Aviation Weather

Airborne weather radar is installed to help the pilot

avoid severe weather

If a wave were to form on a stationary front running east and west across the United States, that portion east of the wave would normally

become a warm front and that portion west of the wave would become a cold front

One of the most dangerous features of mountain waves is the turbulent areas in and

below rotor clouds

Hail will most likely be encountered

beneath the anvil cloud of a large cumulonimbus

The stability of an air mass can usually be determined by

cloud types and the type of precipitation.

What is a typical characteristic of a stable air mass?

continuous precipitation

Hail, an in-flight hazard, is most likely to be associated with

cumulonimbus clouds

The windflow around a low pressure is

cyclonic

Fog associated with a warm front is a result of saturation due to

evaporation of precipitation

Reflectivity is correlated with intensity terminology for air traffic control (ATC) purposes, with the heaviest intensity referred to as

extreme intensity >50+ dBZ

A squall line is usually associated with a

fast moving cold front

(Refer to Figure 15). The bottom panel on this Convective Outlook Chart indicates

forecast severe thunderstorm areas

Winds at 5,000 feet AGL on a particular flight are southwesterly while most of the surface winds are southerly. This difference in direction is primarily due to

friction between the wind and the surface

Cool air moving over a warm surface is generally characterized by

instability and showers

An increase in temperature with an altitude increase

is indication of an inversion.

(Refer to Figure 16). The central cell over the state of Indiana

is moving toward the southeast

Convective circulation patterns associated with sea breezes are caused by

land absorbing and radiating heat faster than the water

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 into the wind

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

left and increasing

(Refer to Figure 13). For a flight between San Francisco, CA, and Seattle, WA, you should expect icing to accumulate to 1/4 inch thickness within:

less than 15 minutes

(Refer to Figure 4). The intensity of the turbulence reported at a specific altitude is

light from 5,500 feet to 7,200 feet

(Refer to Figure 13). Analyze the Current Icing and Forecast Icing Products (CIP/FIP) closely along the west coast of the United States. Pilot reports in the region indicate

light icing

Temperature and radiation variations over land with a clear sky typically lead to

minimum temperature occurring after sunrise.

Advection fog is formed as a result of

moist air moving over a colder surface

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

Vertical visibility is shown on Terminal Aerodrome Forecasts (TAF) reports when the sky is

obscured

There is a high pressure system that is located south of your planned route in the Northern Hemisphere on a west to east cross-country flight. To take advantage of favorable winds, you would plan your route

on the north side of the high pressure area.

(Refer to Figure 5). In the TAF from KOKC, the clear sky becomes

overcast at 2,000 feet during the forecast period between 2200Z and 2400Z

A generally recommended practice for autopilot usage during cruise flight in icing conditions is

periodically disengaging the autopilot and hand flying the airplane

Penetrating fog while flying an approach at night, you might experience the illusion of

pitching up

Cumulus clouds often indicate

possible turbulence.

GIVEN: METAR KOUN 151355Z AUTO 22010KT 10SM CLR BLO 120 13/10 A2993 RMK A02 $. The ASOS report indicates that the location is

possibly in need of maintenance

A surface inversion can

produce poor visibility

The ratio of the existing water vapor in the air, as compared to the maximum amount that could exist at a given temperature, is called

relative humidity

What is a characteristic of stable air?

restricted visibility

GIVEN: METAR KPNC 131215 AUTO 33025KT 1/2SM OVC005 00/M03 A2990 RMK A02 SLPNO. This ASOS report indicates that the

sea level pressure is not available

A moist, cold air mass that is being warmed from below is characterized, in part, by

showers and thunderstorms

One of the best visual indications of a thermal is a

smooth cumulus cloud with a concave base.

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

south of a high and to the north of a low

(Refer to Figure 8). In the surface analysis weather chart legend, symbol 12 depicts a

squall line

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

stability of the air being lifted

The conditions most favorable to wave formation over mountainous areas are a layer of

stable air at mountaintop altitude and a wind of at least 15 to 25 knots blowing across the ridge.

(Refer to Figure 8). In the surface analysis weather chart legend, symbol 8 depicts a

stationary frontogenesis

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

Select the true statement concerning thermals

strong thermals have proportionately increased sink in the air between them

The locations of fronts and pressure systems as of chart time are best determined by referring to a

surface analysis chart

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

terrestrial radiation on a clear, relatively still night.

As you approach an airport to land, you observe a convective cloud over the airport with virga below it. This could indicate

the presence of a microburst.

