What is density altitude?

A. The height above the standard datum plane.

B. The pressure altitude corrected for nonstandard temperature.

C. The altitude read directly from the altimeter.

(Refer to figure 8 .) What is the effect of a temperature decrease and a pressure altitude increase on the density altitude from 90 °F and 1,250 feet pressure altitude to 55 °F and 1,750 feet pressure altitude?

A. 1,300-foot decrease.

B. 1,700-foot decrease.

C. 1,700-foot increase.

(Refer to figure 8 .) Determine the pressure altitude at an airport that is 1,386 feet MSL with an altimeter setting of 29.97.

A. 1,341 feet MSL.

B. 1,451 feet MSL.

C. 1,562 feet MSL.

(Refer to figure 8 .) Determine the pressure altitude with an indicated altitude of 1,380 feet MSL with an altimeter setting of 28.22 at standard temperature.

A. 2,913 feet MSL.

B. 2,991 feet MSL.

C. 3,010 feet MSL.

(Refer to figure 8 .) Determine the pressure altitude at an airport that is 3,563 feet MSL with an altimeter setting of 29.96.

A. 3,527 feet MSL.

B. 3,556 feet MSL.

C. 3,639 feet MSL.

(Refer to figure 8 .) What is the effect of a temperature increase from 30 to 50 °F on the density altitude if the pressure altitude remains at 3,000 feet MSL?

A. 900-foot increase.

B. 1,100-foot decrease.

C. 1,300-foot increase.

What are the standard temperature and pressure values for sea level?

A. 15 °C and 29.92 inches Hg.

B. 59 °C and 1013.2 millibars.

C. 59 °F and 29.92 millibars.

Where does wind shear occur?

A. Only at higher altitudes.

B. Only at lower altitudes.

C. At all altitudes, in all directions.

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

A. Showery precipitation.

B. Turbulent air.

C. Poor surface visibility.

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

A. movement of air.

B. pressure differential.

C. heat exchange.

What causes variations in altimeter settings between weather reporting points?

A. Unequal heating of the Earth's surface.

B. Variation of terrain elevation.

C. Coriolis force.

A temperature inversion would most likely result in which weather condition?

A. Clouds with extensive vertical development above an inversion aloft.

B. Good visibility in the lower levels of the atmosphere and poor visibility above an inversion aloft.

C. An increase in temperature as altitude is increased.

The most frequent type of ground or surface-based temperature inversion is that which is produced by

A. terrestrial radiation on a clear, relatively still night.

B. warm air being lifted rapidly aloft in the vicinity of mountainous terrain.

C. the movement of colder air under warm air, or the movement of warm air over cold air.

Which weather conditions should be expected beneath a low-level temperature inversion layer when the relative humidity is high?

A. Smooth air, poor visibility, fog, haze, or low clouds.

B. Light wind shear, poor visibility, haze, and light rain.

C. Turbulent air, poor visibility, fog, low stratus type clouds, and showery precipitation.

Which factor would tend to increase the density altitude at a given airport?

A. An increase in barometric pressure.

B. An increase in ambient temperature.

C. A decrease in relative humidity.

Under what condition is pressure altitude and density altitude the same value?

A. At sea level, when the temperature is 0 °F.

B. When the altimeter has no installation error.

C. At standard temperature.

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

A. stronger pressure gradient at higher altitudes.

B. friction between the wind and the surface.

C. stronger Coriolis force at the surface.

What is meant by the term 'dewpoint'?

A. The temperature at which condensation and evaporation are equal.

B. The temperature at which dew will always form.

C. The temperature to which air must be cooled to become saturated.

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

A. dewpoint.

B. air temperature.

C. stability of the air.

Clouds, fog, or dew will always form when

A. water vapor condenses.

B. water vapor is present.

C. relative humidity reaches 100 percent.

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

A. Evaporation and sublimation.

B. Heating and condensation.

C. Supersaturation and evaporation.

Which conditions result in the formation of frost?

A. The temperature of the collecting surface is at or below freezing when small droplets of moisture fall on the surface.

B. The temperature of the collecting surface is at or below the dewpoint of the adjacent air and the dewpoint is below freezing.

C. The temperature of the surrounding air is at or below freezing when small drops of moisture fall on the collecting surface.

