
but they may
indicate
approaching
storms

18. By Height
▪ The prefix of cloud names can
describe the height of cloud
bases
▪ Cirro: High clouds above
6000m

19. By Height
▪ Alto: Middle elevation clouds
between 2000 to 6000m
▪ Strato: Low level clouds below
2000m

20. Rain Clouds
▪ Nimbus
clouds are
dark clouds
associated
with
precipitation

21. Rain Clouds
▪ When a nimbus
cloud is also a
towering
cumulus cloud,
it’s called a
cumulonimbus
cloud

22. Ready for a quick review?
▪ 1. Clouds can form when the
relative humidity reaches ____%
▪ 2. In order for clouds to form,
water vapor begins to condense
around ____of dust, salt, and
smoke

23. ▪ 3. Clouds are classified by ____
and____ and sometimes rain
capacity
▪ 4. Puffy, white clouds are called?
▪ 5. Mid elevation clouds between
2000 and 6000m
Ready for a quick
review?

24. Let’s see how you did!
1. 100
2. Nuclei
3. Shape and height
4. Cumulus
5. Alto

25. Precipitation
Precipitation
(pre-sip-uh-
tay-shun) is
any form of
water that falls
to the Earth's
surface.

26. Types of Precipitation
The type of precipitation that
falls to the ground depends
upon the formation process
and the temperatures of the
environment between the
cloud and the surface

27. Can you name the different
types of precipitation?
▪ Rain
▪ Snow
▪ Hail
▪ Sleet
▪ Freezing Rain

28. Rain
Rain develops
when growing
cloud droplets
become too
heavy to remain
in the cloud and
as a result, fall
toward the
surface as rain

29. ▪ Rain can also
begin as ice
crystals that
collect each
other to form
large
snowflakes
▪ As the falling
snow passes
through the
freezing level
into warmer
air, the flakes
melt

30. Rain from snow!

31. ▪ Snow is formed when ice
crystals form from water
vapor that is in the clouds
directly above your heads!
▪ This process is called
sublimation
Snow

33. Hail
Hail is formed
when updrafts
carry raindrops
upwards into
extremely cold
areas of the
atmosphere

34. Hail
The raindrops
merge and
freeze. When
the frozen
clumps get to
heavy they fall
to earth

35. Hail
Hail can vary
in size, from
the size of a
small stone to
that of a
baseball! So
be careful

36. Sleet
▪ Sleet is frozen
raindrops. Sleet
begins as rain or
snow and falls
through a deep
layer of cold air that
contains
temperatures below
freezing that exist
near the surface.

37. Sleet
Rain that falls
through this
extremely cold
layer has time
to freeze into
small pieces of
ice

38. Freezing Rain
▪ Freezing rain is falling rain that
cools below 0°C, but does not
turn to ice in the air
▪ The water is “supercooled”

39. When the drops hit anything
they instantly turn to ice!

41. 1. Nuclei for the formation of rain
drops can be small particles of: A)
salt, B) smoke, C) dust, D) all the
above
2. Which of these cloud types is not
based on the clouds shape: A)
stratus, B) nimbus, C) cumulus,
D) cirrus

42. 3. Mid elevation clouds between
2000 and 6000m: A) nimbus, B)
alto, C) cirro, D) strato
4. This form of precipitation is
supercooled: A) rain, B) snow,
C) sleet, D) freezing rain

43. 5. This form of precipitation
stays frozen all the way to the
ground: A) rain, B) snow, C)
sleet, D) freezing rain
Let’s see how you did!

44. The Answers!
1. D
2. B
3. B
4. D
5. B

46. Humidity and Relative Humidity
▪ Humidity is the amount of
water vapor in the air
▪ Relative humidity is a measure
of the amount of water vapor
that the air is holding,
compared to the amount it can
hold at a specific temperature

47. Humidity and Relative Humidity
▪ When the air is holding as
much moisture as it can, it’s
said to be saturated

48. Can you explain this graph?

49. ▪ In the cool of the morning, the
air can’t hold as much
moisture. We often have dew on
a summer morning
▪ Once the air has warmed, the
relative humidity drops since
the air can hold more moisture

50. You’ve seen water on the outside
of a cold drink?
▪ The cold air
around the
glass causes a
lower
temperature
at which the
air is
saturated

51. You’ve seen water on the outside
of a cold drink?
▪ The
temperature
at which air is
saturated and
condensation
takes place is
the dew point

52. THANK U