(Refer to Figure 8). In the surface analysis weather chart legend, symbol 9 depicts a

trough or outflow boundary

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

virga

(Refer to Figure 6). What is the maximum sustained wind speed at KOKC in central Oklahoma?

15 kts

(Refer to Figure 5). What is the valid period for the TAF for KMEM?

1800Z to 2400Z

Consider the following statements about mountain waves: 1. Mountain waves always develop in a series on the upwind (windward) side of mountain ridges. 2. In a mountain wave, the air dips sharply downward immediately to the lee side of a ridge, before rising and falling in a wave motion for a considerable distance downstream. 3. If the air is humid and the wave is of large amplitude, lenticular (lens-shaped) clouds mark the wave's crest. 4. In a typical wave, the greatest amplitude is seldom more than 1,000 feet above the ridge crest elevation. From the statements above, select those that are true.

2 and 3

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:

2, 4 and 5

What is the thickness of the cloud layer given a field elevation of 1,500 feet MSL with tops of the overcast at 7,000 feet MSL? METAR KHOB 151250Z 17006KT 4SM OVC010 13/11 A2998

4,500 feet

In reference to clear air turbulence (CAT), areas to be avoided are those where horizontal wind shear exceeds

40 knots per 150 miles

(Refer to Figure 3). The temperature/dewpoint spread at KAUS is

4°C

(Refer to Figure 8). Which symbol is used when there is a change in the front type?

5

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?

5,500 feet AGL

(Refer to Figure 16). According to the convective weather forecast over the state of Indiana, the activity over the northern boundary shows echo tops of

50,000 ft

What is the wind shear forecast in the following TAF? TAF KCVG 231051Z 231212 12012KT 4SM -RA BR OVC008 WS005/27050KT TEMPO 1719 1/2SM -RA FG FM1930 09012KT 1SM -DZ BR VV003 BECMG 20215SM HZ=

500 feet AGL from 270° at 50 KT

(Refer to Figure 4). If the terrain elevation is 1,295 feet MSL, what is the height above ground level of the base of the ceiling?

505 feet AGL

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

59°F and 1013.2 mb

You may anticipate fog when the temperature-dew point spread is

5°F or less and decreasing.

(Refer to Figure 3). What is the reported duration of the rain at the time of the observation at KBRO?

6 minutes

(Refer to Figure 15). What percent coverage of severe thunderstorms is forecast to occur in the area of moderate risk in the north-central United States?

6 to 10

Maximum downdrafts in a microburst encounter may be as strong as

6,000 feet per minute

The height of the bases of the middle clouds in the middle latitudes ranges from

6,500 and 23,000 feet.

(Refer to Figure 9). Which illustration indicates a tropical wave?

7

At approximately what altitude above the surface would you expect the base of cumuliform clouds if the surface air temperature is 33°C and the dewpoint is 15°C?

7,200 feet AGL

(Refer to Figure 4). The base and tops of the overcast layer reported by a pilot are

7,200 feet MSL and 8,900 feet MSL

If the air temperature is +12°C at an elevation of 1,250 feet and a standard (average) temperature lapse rate exists, what will be the approximate freezing level?

7,250 feet MSL

When using a Constant Pressure Analysis Chart for planning a flight at 10,000 feet MSL, a pilot should refer to the

700-millibar analysis

(Refer to Figure 2A). Analyze the regional display of the ceiling and visibility analysis (CVA). On which of the following direct routes can VFR conditions be predominantly expected?

A flight from O to M

(Refer to Figure 2A). Analyze the regional display of the ceiling and visibility analysis (CVA) to determine which areas a flight can expect ceilings consistent with possible terrain obscuration and IFR conditions

A flight over area K

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

Cumuliform clouds

A moist, unstable air mass is characterized by

Cumuliform clouds and showery precipitation.

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

Cumuliform clouds, turbulent air, showery-type precipitation

Which type of cloud is associated with violent turbulence and a tendency toward the production of funnel clouds?

Cumulonimbus mamma

What is the process by which ice can form on a surface directly from water vapor on a cold, clear night?

Deposition

(Refer to Figure 8). In the surface analysis weather chart legend, symbol 10 depicts a

Dryline

If an area on a Convective Outlook Chart is labeled APCHG, this indicates

winds greater than or equal to 35 knots but less than 50 knots

(Refer to Figure 4). The wind and temperature at 12,000 feet MSL as reported by a pilot are

080° at 21 knots and -7° C

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?

1, 3 and 6

Consider the following statements regarding a Pilot Weather Report (PIREP). 1. A vertical visibility entry does not constitute a ceiling. 2. Fog (FG) can be reported only if the visibility is less than 5/8 mile. 3. The ceiling layer will be designated by a "C." 4. Mist (BR) can be reported only if the visibility is greater than or equal to 5/8 statute mile. 5. Temperatures reported below zero will be prefixed with a "-." 6. There is no provision to report partial obscurations. Select the true statements

2, 4 and 6

Consider the following statements regarding an Aviation Routine Weather Report (METAR). 1. A vertical visibility entry does not constitute a ceiling. 2. Fog (FG) can be reported only if the visibility is less than 5/8 mile. 3. The ceiling layer will be designated by a "C." 4. Mist (BR) can be reported only if the visibility is 5/8 mile up to six miles. 5. Temperatures reported below zero will be prefixed with a "-." 6. There is no provision to report partial obscurations. Select the true statements.

2, 4 and 6

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

2-4 minutes

The average lapse rate in the troposphere is

2.0°C per 1,000 feet.

(Refer to Figure 7). Determine the wind and temperature aloft forecast for MKC at 6,000 feet

200° true at 6 knots, temperature +3°C

(Refer to Figure 7). Determine the wind and temperature aloft forecast for DEN at 9,000 feet

230° true at 21 knots, temperature -4°C

(Refer to Figure 7). What wind is forecast for STL at 9,000 feet?

230° true at 32 knots

(Refer to Figure 16). At what speed is the most southern hazard field moving?

25 kts

(Refer to Figure 3). In the report for KBRO, what is the reported ceiling?

25,000 feet

(Refer to Figure 3). What is the reported duration of the rain at the time of the observation at KAUS?

26 minutes

(Refer to Figure 9). Which symbol used on a Surface Analysis Weather Chart represents a dissipating warm front?

3

(Refer to Figure 5). In between 1000Z and 1200Z the visibility at KMEM is forecast to be

3 statute miles

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?

3,700 feet MSL

The distance measured in millibars separating isobars on surface analysis charts is typically

4 MB

On a Surface Analysis Weather Chart, isobars are usually spaced at intervals of

4 millibars

In the following METAR/TAF for HOU, what is the ceiling and visibility forecast on the 7th day of the month at 0600Z? KHOU 061734Z 0618/0718 16014G22KT P6SM VCSH BKN018 BKN035 FM070100 17010KT P6SM BKN015 OVC025 FM070500 17008KT 4SM BR SCT008 OVC012 FM071000 18005KT 3SM BR OVC007 FM071500 23008KT 5SM BR VCSH SCT008 OVC015

4 statute miles visibility and an overcast ceiling at 1,200 feet AGL

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

A low pressure area or trough is an area of rising air

What is indicated by the following report? TYR UUA/OV TYR180015/TM 1757/FL310/TP B737/TB MOD-SEV CAT 350-390

An urgent pilot report for moderate to severe clear air turbulence.

What are the characteristics of an unstable atmosphere?

A warm, humid air mass.

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

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

(Refer to Figure 13). After identifying areas of potential icing, you should review which of the following weather products?

AIRMETs

Which statement is true concerning ASOS/AWOS weather reporting systems?

ASOS locations perform weather observing functions necessary to generate METAR reports

From which measurement of the atmosphere can stability be determined?

Ambient lapse rate

(Refer to Figure 6). What is the cloud coverage at KGSO in North Carolina?

Broken at 10,000 ft. AGL

(Refer to Figure 13A). Review the Graphical Turbulence Guidance (GTG) composite. In which region can you expect to encounter turbulence of greater intensity?

Central United States

(Refer to Figure 8). In the surface analysis weather chart legend, symbol 5 depicts a

Change of front type

From which of the following can the observed temperature, wind, and temperature/dewpoint spread be determined at specified flight levels?

Constant Pressure Charts

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

Continuous updrafts

Which is true regarding the development of convective circulation?

Cool air must sink to force the warm air upward.

Convective SIGMETs are issued for which weather conditions?

Embedded thunderstorms, lines of thunderstorms, and thunderstorms with 3/4-inch hail or tornadoes.

What information would be covered in an AIRMET

Extensive mountain obscurement

When warm air moves over a cold lake, what weather phenomenon is likely to occur on the leeward side of the lake?

Fog

(Refer to Figure 2). After determining your destination is in the vicinity of area J, you should review which of the following weather products next?

METAR

The weather condition normally associated with unstable air is

Good visibility

The best product to provide an overview of forecast weather conditions creating a complete picture of weather affecting regions across the United States is

Graphical Forecasts for Aviation (GFA)

Which statement is true concerning the in-flight hazard of hail?

Hailstones may be thrown outward from a storm cloud for several miles

Radiation fog is most likely to occur under what conditions?

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

One condition necessary for the formation of fog is

High relative humidity

(Refer to Figure 2). After determining your route of flight will take you through area E, you will most likely find which of the following weather conditions?

IFR

Which precipitation type usually indicates freezing rain at higher altitudes?

Ice Pellets

Which is an operational consideration regarding aircraft structural icing?

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.

With respect to advection fog, which statement is true?

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

(Refer to Figure 3). Which station is reporting the wind as calm?

KDAL

(Refer to Figure 3). Which station is reporting the lowest ceiling?

KFTW

(Refer to Figure 13A). For a flight between Denver, CO, and Las Vegas, NV, you should expect the following turbulent conditions:

Moderate or greater

Which situation would most likely result in freezing rain?

Rain falling from air which has a temperature of more than 0°C into air having a temperature of 0°C or less

(Refer to Figure 9). What type of front is shown in illustration 4?

Occluded frontolysis

The general circulation of air associated with a high-pressure area in the Northern Hemisphere is

Outward, downward, and clockwise

When the visibility is greater than 6 SM on a TAF it is expressed as

P6SM

(Refer to Figure 13A). After analyzing your flight path through northwestern Illinois and eastern Iowa, you should continue your flight planning by examining

PIREP

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

Precipitation induced fog

In the following TAF for KMCO, what does "SHRA" stand for? KMCO 021136Z 0212/0312 22005KT P6SM VCSH FEW026 FEW045 SCT180 TEMPO 0212/0214 3SM SHRA BKN020 OVC040 FM021400 27009KT P6SM VCTS SCT020CB BKN035 OVC050 TEMPO 0214/0217 2SM TSRA BKN015CB OVC030 FM021800 34009KT P6SM SCT025 BKN060 FM022100 04010KT P6SM SCT040 BKN080 FM030000 09008KT P6SM SCT040 BKN120

Rain showers

What is the expected duration of an individual microburst?

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

What causes wind?

Pressure differences

Which weather chart depicts the conditions forecast to exist at a specific time in the future?

Prognostic

Which in-flight advisory would contain information on severe icing?

SIGMET

(Refer to Figure 15). Regarding Convective Outlook Charts, when well-organized severe thunderstorms are expected, but in small numbers and/or low coverage, the risk is referred to as

SLGT

Frontal waves normally form on

Slow moving cold fronts or stationary fronts

A moist, warm air mass that is being cooled from below is characterized, in part, by

Smooth air

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.

(Refer to Figure 16). What direction are the hazard fields moving?

Southeast

(Refer to Figure 8). Refer to illustration 12. What does this symbol mean on a Surface Analysis Weather Chart?

Squall line

Tornadoes are most likely to occur with which type of thunderstorms?

Steady-state thunderstorms associated with cold fronts or squall lines

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

Strong updrafts and cumulonimbus clouds

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

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

The intensity trend of a front (as of chart time) is best determined by referring to a

Surface Analysis Chart

The strength and position of a front (as of chart time) is best determined by referring to a

Surface Analysis Chart

Which primary source should be used to obtain forecast weather information at your destination for the planned ETA?

Terminal Aerodrome Forecast (TAF)

Which statement is true regarding a cold front occlusion?

The air ahead of the warm front is warmer than the air behind the overtaking cold front.

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

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

(Refer to Figure 16). What do the blue colored semi-circular polygons located southeast of each cell indicate?

The forecast of where the hazard field will be in 1 hour

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

The sun

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

The temperature spread decreases as the relative humidity increases

What is the base of the ceiling in the following pilot report? KMOB UA /OV APE230010/TM 1515/FL085/TP BE20/SK BKN065/WX FV03SM HZ FU/TA 20/TB LGT

There is a broken layer at 6,500 feet.

What information is contained in a CONVECTIVE SIGMET in the conterminous United States

Tornadoes, embedded thunderstorms, and hail 3/4 inch or greater in diameter

In what part of the atmosphere does most weather occur?

Troposphere

(Refer to Figure 2). After determining your route of flight will take you through area L, you will most likely find which of the following weather conditions?

VFR

To determine the freezing level and areas of probable icing aloft, you should refer to

an AIRMET or SIGMET

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

When there is a low-level temperature inversion with strong winds above the inversion

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

an unstable air mass

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?

Yes, hail can be discharged from the anvil.

Spaces located between the warm or cold pips along a frontal line are an indication of

a frontogenesis

Dashes depicted between the warm or cold pips along a frontal line are an indication of

a frontolysis