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

A. are thunderstorms in the area.

B. has been cold frontal passage.

C. is a temperature inversion with freezing rain at a higher altitude.

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

A. 4,000 feet MSL.

B. 5,000 feet MSL.

C. 6,000 feet MSL.

What are characteristics of a moist, unstable air mass?

A. Cumuliform clouds and showery precipitation.

B. Poor visibility and smooth air.

C. Stratiform clouds and showery precipitation.

What are characteristics of unstable air?

A. Turbulence and good surface visibility.

B. Turbulence and poor surface visibility.

C. Nimbostratus clouds and good surface visibility.

Moist, stable air flowing upslope can be expected to

A. produce stratus type clouds.

B. cause showers and thunderstorms.

C. develop convective turbulence.

What feature is associated with a temperature inversion?

A. A stable layer of air.

B. An unstable layer of air.

C. Chinook winds on mountain slopes.

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

A. Stratus clouds with little vertical development.

B. Stratus clouds with considerable associated turbulence.

C. Clouds with considerable vertical development and associated turbulence.

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

A. Atmospheric pressure.

B. Actual lapse rate.

C. Surface temperature.

What would decrease the stability of an air mass?

A. Warming from below.

B. Cooling from below.

C. Decrease in water vapor.

What is a characteristic of stable air?

A. Stratiform clouds.

B. Unlimited visibility.

C. Cumulus clouds.

The suffix 'nimbus,' used in naming clouds, means

A. a cloud with extensive vertical development.

B. a rain cloud.

C. a middle cloud containing ice pellets.

Clouds are divided into four families according to their

A. outward shape.

B. height range.

C. composition.

What cloud types would indicate convective turbulence?

A. Cirrus clouds.

B. Nimbostratus clouds.

C. Towering cumulus clouds.

What clouds have the greatest turbulence?

A. Towering cumulus.

B. Cumulonimbus.

C. Nimbostratus.

One of the most easily recognized discontinuities across a front is

A. a change in temperature.

B. an increase in cloud coverage.

C. an increase in relative humidity.

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

A. wind direction.

B. type of precipitation.

C. stability of the air mass.

Steady precipitation preceding a front is an indication of

A. stratiform clouds with moderate turbulence.

B. cumuliform clouds with little or no turbulence.

C. stratiform clouds with little or no turbulence.

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

A. frontolysis.

B. frontogenesis.

C. front.

When may hazardous wind shear be expected?

A. When stable air crosses a mountain barrier where it tends to flow in layers forming lenticular clouds.

B. In areas of low-level temperature inversion, frontal zones, and clear air turbulence.

C. Following frontal passage when stratocumulus clouds form indicating mechanical mixing.

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

A. 10 knots.

B. 15 knots.

C. 25 knots.

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

A. small temperature/dewpoint spread.

B. stratiform clouds.

C. visible moisture.

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

A. Cumulus clouds with below freezing temperatures.

B. Freezing drizzle.

C. Freezing rain.

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

A. The appearance of an anvil top.

B. Precipitation beginning to fall.

C. Maximum growth rate of the clouds.

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

A. unstable air containing an excess of condensation nuclei.

B. unstable, moist air.

C. either stable or unstable air.

What conditions are necessary for the formation of thunderstorms?

A. High humidity, lifting force, and unstable conditions.

B. High humidity, high temperature, and cumulus clouds.

C. Lifting force, moist air, and extensive cloud cover.

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

A. Cumulus.

B. Dissipating.

C. Mature.

Thunderstorms reach their greatest intensity during the

A. mature stage.

B. downdraft stage.

C. cumulus stage.

Thunderstorms which generally produce the most intense hazard to aircraft are

A. squall line thunderstorms.

B. steady-state thunderstorms.

C. warm front thunderstorms.

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

A. prefrontal system.

B. squall line.

C. dry line.

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?

A. Precipitation static.

B. Wind-shear turbulence.

C. Steady rain.

Upon encountering severe turbulence, which flight condition should the pilot attempt to maintain?

A. Constant altitude and airspeed.

B. Constant angle of attack.

C. Level flight attitude.

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

A. Roll cloud.

B. Continuous updraft.

C. Frequent lightning.

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

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

B. Moist, tropical air moving over cold, offshore water.

C. The movement of cold air over much warmer water.

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

A. Freezing precipitation.

B. Thunderstorms.

C. Fog or low clouds.

In which situation is advection fog most likely to form?

