Weather and weather services
What is a typical characteristic of a stable air mass? cumuliform clouds showery precip continuous precip
continuous precip
What feature is associated with the cumulus stage of a thunderstorm?
continuous updrafts
The most rapid accumulation of clear ice on an aircraft in flight may occur with temperatures between 0C to -15C in... cumuliform clouds stratiform clouds any clouds or dry snow
cumuliform clouds
A moist, unstable air mass is characterized by...
cumuliform clouds and showery precip
What type weather is associated with an advancing warm front that has moist, unstable air?
cumuliform clouds, turbulent air, showery type precip
Hail, an in flight hazard, is most likely to be associated with... (cloud type)
cumulonimbus clouds
Which type of cloud is associated with voilent turbulence and a tendency toward the production of funnel clouds?
cumulonimbus mamma
The windflow around a low pressure is...
cyclonic
An aircraft is flying at a constant power setting and constant indicated altitude. If the outside air tempertuare decrease, true airspeed will...
decrease, and true altitude will decrease
A squall line is usually associated with a...
fast moving cold front
When warm air moves over a cold lake, what weather phenomenon is likely to occur on the leeward side of the lake? fog showers cloudiness
fog
Winds at 5,000 feet AGL on a particular flight are southwesterly while most of the surface winds are southerly. This difference in direection is primarily due to...
friction between the wind and the surface
Which precip type usually indicates freezing rain at higher altitudes?
ice pellets
An aircraft is flying at a constant power setting and constant indicated altitude. If the outside air temperature increases, true airspeed will...
increase and true altitude will increase
Cool air moving over a warm surface is generally characterized by... instability and showers stability, fog, and drizzle instability and continuous precip
instability and showers
An increase in temperature with an increase in altitude...
is an indication of an inversion
When flying low over hilly terrain, ridges, or mountain ranges, the greatest potential danger from turbulent air currents will usually be encountered on the... leeward side when flying with the wind leeward side when flying into the wind windward side when flying into the wind
leeward side when flying into the wind
When flying from a high to a low pressure area in the Northern hemisphere, the wind direction and velocity will be...
left and increasing
Which middle level clouds are characterized by rain, snow, or ice pellets posing a serious icing problem if temperatures are near or below freezing? nimbostratus altostratus lenticular altocumulus castellanus
nimbostratus
The general circulation of air associated with a high pressure area in the Northern Hemisphere is...
outward, downward, and clockwise
Density altitude may be determined by correcting...
pressure altitude for nonstandard temperature
What causes wind?
pressure differences
The radio of the existing water vapor in the air, as compared to the maximum amount that wcould exist at a given temperture is called...
relative humidity
What is the expected duration of an individual microburst?
seldom longer than 15 minutes from the time the burst strikes the ground until dissipation
A moist, cold air mass that is being warmed from below is characterized in part by... fog and drizzle showers and thunderstorms continuous heavy precip
showers and thunderstorms
A moist, warm air mass that is being cooled from below is characterized, in part, by... smooth air cumuliform clouds showers and thunderstorms
smooth air
In the northern hemisphere, a pilot making a long distance flight from east to west would most likley find favorable winds associated with high and low pressure systems by flyign to the...
south of a high and north of a low
The formation of either predominatly stratiform or predominatly cumuliform clouds is dependent upon the...
stability of the air being lifted
Tornadoes are most likely to occur with which type of thunderstorm?
steady state thunderstorms associated with cold fronts or squall lines
If clouds form as a result of very stable, moist air being forced to ascend a mountain slope, the clouds will be...
stratus type with little vertical development and little or no turbulence
What type weather can one expect from moist, unstable air and very warm surface temperature?
strong updrafts and cumulonimbus clouds
What is the process by which ice cna form on a surface directly wfrom water vapor on a cold, clear night?
sublimation
What are the minimum requirements for the formation of a thunderstorm?
sufficient moisture, an unstable lapse rate, and lifting action
Streamers of precip trailing beneath clouds but evaporating before reaching the ground are known as...
virga
A surface inversion can... indicate chance of gusty winds produce poor visibility mean an unstable air mass
2
If a wave were to form on a stationary front running east to west across the US, that portion east of the wave would normally... 1. remain stationary with that portion west of the wave becoming a cold front 2. become a warm front and that portion west of the wave would become a cold front 3. become a cold front and that portion west of the wave would become a warm front
2
Select the true statement pertaining to the life cycle of a thunderstorm 1. the initial stage of a thunderstomr is always indicated bythe development of a nimbus cloud 2. the beginning of rain at the earths surface indicates the mature stage of the thunderstorm 3. the beginning of rain at the earths surface indicates the dissipating stage of the thunderstorm
2
What is a characteristic of stable air? 1. excellent visibility 2. restricted visiblity 3. showery type precip
2
Which condition could be expected if a strong temperature inversion exists near the surface? 1. strong, steady downdrafts and an increase in OAT 2. wind shear with possibility of a sudden loss of airspeed 3. an OAT increase or decrease with constant wind condition
2
Which is an operational consideration regarding actual air temp/dp spread? 1. the temp spread decreases as the relative humidity decreases 2. the temp spread decreases as the relative humidity increases 3. the temp spread increases as the relative humidity increases
2
Which statement is true regarding high or low pressure systems? 1. a high pressure area or ridge is an area of rising air 2. a low pressure area or trough is an area of rising air 3. a high pressure area is a trough of descending air
2
The average lapse rate in the troposphere is...
2 degrees celcius per 1000 feet
How long do the maximum intensity winds last in an individual microburst?
2 to 4 minutes
At approximately what altitude above the surface would you expect the base of cumuliform clouds if the surface air temperature is 77oF and the dewpoint is 53oF?
5,500 feet AGL ( temp/dp spread in F / 4.4 ) x 1,000 = cloud base
What are the standard temperature and pressure values for mean sea level?
59oF and 1013.2mB
Maximum downdrafts in a microburst encounter may be as strong as...
6,000 fpm
If the air temperature is +12C at an elevation of 1,250 feet and a standard temperature lapse rate exists, what will be the approximate freezing level?
7,250 feet
At approimately what altitude above the surface would you expect the base of cumuliform clouds if the surface air temperature is 33C and the dp is 15C?
7200 feet AGL ( temp/dp spread in C / 2.5 ) x 1,000 = cloud base
Low level wind shear, which results in a sudden change of wind direction, may occur... after a warm front has passed when surface winds are light and variable when there is a low level temperature inversion with strong winds above the inversion
when there is a low level temperature inversion with strong winds above the inversion
Hail will most likely be encountered... 1. beneath the anvil cloud of a large cumulonimbus 2. during the dissipating stage of the cumulonimbus 3. above the cumulonimbus couds well above the freezing level
1
The most frequent type of ground or surface based temperature inversion is that produced by... 1. terrestrial radiation on a clear, still night 2. warm air being lifted rapidly aloft in the vicinity of mountainous terrain 3. the movement of colder air under warm air or the movement of warm air over cold air
1
Which statement is true regarding a cold front occlusion? 1. the air ahead of the warm front is warmer than the air behind the overtaking cold front 2. the air ahead of the warm front has the same temp as the air behind the overtaking cold front 3. the air between the warm front and cold front is colder than either the air ahead of the warm front or the air behind the overtaking cold front
1
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 and poor vis 6 turbulent air and good vis A moist air mass, which is colder than the surface over which it passes, frequently has which of the above characteristics?
1, 3, 6
An altimeter indicates 1,850 feet MSL when set to 30.18. What is the approximate pressure altitude?
1,590 feet
Consider the following statements regarding hail as an in flight hazard and select those which are correct. 1. there is correlation between the visual appearance of thunderstorms and the amount of hail within them 2. large hail is most ocmmonly 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 Which statements are true
2, 4, 5
As density altitude increases, which will occur if a constant indicated airspeed is maintained in a no wind condition? 1. TAS increase, gs decreases 2. TAS decreases, gs decreases 3. TAS increases, gs increases
3
Frontal waves normally form on... 1. stationary or occluded fronts 2. slow moving warm front or occluded fronts 3. slow moving cold fronts or stationary fronts
3
The weather condition normally associated with unstable air is... 1. stratiform clouds 2. fair to poor visibility 3. good visiblity, except in blowing sand or snow
3
Which is an operational consideration regarding aircraft structural icing? 1. it is unnecessary for an aircraft ot fly through rain or cloud droplets for structural ice to form 2. clear ice is most likely to form on an airplane when flying through stratified clouds or light drizzle 3. in order for structural icing to form, the temp at the point where moisture strikes the aircraft must be 0C or colder
3
Which statement is true concerning the in-flight hazard of hail? hail is usually produced by altocumulus clouds rain at the surface indicates the absence of hail aloft hailstones may be thrown outward from a storm cloud for several miles
3
If the air temperature is +6C at an elevation of 700 feet and a standard temperature lapse rate exists, what will be the approximate freezing level?
3,700 feet
Which situation would most likely result in freezing rain?
Rain falling form air which has a temperature of more than 0oC into air having a temperature of 0oC or less
Which weather conditions should be expected beneath a low level temperature inversion layer when the relative humidity is high?
Smooth air and poor visibility due to fog, haze, or low clouds
Which is the primary driving force of weather on the Earth?
The sun
From which measurement of the atmosphere can stability be determined?
ambient lapse rate
In what part of the atmosphere does most weather occur?
Troposphere
