Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BFS - Meteorology > C13 - Cloud Formation and Precipitation > Flashcards

C13 - Cloud Formation and Precipitation Flashcards

1
Q

Define Advection?

A

Horizontal Movement of Air.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Describe an example of Advection?

A

Warm, moist air moves over a cooler surface is cooled from below.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

During Advection what happens in the cloud when along the surface (2)?

A
  • Cause Condensation.

- Low-Level Clouds.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

During Advection, when the Visibility is less than 1,000m, what weather phenomenon occurs?

A

Advection Fog.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What two factors are required to lift Advection Fog to become Stratus Clouds?

A
  • Wind.

- Rising Temperatures.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

True or False. Continued cooling from Advection Fog can lead to a layer of Nimbostratus Clouds?

A

True.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Define Radiation?

A

Layer of Air in contact with the surface cools by Conduction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

During Radiation, if the Air cooled below its Dew Point, what weather phenomenon occurs?

A

Radiation Fog.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Radiation is a winter ‘____’ system?

A

High Pressure.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What conditions are needed to produce Radiation Fog (3)?

A
  • Clear Skies.
  • Winter Night.
  • < 5kt of Wind.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What two factors are required to lift Radiation Fog to become Stratus Clouds?

A
  • Wind.

- Rising Temperatures.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

True or False. Uplift is the most significant cause of Cloud Formation? Why (2)?

A
  • True.

- Air is forced to rise, expands and cools adiabatically.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Unsaturated Air cools at the rate of?

A

3°C per 1,000 ft.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

The Dew Point of Air decreases at the rate of?

A

0.5°C per 1,000 ft.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Further reduction in Temperature caused by continuing Uplift, results in water condensing out into visible moisture droplets. This occurs at the ‘____’?

A

Condensation Level.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the formula to calculate Cloud Base?

A

(Temperature – Dew Point) x 400.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

The lower the Dew Point, relative to the Temperature of the Air Parcel, the ‘____’ the Cloud Base?

A

Higher.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How can we calculate the Cloud Tops?

A

When Environmental Lapse Rate is equal to Saturated Adiabatic Lapse Rate.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Increased warming in Stable Atmospheric Conditions will cause Clouds to ‘____’?

A

Dissipate.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

True or False. Cloud will not dissipate with general changes in the characteristics of an Air Mass?

A

False.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the most common factors which causes Air to Rise (5)?

A
  • Turbulent Uplift/Mixing.
  • Orographic Uplift.
  • Convection.
  • Frontal Uplift.
  • Convergence.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Turbulence near the surface is caused by the disruption of smooth airflow by ‘____’ and ‘____’ effects. Either of these effects can produce a ‘____’ of air from the surface to a height of about ‘____’ (4)?

A
  • Mechanical.
  • Thermal.
  • Turbulent Layer/Friction Layer.
  • 2,000 ft.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

When Wind meets a physical barrier such as hills or mountains the Air is forced to ‘____’ and thus begins to ‘____’. This is known as ‘____’ (3)?

A
  • Rise.
  • Cool Adiabatically.
  • Orographic Uplift.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

True or False. Hills and Mountains are prolific Cloud producers?

A

True.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Orographic Cloud in Unstable Conditions are cause what type of Clouds?

A

Rapid growth of Cumuliform Clouds.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

True or False. Severe Storms can’t be generated by Mountains which can cause Severe Turbulence, Icing, Lighting and Hail?

A

False. It can.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Orographic Cloud in Stable Conditions are cause what type of Clouds?

A

Cap Clouds (Stratus).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Air is forced to ‘____’ on the Windward side of the Mountain and to ‘____’ on the Leeside of the Mountain?

A
  • Rise.

- Sink.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

On the Leeward side of a Mountain the Cloud eventually evaporates due to ‘____’?

A

Adiabatic Warming.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

When the Wind is strong, Orographic effects in a Stable Atmosphere can produce what weather phenomenon (3)?

A
  • Mountain Waves.
  • Lenticularis.
  • Rotor Clouds.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

When Air at Low-Levels are warmed by the surface, it heats up and expands. The reduction in Density causes it to become buoyant and to rise. This is known as?

A

Convection Uplift.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Convection currents are strongest over land masses during which period?

A

Summer Afternoons.

33
Q

What type of Cloud can form under Convection Uplift?

A

Cumuliform Clouds.

34
Q

Define a Front?

A

Boundary between a large mass of Warm Air and a large mass of Cold Air.

35
Q

When a cold mass of Air moves, the cold, denser Air slides underneath the warmer lighter Air. This is known as?

A

A Cold Front.

36
Q

When a warm mass of Air moves, the warm Air rides up over the cold denser Air. This is known as?

A

A Warm Front.

37
Q

Frontal Uplift is the most common form of Uplift found in the ‘____’ of the World?

A

Mid-Latitudes.

38
Q

When Wind from one direction meets Wind coming from the opposite direction, this causes a general uplifting at the meeting point. This is known as?

A

Convergence Uplift.

39
Q

Convergence Uplift is a common feature of ‘____’ and is often associated with ‘____’ conditions (2)?

A
  • Low Pressure Troughs.

- Poor.

40
Q

What is the name of the most famous Convergence in the World?

A

Intertropical Convergence Zone (ITCZ).

41
Q

What type of Cloud are found in the ITCZ?

A

Cumuliform Clouds.

42
Q

What Hazards associated with Precipitation (6)?