A. A warm, moist air mass on the windward side of mountains.

B. An air mass moving inland from the coast in winter.

C. A light breeze blowing colder air out to sea.

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

A. Radiation fog and ice fog.

B. Steam fog and ground fog.

C. Advection fog and upslope fog.

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

A. Rain-induced fog.

B. Upslope fog.

C. Steam fog.

Which is considered to be the most hazardous condition when soaring in the vicinity of thunderstorms?

A. Static electricity.

B. Lightning.

C. Wind shear and turbulence.

Which weather phenomenon is always associated with a thunderstorm?

A. Lightning.

B. Heavy rain.

C. Hail.

Refer to the excerpt from the following METAR report: KTUS 08004KT 4SM HZ 26/04 A2995 RMK RAE36 At approximately what altitude AGL should bases of convective-type cumuliform clouds be expected?

A. 4,400 feet.

B. 8,800 feet.

C. 17,600 feet.

The wind system associated with a low-pressure area in the Northern Hemisphere is

A. an anticyclone and is caused by descending cold air.

B. a cyclone and is caused by Coriolis force.

C. an anticyclone and is caused by Coriolis force.

What prevents air from flowing directly from high-pressure areas to low-pressure areas?

A. Coriolis force.

B. Surface friction.

C. Pressure gradient force.

Which is true with respect to a high- or low-pressure system?

A. A high-pressure area or ridge is an area of rising air.

B. A low-pressure area or trough is an area of descending air.

C. A high-pressure area or ridge is an area of descending air.

When conditionally unstable air with high-moisture content and very warm surface temperature is forecast, one can expect what type of weather?

A. Strong updrafts and stratonimbus clouds.

B. Restricted visibility near the surface over a large area.

C. Strong updrafts and cumulonimbus clouds.

What is the standard temperature at 10,000 feet?

A. -5 °C.

B. -15 °C.

C. +5 °C.

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

A. a heat exchange.

B. the movement of air.

C. a pressure differential.

Which conditions are favorable for the formation of a surface based temperature inversion?

A. Clear, cool nights with calm or light wind.

B. Area of unstable air rapidly transferring heat from the surface.

C. Broad areas of cumulus clouds with smooth, level bases at the same altitude.

What are the standard temperature and pressure values for sea level?

A. 15 °C and 29.92 inches Hg.

B. 59 °F and 1013.2 inches Hg.

C. 15 °C and 29.92 Mb.

GIVEN: Pressure altitude 12,000 ft True air temperature +50 °F From the conditions given, the approximate density altitude is

A. 11,900 feet.

B. 14,130 feet.

C. 18,150 feet.

Why does the wind have a tendency to flow parallel to the isobars above the friction level?

A. Coriolis force tends to counterbalance the horizontal pressure gradient.

B. Coriolis force acts perpendicular to a line connecting the highs and lows.

C. Friction of the air with the Earth deflects the air perpendicular to the pressure gradient.

While flying cross-country, in the Northern Hemisphere, you experience a continuous left crosswind which is associated with a major wind system. This indicates that you

A. are flying toward an area of generally unfavorable weather conditions.

B. have flown from an area of unfavorable weather conditions.

C. cannot determine weather conditions without knowing pressure changes.

In the Northern Hemisphere, the wind is deflected to the

A. right by Coriolis force.

B. right by surface friction.

C. left by Coriolis force.

With regard to windflow patterns shown on surface analysis charts; when the isobars are

A. close together, the pressure gradient force is slight and wind velocities are weaker.

B. not close together, the pressure gradient force is greater and wind velocities are stronger.

C. close together, the pressure gradient force is greater and wind velocities are stronger.

When flying into a low-pressure area in the Northern Hemisphere, the wind direction and velocity will be from the

A. left and decreasing.

B. left and increasing.

C. right and decreasing.

What causes wind?

A. The Earth's rotation.

B. Air mass modification.

C. Pressure differences.

Ice pellets encountered during flight normally are evidence that

A. a warm front has passed.

B. a warm front is about to pass.

C. there are thunderstorms in the area.

Virga is best described as

A. streamers of precipitation trailing beneath clouds which evaporates before reaching the ground.

B. wall cloud torrents trailing beneath cumulonimbus clouds which dissipate before reaching the ground.

C. turbulent areas beneath cumulonimbus clouds.

Moisture is added to a parcel of air by

A. sublimation and condensation.

B. evaporation and condensation.

C. evaporation and sublimation.

What is indicated if ice pellets are encountered at 8,000 feet?

