Ch 7 - Aviation Weather - Questions 631 - 701

Question 1

Every physical process of weather is accompanied by, or is the result of, a

Answer 1

Heat exchange

Question 2

What causes variations in altimeter settings between weather reporting points?

Answer 2

Unequal heating if the Earth’s surface

Question 3

The wind at 5,000 feet AGL is southwesterly while the surface wind is southerly. This difference in direction is primarily due to

Answer 3

Friction between the wind and the surface

Question 4

The development of thermals depends upon

Answer 4

Solar heating

Question 5

Convective cirucaltion patterns associated with sea breezes are caused by

Answer 5

Cool, dense air moving inland from over the water

Question 6

The boundary between two different air masses is referred to as a

Answer 6

Front

Question 7

One weather phenomenon which will always occur when flying across a front is a change in the

Answer 7

Wind direction

Question 8

One of the most easily recognized discontinuities across a front is

Answer 8

A change in temperature

Question 9

If there is thunderstorm activity in the vicinity of an airport at which you plan to land, which hazardous atmospheric phenomenon might be expected on the landing approach?

Answer 9

Wind-shear turbulence

Question 10

A nonfrontal, narrow band of active thunderstorms that often develop ahead of cold front is known as a

Answer 10

Squall line

Question 11

What conditions are necessary for the formation of thunderstorms?

Answer 11

High humidity, lifting force, and unstable conditions

Question 12

During the life cycle of a thunderstorm, which stage is characterized predominately by downdrafts?

Answer 12

Dissipating

Question 13

Thunderstorms reach their greatest intensity during the

Answer 13

Mature stage

Question 14

What feature is normally associated with the cumulus stage of a thunderstorm?

Answer 14

Continuous updraft

Question 15

Which weather phenomenon signals the beginning of the mature stage of a thunderstorm?

Answer 15

Precipitation beginning to fall

Question 16

Thunderstorms which generally produce the most intense hazard to aircraft are

Answer 16

Squall line thunderstorms

Question 17

Which weather phenomenon is always associated with a thunderstorm?

Answer 17

Lightning

Question 18

The mature stage of a thunderstorm begins with

Answer 18

The start of precipitation

Question 19

The destination airport has one runway, 8-26, and the wind is calm. The normal approach in calm wind is a left-hand pattern to runway 8. There is no other traffic at the airport. A thunderstorm about 6 miles west is beginning its mature stage, and rain is starting to reach the ground. The pilot decides to

Answer 19

Delay departure until the thunderstorm has dissipated

Question 20

You are avoiding a thunderstorm that is in your flightpath. You are over 20 miles from the cell; however, you are under the anvil of the cell. Is this a hazard?

Answer 20

Yes, hail can be discharged from the anvil

Question 21

One in-flight condition necessary for structural icing to form is

Answer 21

Visible moisture

Question 22

In which environment is aircraft structural ice most likely to have the highest accumulation rate?

Answer 22

Freezing rain

Question 23

The presence of ice pellets at the surface is evidence that there

Answer 23

Is a temperature inversion with freezing rain at a higher altitude

Question 24

How will frost on the wings of an airplane affect takeoff performance?

Answer 24

Frost will disrupt the smooth flow of air over the wing, adversely affecting its lifting capability.

Question 25

Why is frost considered hazardous to flight?

Answer 25

Frost spoils the smooth flow of air over the wings, thereby decreasing litigant capability

Question 26

How does frost affect the lifting surfaces of an airplane on takeoff?

Answer 26

Frost may prevent the airplane from becoming airborne at normal takeoff speed

Question 27

Which conditions result in the formation of frost?

Answer 27

The temperature of the collecting surface is at or below the dew point of the adjacent air and the dew point is below freezing

Question 28

An almond or lens-shaped cloud which appears stationary, but which may contain winds of 50 knots or more, is referred to as

Answer 28

A lenticular cloud

Question 29

Crests of standing mountain eaves may be marked by stationary, lens-shaped clouds known as

Answer 29

Standing lenticular clouds

Question 30

Possible mountain eaves turbulence could be anticipated when winds of 40 knots or greater blow

Answer 30

Across a mountain ridge, and the air is table.

Question 31

Where does wind shear occur?

Answer 31

At all altitudes, in all directions

Question 32

A pilot can expect a wind-shear zone in a temperature inversion whenever the wind speed at 2,000 to 4,000 feet above the surface is at least

Answer 32

25 Knots

Question 33

When may hazardous wind shear be expected?

Answer 33

In areas of low-level temperature inversion, frontal zones and clean air turbulence

Question 34

If the temperature/dewpoint spread is small and decreasing, and the temperature is 62 degrees F, what type weather is most likely to develop?

Answer 34

Fog or low clouds

Question 35

What is meant by the term "dewpoint"?

Answer 35

The temperature at which condensation and evaporation are equal

Question 36

The amount of water vapour which air can hold depends on the

Answer 36

Air temperature

Question 37

What are the processes by which moisture is added to unsaturated air?

Answer 37

Evaporation and sublimation

Question 38

Clouds, fog or dew will always form when

Answer 38

Water vapour condenses

Question 39

Low-level turbulence can occur and icing can become hazardous in which type of fog?

Answer 39

Steam fog

Question 40

In which situation is advection fog most likely to form?

Answer 40

An air mass moving in land from the coast in winter

Question 41

What situation is most conductive to the formation of radiation fog?

Answer 41

Warm, moist air over low, flatland areas on clear, calm nights

Question 42

What types of fog depend upon wind in order to exist?

Answer 42

Advection fog and upslope fog

Question 43

Clouds are divided into four families according to their

Answer 43

Height range

Question 44

The suffix "nimbus", used naming clouds, means

Answer 44

A rain cloud

Question 45

The conditions necessary for the formation of cumulonimbus clouds are a lifting action and

Answer 45

Unstable, moist air

Question 46

What clouds have the greatest turbulence?

Answer 46

Cumulonimbus

Question 47

What could types indicate convective turbulence?

Answer 47

Towering cumulus clouds

Question 48

At approximately what altitude above the surface would the pilot expect the base of cumuliform clouds if the surface air temperature is 82 degrees F an the dewpoint is 38 degrees F?

Answer 48

10,000 feet AGL

Question 49

What is the approximate base of the cumulus clouds if the surface air temperature at 1,000 feet MSL is 70 degrees F and the dewpoint is 48 degrees F?

Answer 49

6,000 feet MSL

Question 50

Cumulus clouds often indicate

Answer 50

Possible turbulence

Question 51

What is a characteristic of stable air?

Answer 51

Stratiform clouds

Question 52

When warm, moist, stable air flows upslope, it

Answer 52

Produces stratus type clouds

Question 53

If an unstable air mass if forced upward, what type of clouds can be expected?

Answer 53

Clouds with considerable vertical development and associated turbulence

Question 54

What are the characteristics of unstable air?

Answer 54

Turbulence and good surface visibility

Question 55

A stable air mass is most likely to have which characteristic?

Answer 55

Poor surface visibility

Question 56

Steady precipitation preceding a front is an indication of

Answer 56

Stratiform clouds with little or no turbulence

Question 57

What are the characteristics of a moist, unstable air mass?

Answer 57

Cumuliform clouds and showery precipitation

Question 58

What measurement can be used to determine the stability of the atmosphere?

Answer 58

Actual lapse rate

Question 59

What would decrease the stability of an air mass?

Answer 59

Warming from below

Question 60

What are the characteristics of an unstable atmosphere?

Answer 60

A warm, humid air mass

Question 61

Clouds with extensive vertical development over mountainous terrain are a sign of

Answer 61

An unstable air mass