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80 Cards in this Set
- Front
- Back
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the primary cause of all changes in the earth's weather is
a. variation of solar energy received by the earth's regions b. changes in air pressure over the earth's surface c. movement of the airmasses |
A
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which force, in the northern hemisphere, acts at a right angle to the wind and deflects it to the right until parallel to the isobars?
a. centrifugal b. pressure gradient c. coriolis |
C
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what relationship exists between the winds at 2000 ft above the surface and the surface winds?
a. the winds at 2000 ft and the surface winds flow in the same direction, but the surface winds are weaker due to friction b. the winds at 2000 ft tend to parallel the isobars while the surface winds cross the isobars at an angle toward lower pressure and are weaker c. the surface winds tend to veer to the right of the winds at 2000 ft and are usually weaker |
B
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winds at 5000 ft agl on a particular flight are southwesterly while most of the surface winds are southerly. this difference in direction is primarily due to
a. a stronger pressure gradient at higher altitudes b. friction between wind and the surface c. stronger coriolis force at the surface |
B
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what causes surface winds to flow across the isobars at an angle rather than parallel to the isobars?
a coriolis force b. surface friction c. the greater density of the air at the surface |
B
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an air mass is a body of air that
a. has similar cloud formations associated with it b. creates a wind shift as it moves across the earth's surface c. covers an extensive area and has fairly uniform properties of temp and moisture |
C
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a characteristic of the atmosphere is
a. an overall decrease of temp with an increase in altitude b. a relatively even base altitude of approx 35000 ft c. relatively small changes in temp with an increase in altitude |
C
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a jet stream is defined as wind
a. 30kt + b. 40kt + c. 50kt + |
C
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the average height of the troposphere is the middle latitudes is
a. 20000 b. 25000 c. 37000 |
C
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the strength and location of the jet stream is normally
a. stronger and farther north in the winter b. weaker and farther north in summer c. stronger and father north in the summer |
B
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which feature is associated with the tropopause?
a. absence of wind and turbulent conditions b. absolute upper limit of cloud formations c. abrupt change in temp lapse rate |
C
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which weather phenomenon is always associated with the passage of a frontal system?
a. a wind change b. an abrupt decrease in pressure c. clouds, either ahead or behind the front |
A
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which is a characteristic of low-level wind shear as it relates to frontal activity?
a. with a warm front, the most critical period is before the front passes the airport b. with a cold front, the most critical period is just before the front passes the airport c. turbulence will always exist in wind-shear conditions |
A
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frontal waves normally form on
a. slow moving cold fronts or stationary fronts b. slow moving warm fronts and strong occluded fronts c. rapodly moving cold fronts or warm fronts |
A
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where do squall lines most often develop?
a. in an occluded front b. in a cold air mass c. ahead of a cold fronts |
C
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which are characteristics of an unstable 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 |
B
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what are the characteristics of stable air?
a. good visibility, steady precipitation, and stratus-type clouds b. poor visibility, intermittent precipitation, and cumulus-type clouds. c. poor visibility, steady precipitation, and stratus-type clouds |
C
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what type of clouds can be excepted when an unstable air mass is forced to ascend a mountain slope?
a. layered clouds with little vertical development b. stratified clouds with considerable associated turbulence c. clouds with extensive vertical development |
C
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which is a characteristic of stable air?
a. fair weather cumulus clouds b. stratiform clouds c. unlimited visibility |
B
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the general characteristics of unstable air are
a. good visibility, showery precipitation, and cumuliform-type clouds b. good visibility, steady precipitation, and stratiform-type clouds c. poor visibility, intermittent precipitation, and cumuliform-type clouds |
A
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what type of clouds will be formed if very stable moist air is forced up?
a. first stratified clouds and then vertical clouds b. vertical clouds with increasing height c. stratified clouds with little vertical development |
C
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steady precipitation, in contrast to showers, preceding a front is an indication of
a. stratiform clouds with moderate turbulence b. cumuliform clouds with little of no turbulence c. stratiform clouds with little of no turbulence |
C
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what enhances the growth rate of precipitation?
a advective action b. upward currents c. cyclonic movement |
B
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which of the following combinations ofweather producing variables would likely result cumuliform-type clouds, good visibility, rain showers, and possible clear-type icing clouds?
a. unstable, moist air, and no lifting mechanism b. stable, dry air, and orographic lifting c. unstable, moist air, and orographic lifting |
C
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what determines the structure of type of clouds which 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 amout of condensation nuclei present after lifting occurs |
B
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stability can be determined from which measurement of the atmosphere?
a. low-level winds b. ambient lapse rate c. atmosphere pressure |
B
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what are some characteristics of unstable air?
a. nimbostratus clouds and good surface visibility b. turbulence and poor surface visibility c. turbulence and good surface visibility |
C
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unsaturated air flowing up slope will cool at the rate of approx (dry adiabatic lapse rate)
a. 3C per 1000ft b. 2C per 1000ft c. 2.5C per 1000ft |
A
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what feature is associated with a temp inversion?
a. a stable layer of air b. an unstable layer of air c. air mass thunderstorms |
A
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which weather conditions should be expected beneath a low-level temp inversion layer when the relative humidity is high?
a. smooth air and poor visibility due to fog, haze, or low clouds b. light wind shear and poor visibility due haze and light rain c. turbulent air and poor visibility due to fog, low stratus-type clouds, and showery precipitation |
A
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a temp inversion will normally form only
a. in stable air b. in unstable air c. when a stratiform layer merges with a cumuliform mass |
A
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a common type of ground or surface based temp inversion is that which is produced by
a. warm air being lifted rapidly aloft in the vicinity of mountainous terrain b. the movement of colder iar over warm air. or the movement of the warm air under cold air c. ground radiation of clear, cool nights when the wind is light |
C
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which conditions are favorable for the formation of radiation fog?
a. moist air moving over colder ground or water b. cloudy sky and a light wind moving saturated warm air over a cool surface c. clear sky, little of no wind, small temp/ dew point spread, and over a land surface |
C
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what situation is most conductive to the formation of radiation fog?
a. warm, moist air over low, flatland areas on clear, clam nights b. moist, tropical air moving over cold, offshore water c. the movement of cold air over much warmer water |
A
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the most frequent type of ground or surface based temp inversion is that produced by
a. radiation on a clear, relatively still night b. warm air being lifted rapidly aloft on the vicinity of mountainous terrain c. the movement of colder air under warm air, or the movement of warm air over cold air |
A
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what types of fog depend upon a wind order to exist?
a. steam fog and down slope fog b. precipitation -induced fog and ground fog c. advection fog and up slope fog |
C
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in what localities is advection fog most likely to occur?
a. coastal areas b. mountain slopes c. level inland areas |
A
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in which situation is advection fog most likely to form?
a. an air mass moving inland from the coast in winter b. a light breeze blowing colder air out to sea c. warm, moist air settling over a warmer surface under no-wind conditions |
A
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fog is usually prevalent in industrial areas because of
a. atmospheric stabilization around cities b. an abundance of condensation nuclei from combustion products c. increased temp due to industry heating |
B
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which weather condition can be excepted when moist air flows from a relatively warm surface to a colder surface?
a. increased visibility b. convective turbulence due to surface heating c. fog |
C
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under which conditions does advection fog usually form?
a. moist air moving over colder ground or water b. warm, moist air settling over a cool surface under no wind conditions c. a land breeze blowing a cold air mass over a warm water current |
A
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the amount of water vapor which air can hold depends on
a. relative humidity b. air temp c. stability of air |
B
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clouds, fog, or dew will always form when
a. water vapor condenses b. water vapor is present c. stability of iar |
A
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to which meteorological condition does the term "dew point" refer?
a. the temp to which air must be cooled to become saturated b. the temp at which condensation and evap are equal c. the temp at which dew ill always form |
A
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which conditions result in the formation of frost?
a. the temp of the collecting surface is at or below freezing and small droplets of moisture are falling b. when dew forms and the temp is below freezing c. temp of the collecting surface is below the dew point of the surrounding air and the dew point is colder than zero |
C
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what are the four families of clouds?
a. stratus, cumulus, nimbus, and cirrus b. clouds formed by updrafts, fronts, cooling layers if air, and precipitation into warm air c. high, middle, low, and those with extensive vertical development |
C
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which family of clouds is least likely to contribute to structural icing on an aircraft?
a. low clouds b. high clouds c. clouds with extensive vertical development |
B
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the presence of standing lenticular altocumulous clouds is a good indication of
a. a jetstream b. very strong turbulunce c. heavy icing conditions |
B
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the suffix "nimbus", used in naming clouds, means a
a. cloud with extensive vertical development b. rain cloud c. dark massive, towering cloud |
B
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standing lenticular clouds, in mountainous areas, indicate
a. an inversion b. unstable air c. turbulence |
C
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which clouds have the greatest turbulence?
a. towering cumulus b. cumulonimbus c. altocumulus castellanus |
B
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a high cloud is composed mostly of
a. ozone b. condensation nuclei c. ice crystals |
C
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fair weather cumulus clouds often indicate
a. turbulence at and below the cloud level b. poor visibility c. smooth flying conditions |
A
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what are the requirements for the formation of a t-storm?
a cumulus cloud with sufficient moisture b. a cumulus cloud with sufficient moisture and an inverted lapse rate c. sufficient moisture, an unstable lapse rate, and a lifting action |
C
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what is an indication that downdrafts have developed and the t-storm cell has entered the mature stage?
a. the anvil top has completed its development b. precipitation begins to fall from the cloud base c. a gust front forms |
B
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which procedure is recommended if a pilot should unintentionally penetrate embedded t-storm activity?
a. reverse aircraft heading or proceed toward an area of known VFR b. reduce airspeed to maneuvering speed and maintain a constant altitude c. set power for recommended turbulence penetration airspeed and attempt to maintain a level flight attitude |
C
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which t-storm generally produce the most severe conditions, such as heavy hail and destructive winds?