A. Freezing rain at higher altitude.

B. You are approaching an area of thunderstorms.

C. You will encounter hail if you continue your flight.

Which is true regarding actual air temperature and dewpoint temperature spread? The temperature spread

A. decreases as the relative humidity decreases.

B. decreases as the relative humidity increases.

C. increases as the relative humidity increases.

What is the approximate base of the cumulus clouds if the temperature at 2,000 feet MSL is 10 °C. and the dewpoint is 1 °C?

A. 3,000 feet MSL.

B. 4,000 feet MSL.

C. 6,000 feet MSL.

If clouds form as a result of very stable, moist air being forced to ascend a mountain slope, the clouds will be

A. cirrus type with no vertical development or turbulence.

B. cumulus type with considerable vertical development and turbulence.

C. stratus type with little vertical development and little or no turbulence.

What determines the structure or type of clouds which will form as a result of air being forced to ascend?

A. The method by which the air is lifted.

B. The stability of the air before lifting occurs.

C. The relative humidity of the air after lifting occurs.

The formation of either predominantly stratiform or predominantly cumuliform clouds is dependent upon the

A. source of lift.

B. stability of the air being lifted.

C. temperature of the air being lifted.

What type weather can one expect from moist, unstable air, and very warm surface temperatures?

A. Fog and low stratus clouds.

B. Continuous heavy precipitation.

C. Strong updrafts and cumulonimbus clouds.

What are the characteristics of stable air?

A. Good visibility; steady precipitation; stratus clouds.

B. Poor visibility; steady precipitation; stratus clouds.

C. Poor visibility; intermittent precipitation; cumulus clouds.

From which measurement of the atmosphere can stability be determined?

A. Atmospheric pressure.

B. The ambient lapse rate.

C. The dry adiabatic lapse rate.

Which would increase the stability of an air mass?

A. Warming from below.

B. Cooling from below.

C. Decrease in water vapor.

Which would decrease the stability of an air mass?

A. Warming from below.

B. Cooling from below.

C. Decrease in water vapor.

Which cloud types would indicate convective turbulence?

A. Cirrus clouds.

B. Nimbostratus clouds.

C. Towering cumulus clouds.

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

A. unstable, dry air.

B. stable, moist air.

C. unstable, moist air.

Which are characteristics of a cold air mass moving over a warm surface?

A. Cumuliform clouds, turbulence, and poor visibility.

B. Cumuliform clouds, turbulence, and good visibility.

C. Stratiform clouds, smooth air, and poor visibility.

Which combination of weather-producing variables would likely result in cumuliform-type clouds, good visibility, and showery rain?

A. Stable, moist air and orographic lifting.

B. Unstable, moist air and orographic lifting.

C. Unstable, moist air and no lifting mechanism.

Which is true regarding a cold front occlusion? The air ahead of the warm front

A. is colder than the air behind the overtaking cold front.

B. is warmer than the air behind the overtaking cold front.

C. has the same temperature as the air behind the overtaking cold front.

Hazardous wind shear is commonly encountered

A. near warm or stationary frontal activity.

B. when the wind velocity is stronger than 35 knots.

C. in areas of temperature inversion and near thunderstorms.

What is an important characteristic of wind shear?

A. It is present at only lower levels and exists in a horizontal direction.

B. It is present at any level and exists in only a vertical direction.

C. It can be present at any level and can exist in both a horizontal and vertical direction.

Which situation would most likely result in freezing precipitation? Rain falling from air which has a temperature of

A. 32 °F or less into air having a temperature of more than 32 °F.

B. 0 °C or less into air having a temperature of 0 °C or more.

C. more than 32 °F into air having a temperature of 32 °F or less.

The most severe weather conditions, such as destructive winds, heavy hail, and tornadoes, are generally associated with

A. slow-moving warm fronts which slope above the tropopause.

B. squall lines.

C. fast-moving occluded fronts.

Of the following, which is accurate regarding turbulence associated with thunderstorms?

A. Outside the cloud, shear turbulence can be encountered 50 miles laterally from a severe storm.

B. Shear turbulence is encountered only inside cumulonimbus clouds or within a 5-mile radius of them.

C. Outside the cloud, shear turbulence can be encountered 20 miles laterally from a severe storm.

Which statement is true regarding squall lines?

A. They are always associated with cold fronts.

B. They are slow in forming, but rapid in movement.

C. They are nonfrontal and often contain severe, steady-state thunderstorms.

Select the true statement pertaining to the life cycle of a thunderstorm.

A. Updrafts continue to develop throughout the dissipating stage of a thunderstorm.

B. The beginning of rain at the Earth's surface indicates the mature stage of the thunderstorm.

C. The beginning of rain at the Earth's surface indicates the dissipating stage of the thunderstorm.

What visible signs indicate extreme turbulence in thunderstorms?

A. Base of the clouds near the surface, heavy rain, and hail.

B. Low ceiling and visibility, hail, and precipitation static.

C. Cumulonimbus clouds, very frequent lightning, and roll clouds.

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

A. Roll cloud.

B. Continuous updraft.

C. Beginning of rain at the surface.

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

A. The start of rain.

B. The appearance of an anvil top.

C. Growth rate of cloud is maximum.

Hail is most likely to be associated with

A. cumulus clouds.

B. cumulonimbus clouds.

C. stratocumulus clouds.

Which statement is true concerning the hazards of hail?

A. Hail damage in horizontal flight is minimal due to the vertical movement of hail in the clouds.

B. Rain at the surface is a reliable indication of no hail aloft.

C. Hailstones may be encountered in clear air several miles from a thunderstorm.

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

A. Mature.

B. Developing.

C. Dissipating.

Advection fog has drifted over a coastal airport during the day. What may tend to dissipate or lift this fog into low stratus clouds?

A. Nighttime cooling.

B. Surface radiation.

C. Wind 15 knots or stronger.

With respect to advection fog, which statement is true?

A. It is slow to develop, and dissipates quite rapidly.

B. It forms almost exclusively at night or near daybreak.

C. It can appear suddenly during day or night, and it is more persistent than radiation fog.

A situation most conducive to the formation of advection fog is

A. a light breeze moving colder air over a water surface.

B. an air mass moving inland from the coastline during the winter.

C. a warm, moist air mass settling over a cool surface under no-wind conditions.

In what ways do advection fog, radiation fog, and steam fog differ in their formation or location?

A. Radiation fog is restricted to land areas; advection fog is most common along coastal areas; steam fog forms over a water surface.

B. Advection fog deepens as windspeed increases up to 20 knots; steam fog requires calm or very light wind; radiation fog forms when the ground or water cools the air by radiation.

C. Steam fog forms from moist air moving over a colder surface; advection fog requires cold air over a warmer surface; radiation fog is produced by radiational cooling of the ground.

Fog produced by frontal activity is a result of saturation due to

A. nocturnal cooling.

B. adiabatic cooling.

C. evaporation of precipitation.

Which in-flight hazard is most commonly associated with warm fronts?

A. Advection fog.

B. Radiation fog.

C. Precipitation-induced fog.

Which feature is associated with the tropopause?

A. Constant height above the Earth.

B. Abrupt change in temperature lapse rate.

C. Absolute upper limit of cloud formation.

Which is true regarding the development of convective circulation?

A. Cool air must sink to force the warm air upward.

B. Warm air is less dense and rises on its own accord.

C. Warmer air covers a larger surface area than the cool air; therefore, the warmer air is less dense and rises.

Which is generally true when comparing the rate of vertical motion of updrafts with that of downdrafts associated with thermals?

A. Updrafts and downdrafts move vertically at the same rate.

B. Downdrafts have a slower rate of vertical motion than do updrafts.

C. Updrafts have a slower rate of vertical motion than do downdrafts.

Select the true statement concerning thermals.

A. Thermals are unaffected by winds aloft.

B. Strong thermals have proportionately increased sink in the air between them.

C. A thermal invariably remains directly above the surface area from which it developed.

(Refer to figure 24 .) Determine the density altitude. Airport elevation 3,795 ft OAT 24 °C Altimeter setting 29.70 inches Hg

A. 5,900 feet.

B. 5,700 feet.

C. 4,000 feet.

In what part of the atmosphere does most weather occur?

