Every physical process of weather is accompanied by, or is result of, a
Heat exchange.
What causes variations in altimeter settings between weather reporting points?
Unequal heating of the earth's surface.
The wind at 5000 feet AGL is southwesterly while the surface wind is southerly. This difference in direction is primary due to
Friction between the wind and the surface.
Convective circulation pattern associated with sea breezes are caused by
Cool, dense air moving inland from over the weather.
The most frequent type of ground or surface-based temperature inversión is that which is produced by
Terrestrial radiation on a clear, relatively still night.
What's is meant by the term "dewpoint
The temperature to which air must be cooled to become saturated.
The amount of water which air can hold depends on the
Air temperature.
Clouds, fog, or dew will always form when
Water vapor condenses.
What are the processes by which moisture is added to unsaturated air
Evaporation and sublimation.
If the temperature/dewpoint spread is small and decreasing, and the temperature is 62 degrees Fahrenheit, what type weather is most likely to develop?
Fog or low clouds.
One of the most easily recognize discontinuities across a front is
A change in temperature.
One weather phenomenon which will always occur when flying across a front is change in the
Wind direction.
Which weather conditions should be expected beneath a low-level temperature inversion layer when the relative humidity is high?
Smooth air, poor visibility, fog, haze, or low clouds.
What measurement can be used to determine the stability of the atmosphere?
Actual lapse rate.
What would decrease the stability of an air mass?
Warming from below.
What is a characteristic of stable air?
Stratiform clouds.
What feature is associated with a temperature inversion?
A stable layer of air.
What are characteristics of a moist, unstable air mass?
Cumuliform clouds and showery precipitation.
What are characteristics of unstable air?
Turbulence and good surface visibility.
A stable air mass is most likely to have which characteristic?
Poor surface visibility.
Moist, stable air flowing upslope can be expected to
Produce stratus type clouds.
If an unestable air mass is forced upward, what type clouds can be expected?
Clouds with considerable vertical development and associated turbulence.
Steady precipitation preceding a front is an indication of
Stratiform clouds with little or no turbulence.
The conditions necessary for the formation of cumulonimbus clouds are a lifting action and
Unstable, moist air.
What is the approximate base of the cúmulos clouds if the surface air temperature at 1000 feet MSL is 70 Fahrenheit degrees and the dewpoint is 48 Fahrenheit degrees ?
6000 feet MSL.
At approximately what altitud above the surface would the pilot expect the base of cumuliform clouds if the surface air temperature is 82 Fahrenheit degrees and the dewpoint is 38 Fahrenheit degrees?
10000 feet AGL.
The suffix "nimbus", used in naming clouds, means
A rain cloud.
Clouds are divide into a four families according to their
Height range.
What's coulda have the greatest turbulence?
Cumulonimbus.
an almond or lens-shapped cloud which appears stationary, but which may contains winds of 50 knots or more, is referred to as
A lenticular cloud.
Crest of standing mountain waves may be marked by stationary, lens-shaped clouds known as
Standing lenticular clouds.
What cloud types would indicate convective turbulence?
Towering cumulus clouds.
Possible mountain wave turbulence could be anticipated when winds of 40 knots or greater blow
Across a mountain ridge, and the air is stable.
upon encountering severe turbulence, which flight condition should the pilot attempt to mainttain?
Level flight attitude.
What feature is normally associated with the cumulus stage of thunderstorm?
Continuous updraft.
Which weather phenomenon signals the beginning of the mature stage of thunderstorm?
Precipitation beginning to fall.
What condition are necessary for the formation of thunderstorms?
High humidity, lifting force, and unstable condition.
During the life cycle of thunderstorm, which stage is characterized predominately by downdraft?
Dissipating.
Thunderstorms which generally produce the most intense hazard to aircraft are
Squall line thunderstorms.
Thunderstorms reach their greatest intensity during the
Mature stage.
A nonfrontal, narrow band of active thunderstorms that often develop ahead of a cold front is know as a
Squall 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?
Wind-shear turbulence.
Which weather phenomenon is always associated with a thunderstorm?
Lightning.
Where does wind shear occur?
At all altitudes, in all directions.
When may hazardous wind shear be expected?
In areas of low-level temperature inversion, frontal zones, and clear air turbulence.
A pilot can expect a wind-shear zone in a temperature inversión whenever the windspeed at 2000 to 4000 feet above the surface is at least
25 knots.
The presence of ice pellets at the surface is evidence that there
Is a temperature inversión with freezing rain at a higher altitude.
One in-flight condition necessary for structural icing to form is
Visible moisture.
In which condition environment is aircraft structural ice most likely to have the highest accumulation rate?
Freezing rain.
During cross-country flight you picked up rime icing which you estimate is 1/2" thick on the leading edge of the wing. You are now bellow the clouds at 2000 feet AGL and are approaching your destination airport under VFR. Visibility under the clouds is more than 10 miles, wind at destination airport are 8 knots right down the runway, and the surface temperature is 13 Celsius degrees. You decide to:
Use faster than normal approach and landing speed.
What situation is more conducive to the formation of radiation fog?
Warm, moist air over low, flatland areas on clear, calm nights.
In which situation is advection fog most likely to form?
An air mass moving inland from the coast in winter.
What type of fog depend upon wind in order to exist?
Advection fog and upslope fog.
Low-lever turbulence can occur and icing can become hazardous in which type of fog?
Steam fog.
Which condition result in the formation of frost?
The temperature of the collecting surface is at or below the dewpoint of the adjacent air and the dewpoint is bellow freezing.
How does frost affect the lifting surface of an airplane on takeoff?
Frost may prevent the airplane form becoming airborne at normal takeoff speed
How will frost on the wings of an airplane affect takeoff performance?
Frost will disrupt the smooth flow of air over the wing, adversely affecting its lifting capability.
Why is frost considered hazardous to flight?
Frost spoils the smooth flow of air aver the wings, thereby decreasing lifting capability.