a. warm front b. squall line c. air mass |
B
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which weather phenomenon is always associated with a t-storm?
a. lightning b. heavy rain showers c. supercooled raindrops |
A
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during the life cycle of a t-storm, which stage is characterized predominately by down drafts?
a. cumulus b. dissipating c. mature |
B
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is squalls are reported at your destination, what wind conditions should you anticipate?
a. sudden increase in wind speed of at least 16 kt rising to 22 kt or more, lasting for at least 1 min b. peak gusts of at least 35 kt for a sustained period of 1 min or longer c. rapid variation on wind direction of at lest 20 degrees and changes in speed of at least 10 kt btw peaks and lulls |
A
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what is indicated by the term "embedded t-storms"?
a. severe t-storms are embedded within a squall line b. t-storms are predicted to develop in a stable air mass c. t-storms are obscured by massive could layers and cannot be seen |
C
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which weather phenomenon signals the beginning of the mature stage of a t-storm?
a. the start of rain at the surface b. growth rate of cloud is maximum c. strong turbulence in the cloud |
A
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which is true regarding the use of airborne weather-avoidance radr for the recognition of certain weather conditions?
a. the radarscope provides no assurance of avoiding instrument weather condition b. the avoidance of hail is assured when flying between and just clear of the most intense echoes c. the clear area btw intense echoes indicates that visual sighting of storms can be maintained when flying btw the echoes |
A
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in which meteorological environment is aircraft structural icing most likely to have the highest rate of accumulation?
a. cumulonimbus clouds b. high humidity and freezing temps c. freezing rain |
C
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test data indicates that ice, snow, of frost having a thickness and roughness similar to medium or course sandpaper on the leading edge and upper surface of an airfoil can
a. reduce lift by as much as 50% and increase drag by as much as 50% b. increase drag and reduce lift by as much as 25% c. reduce lift by as much as 30% and increase drag by 40% |
C
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which precipitation type normally indicates freezing rain at higher altitudes?
a. snow b. hail c. ice pellets |
C
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what is an operational consideration if you fly into rain which freezes on impact?
a. you have flown into an area of t-storms b. temps are above freezing at some higher altitude c. you have flown through a cold front |
B
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what temp condition is indicated if wet snow is encountered at your flight altitude?
a. the temp is above freezing at your altitude b. the temp is below freezing at your altitude c. you are flying from a warm air mass into a cold air mass |
A
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the presence of ice pellets at the surface is evidence that
a. there are t-storms in the area b. a cold front has passed c. there is freezing rain at a higher alt |
C
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why is frost considered hazardous to flight ops?
a. frost changes the basic aerodynamic shape of the airfoil b. frost decreases control effectiveness c. frost causes early airflow separation resulting in a loss of lift |
C
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if the air temp is +8C at an elevation of 1350ft and a standard temp lapse rate exists, what will be the approx freezing level?
a. 3350 b. 5350 c. 9350 |
B
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what is an important characteristic of wind shear?
a. it is an atmospheric condition that is associated exclusively with zones of convergence b. the coriolis phenomenon in both high and low level air masses is the principal generating force c. it is an atmospheric condition that may be associated with a low level temp inversion, a jet stream, or a frontal zone |
C
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a pilot reporting turbulence that momentarily causes slight, erratic changes in altitude and/or attitude should report it as
a. light turbulence b. moderate turbulence c. light chop |
A
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what is an important characteristic of wind shear?
a. it is primarily associated with the lateral vortices generated by t-storms b. it usually exists only in the vicinity of t-storms, but may be found near a strong temp inversion c. it may be associated with either a wind shift of a wind speed gradient at any level in the atmosphere |
C
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where can wind sheer associated with a thunderstorm be found?
a. in front of the t-storm cell (anvil side) and on the right side of the cell b. in front of the t-storm cell and directly under the cell c. on all sides of the t-storm and directly under the cell |
C
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where does wind shear occur?
a. exclusively in t-storms b. wherever there is an abrupt decrease in pressure and/or temp c. with either wind shift of a wind speed gradient at any level in the atmosphere |
C
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hazardous wind shear is commonly encountered near the ground
a. during periouds when the wind velocity is stronger than 35 kt b. during periods when the wind velocity is stronger than 35 kt and near mountain valleys c. during periods of strong temp inversion and near t-storms |
C
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an aircraft that encounters a headwind of 45 kt, within a microburst, may expect a total shear across the mircoburst of
a. 40kt b. 80kt c. 90kt |
C
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max downdrafts in a microburst encounter may be as strong as
a. 8000 fpm b. 7000 fpm c. 6000 fpm |
C
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what is the expected duration of an individual microburst?
a. two min with max winds lasting approx 1 min b. one microburst may continue for as long as 2-4 hours c. seldom longer than 15 minutes from the time to burst strikes the ground until dissipation |
C
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