A. Tropopause.

B. Troposphere.

C. Stratosphere.

If the air temperature is +6 °C at an elevation of 700 feet and a standard (average) temperature lapse rate exists, what will be the approximate freezing level?

A. 6,700 feet MSL.

B. 3,700 feet MSL.

C. 2,700 feet MSL.

The most frequent type of ground- or surface-based temperature inversion is that produced by

A. terrestrial radiation on a clear, relatively still night.

B. warm air being lifted rapidly aloft in the vicinity of mountainous terrain.

C. the movement of colder air under warm air or the movement of warm air over cold air.

Which is the primary driving force of weather on the Earth?

A. The Sun.

B. Coriolis.

C. Rotation of the Earth.

As density altitude increases, which will occur if a constant indicated airspeed is maintained in a nowind condition?

A. True airspeed increases; groundspeed decreases.

B. True airspeed decreases; groundspeed decreases.

C. True airspeed increases; groundspeed increases.

An altimeter indicates 1,850 feet MSL when set to 30.18. What is the approximate pressure altitude?

A. 1,590 feet.

B. 1,824 feet.

C. 2,110 feet.

In the Northern Hemisphere, a pilot making a long distance flight from east to west would most likely find favorable winds associated with high- and low-pressure systems by flying to the

A. north of a high and a low.

B. north of a high and to the south of a low.

C. south of a high and to the north of a low.

Which statement is true regarding high- or low-pressure systems?

A. A high-pressure area or ridge is an area of rising air.

B. A low-pressure area or trough is an area of rising air.

C. A high-pressure area is a trough of descending air.

What causes wind?

A. Coriolis force.

B. Pressure differences.

C. The rotation of the Earth.

Which is an operational consideration regarding actual air temperature and dewpoint temperature spread?

A. The temperature spread decreases as the relative humidity decreases.

B. The temperature spread decreases as the relative humidity increases.

C. The temperature spread increases as the relative humidity increases.

Streamers of precipitation trailing beneath clouds but evaporating before reaching the ground are known as

A. virga.

B. sublimation.

C. condensation trails.

Which precipitation type usually indicates freezing rain at higher altitudes?

A. Snow.

B. Hail.

C. Ice pellets.

At approximately what altitude above the surface would you expect the base of cumuliform clouds if the surface air temperature is 77 °F and the dewpoint is 53 °F?

A. 9,600 feet AGL.

B. 8,000 feet AGL.

C. 5,500 feet AGL.

From which measurement of the atmosphere can stability be determined?

A. Ambient lapse rate.

B. Atmospheric pressure.

C. Difference between standard temperature and surface temperature.

If clouds form as a result of very stable, moist air being forced to ascend a mountain slope, the clouds will be

A. cirrus type with no vertical development or turbulence.

B. cumulonimbus with considerable vertical development and heavy rains.

C. stratus type with little vertical development and little or no turbulence.

Which middle level clouds are characterized by rain, snow, or ice pellets posing a serious icing problem if temperatures are near or below freezing?

A. Nimbostratus.

B. Altostratus lenticular.

C. Altocumulus castellanus.

What type weather can one expect from moist, unstable air and very warm surface temperature?

A. Fog and low stratus clouds.

B. Continuous heavy precipitation.

C. Strong updrafts and cumulonimbus clouds.

Consider the following air mass characteristics: 1. Cumuliform clouds. 2. Stable lapse rate. 3. Unstable lapse rate. 4. Stratiform clouds and fog. 5. Smooth air (above the friction level) and poor visibility. 6. Turbulence up to about 10,000 feet and good visibility except in areas of precipitation. A moist air mass, which is colder than the surface over which it passes, frequently has which of the above characteristics?

A. 1, 3, and 6.

B. 3, 4, and 5.

C. 2, 4, and 5.

Cool air moving over a warm surface is generally characterized by

A. instability and showers.

B. stability, fog, and drizzle.

C. instability and continuous precipitation.

What type weather is associated with an advancing warm front that has moist, unstable air?

A. Stratiform clouds, lightning, steady precipitation.

B. Cumuliform clouds, smooth air, steady precipitation.

C. Cumuliform clouds, turbulent air, showery-type precipitation.

Low-level wind shear, which results in a sudden change of wind direction, may occur

A. after a warm front has passed.

B. when surface winds are light and variable.

C. when there is a low-level temperature inversion with strong winds above the inversion.

Which condition could be expected if a strong temperature inversion exists near the surface?

A. Strong, steady downdrafts and an increase in OAT.

B. A wind shear with the possibility of a sudden loss of airspeed.

C. An OAT increase or decrease with a constant wind condition.

The most rapid accumulation of clear ice on an aircraft in flight may occur with temperatures between 0 °C to -15 °C in

A. cumuliform clouds.

B. stratiform clouds.

C. any clouds or dry snow.

Which is an operational consideration regarding aircraft structural icing?

A. It is unnecessary for an aircraft to fly through rain or cloud droplets for structural ice to form.

B. Clear ice is most likely to form on an airplane when flying through stratified clouds or light drizzle.

C. In order for structural ice to form, the temperature at the point where moisture strikes the aircraft must be 0 °C (32 °F) or colder.

Select the true statement pertaining to the life cycle of a thunderstorm.

A. The initial stage of a thunderstorm is always indicated by the development of a nimbus cloud.

B. The beginning of rain at the Earth's surface indicates the mature stage of the thunderstorm.

C. The beginning of rain at the Earth's surface indicates the dissipating stage of the thunderstorm.

What are the minimum requirements for the formation of a thunderstorm?

A. Sufficient moisture and a lifting action.

B. Sufficient moisture, an unstable lapse rate, and lifting action.

C. Towering cumulus clouds, sufficient moisture, and a frontal zone.

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

A. Frequent lightning.

B. Continuous updrafts.

C. Beginning of rain at the surface.

Consider the following statements regarding hail as an in-flight hazard and select those which are correct. 1. There is a correlation between the visual appearance of thunderstorms and the amount of hail within them. 2 Large hail is most commonly found in thunderstorms which have strong updrafts and large liquid water content. 3 Hail may be found at any level within a thunderstorm but not in the clear air outside of the storm cloud. 4 Hail is usually produced during the mature stage of the thunderstorm's lifespan. 5 Hailstones may be thrown upward and outward from a storm cloud for several miles. The true statements are:

A. 2, 4, and 5.

B. 1, 2, and 3.

C. 1, 2, 4, and 5.

A squall line is usually associated with a

A. stationary front.

B. fast-moving cold front.

C. fast-moving warm front.

Radiation fog is most likely to occur under what conditions?

A. Warm, moist air being forced upslope by light winds resulting in the air being cooled and condensed.

B. High humidity during the early evening, cool cloudless night with light winds, and favorable topography.

C. Low temperature/dewpoint spread, calm wind conditions, the presence of hydroscopic nuclei, low overcast, and favorable topography.

With respect to advection fog, which statement is true?

A. It forms almost exclusively at night or near daybreak.

B. It forms when unstable air is cooled adiabatically.

C. It can appear suddenly during day or night, and it is more persistent than radiation fog.

Advection fog is formed as a result of

A. moist air moving over a colder surface.

B. the addition of moisture to a mass of cold air as it moves over a body of water.

C. the ground cooling adjacent air to the dewpoint temperature on clear, calm nights.

One condition necessary for the formation of fog is

A. calm air.

B. visible moisture.

C. high relative humidity.

Which in-flight hazard is most commonly associated with warm fronts?

A. Ground fog.

B. Advection fog.

C. Precipitation-induced fog.

Which is true regarding the development of convective circulation?

A. Cool air must sink to force the warm air upward.

B. Warm air is less dense and rises on its own accord.

C. Cool air surrounding convective circulation sinks at a greater rate than the warmer air rises (within the thermal), thus forcing the warmer air upward.

What is the expected duration of an individual microburst?

A. One microburst may continue for as long as an hour.

B. Five minutes with maximum winds lasting approximately 2 to 4 minutes.

C. Seldom longer than 15 minutes from the time the burst strikes the ground until dissipation.

Maximum downdrafts in a microburst encounter may be as strong as

A. 6,000 feet per minute.

B. 4,500 feet per minute.

C. 1,500 feet per minute.

How long do the maximum intensity winds last in an individual microburst?

A. 2 to 4 minutes.

B. 5 to 10 minutes.

C. 15 minutes.