A
  • Reduced Visibility.
  • Airframe Icing.
  • Malfunction of Aircraft Sensors.
  • Flame-out of Gas Turbine Engines.
  • Structural Damage.
  • Degrade Take-off and Landings performance.
43
Q

The type of Precipitation depends on what two factors?

A
  • Cloud Structure.

- Speed of Ascending Air.

44
Q

When ascending air cools below its ‘____’, ‘____’ or ‘____’ takes place and Water Vapour changes state either to Liquid Water or Ice Crystals (3)?

A
  • Dew Point.
  • Condensation.
  • Sublimation.
45
Q

Intense ‘____’ produces the heaviest Water Droplets and the largest Hailstones?

A

Cumulonimbus.

46
Q

The process of Ice Crystal growth occurs in Clouds which are below ‘____’ and which contain a mixture of Supercooled Water and Ice?

A

0°C.

47
Q

True or False. Water Droplets are easier to form that Ice Crystals?

A

False. Ice Crystals are easier.

48
Q

As Ice Crystals grow and fall, they pass through the Cloud Base, if this is above ‘____’ the Ice Crystals will ‘____’ and fall as ‘____’ (3)?

A
  • Freezing.
  • Melt.
  • Rain.
49
Q

If there is a sub-zero layer of Air below the Cloud, the rain may ‘____’ in the form of ‘____’ (2)?

A
  • Refreeze.

- Ice Pellets.

50
Q

If the layer of Freezing Air is at the surface the Precipitation will fall as ‘____’?

A

Freezing Rain.

51
Q

How can a Pilot avoid Freezing Rain?

A

By climbing above the Cloud.

52
Q

Define Coalescence Theory?

A

Formation of Precipitation in Clouds warmer that 0°C.

53
Q

During Condensation/Sublimation, what is the size of Water Droplets/Ice Crystals?

A

0.02mm.

54
Q

What size of Water Droplets can be found in Updraughts of Air (2)?

A
  • Strong Updraught = Large Droplets.

- Weak Updraught = Small Droplets.

55
Q

What is the Abbreviation, Water Droplet size and Cloud type association for Drizzle (3)?

A
  • DZ.
  • 0.5mm.
  • Stratiform Clouds.
56
Q

What is the Abbreviation, Water Droplet size and Cloud type association for Rain (3)?

A
  • RA.
  • 0.5 to 5.5mm.
  • Cumuliform Clouds.
57
Q

What happens to Water Droplets bigger than 5.5mm?

A

They break apart during descent.

58
Q

Unbranched ‘____’ fall as needles, columns or plates of Ice. What am I?

A

Ice Crystals.

59
Q

Ice Crystals which are branched, star-shaped or mixed with unbranched crystals. What am I and my abbreviation code (2)?

A
  • Snow.

- SN.

60
Q

Larger Snowflakes are produced ‘____’ -5°C and smaller Snowflakes are produced ‘____’ -5°C (2)?

A
  • Above.

- Below.

61
Q

Precipitation can fall as Snow as long as the Surface Temperature does not exceed ‘____’?

A

+4°C.

62
Q

Very small, white, opaque grains of Ice with a diameter less than 1mm. What am I?

A

Snow Grains.

63
Q

White and often called soft hail with a diameter between 2 to 5mm. What am I?

A

Snow Pellets.

64
Q

Larger than Snow Pellets and comprise clear Ice. What am I and my abbreviation code (2)?

A
  • Ice Pellets.

- PL.

65
Q

Rain and Snow falling together, or Snow Melting as it falls. What am I?

A

Sleet.

66
Q

White or opaque and vary greatly in Size. What am I and my abbreviation code (2)?

A
  • Hail.

- GR/GS.

67
Q

Hail of less than ‘____’ is called Small Hail and the abbreviation code is ‘____’. Hail which is larger the abbreviation code is ‘____’ (3)?

A
  • 5mm.
  • GS.
  • GR.
68
Q

Hailstones can only form deep in which type of Clouds?

A

Cumulonimbus Clouds.

69
Q

What is the Intensity of Precipitation for Rain and Snow (3)?

A
  • Slight = < 0.5.
  • Moderate = 0.5 to 4.
  • Heavy = > 4.
70
Q

What is the Intensity of Precipitation for Rain/Hail Showers (4)?

A
  • Slight = < 2.
  • Moderate = 2 to 10.
  • Heavy = 10 to 50.
  • Violent = > 50.
71
Q

Name three types of Continuity of Precipitation?

A
  • Continuous.
  • Intermittent.
  • Showers.
72
Q

Define Continuous Precipitation?

A

No breaks for more than 60 minutes.

73
Q

Define Intermittent Precipitation?

A

No breaks for less than 60 minutes.

74
Q

Define Showers?

A

Associated with Rain, Snow, Sleet or Hail.

75
Q

Name two types of Clouds where Drizzle can be found?

A
  • Stratus (St).

- Stratocumulus (Sc).

76
Q

Name two types of Clouds where Continuous Rain and Snow can be found?

A
  • Thick Altostratus (As).

- Nimbostratus (Ns).

77
Q

Which type of Cloud can Hail be found?

A

Cumulonimbus (Cb).

78
Q

Name two types of Clouds where Intermittent Rain and Snow can be found?

A
  • Thick Altostratus (As).

- Stratocumulus (Sc).

79
Q

Name two types of Clouds where Rain and Snow Showers can be found?

A
  • Heavy Cumulus (Cu).

- Heavy Cumulonimbus (Cb).

BFS - Meteorology (22 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions