050-Meteorology

Dew point is defined as

When does frontal fog, also known as mixing fog, occur ?

What are the meteorological prerequisites, at low level, for thunderstorms formed by lifting processes, over land?

If the QNH at Locarno (200 metres above sea level) is 1025 hPa, what is the approximate QFE ?

A layer in which the temperature decreases with 1°C per 100m is

In the month of August you prepare a flight (cruising level FL 370) from Bombay (19°N – 73°E) to Bangkok (13°N – 100°E). What wind conditions can you expect ?

Low level wind shear is likely to be greatest

What cloud formation is most likely to occur at low levels when a warm air mass overrides a cold air mass ?

The vertical extent of the friction layer depends primarily on

What is the main composition of clouds classified as “high level clouds”” ?

Which of the statements is true concerning squall lines ?

When planning a flight at FL 60, which upper wind and temperature chart would be nearest your flight level ?

Which of the following statements concerning trade winds is correct ?

An observer on the northern hemisphere is under influence of the wind system of a depression, which is moving from West to East. The centre of the depression passes to the South of the observer. For this observer the wind direction is

What surface weather is associated with a stationary high pressure region over land in the winter?

A high pressure area (shallow pressure gradient) covers an area of the Mediterranean Sea and its nearby airport.What surface wind direction is likely at the airport on a sunny afternoon?

An aircraft is flying through the Alps on a warm summer’s day. The weather is fine, and there is a high pressure system in the area. During the flight, a mountain is passed at an altitude of its summit. What reading will the aneroid altimeter give, compared to the summit’s elevation?

Which of the following is true of a land breeze?

Supercooled droplets can occur in

How would you characterise an air temperature of -55°C at the 200 hPa level over western Europe?

Which of the following clouds are classified as medium level clouds in temperate regions ?

The initial phase of a thunderstorm is characterized by

What is a microburst?

Which of the following statements is true regarding moderate-to-severe airframe icing?

In which of these cloud types can icing be virtually ruled out?

Which of the following cloud types can project up into the stratosphere?

The morning following a clear, calm night when the temperature has dropped to the dewpoint, is likely to produce

Which of the following cloud types is found at high levels?

The main factor which contributes to the formation of very low clouds ahead of a warm front is the

You intend to carry out a VFR flight over the Alps, on a hot summer day, when the weather is unstable. What is the best time of day to conduct this flight?

Which statement is true ?

How, if at all, is the relative humidity of an unsaturated airmass influenced by temperature changes?

Which of the following phenomena should be described as precipitation at the time they are observed?

Compare the following TAF and VOLMET reports for Nice:
TAF 240716 VRB02KT CAVOK = 0920Z 13012KT 8000 SCT040CB BKN100 20/18 Q1015 TEMPO TS =
What can be concluded from the differences between the two reports ?

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

During periods of prolonged clear skies associated with anticyclonic conditions, the

In which of the following situations can freezing rain be encountered ?

Areas of sinking air are generally cloudless because as air sinks it

Why do tropical revolving storms tend to develop mostly in the western parts of the tropical oceans?

What does the term TREND signify?

What is the relationship, if any, between QFE and QNH at an airport situated 50 FT below sea level?

An aircraft is flying over the sea at FL 90; the true altitude is 9100 feet; local QNH is unknown. What assumption, if any, can be made about the air mass in which the aircraft is flying ?

If atmospheric conditions exist such that the temperature deviation is ISA +10°C in the lower troposphere up to 18000 FT, what is the actual layer thickness between FL 60 and FL 120 ?

An aircraft is flying at FL 80. The local QNH is 1000 hPa. After the second altimeter has been adjusted to the local QNH, the reading will be approximately

A strong, dry and warm katabatic wind, produced by prior enforced ascent of air over hills or mountains is known as a

During July flights from Bangkok (13°N – 100°E) to Karachi (25°N – 67°E) experience an average tailwind component of 22 kt. In January the same flights, also operating at FL 370, have an average headwind of 50 kt. What is the reason for this difference?

Which of the following types of clouds are evidence of unstable air conditions?

What are the requirements for the formation of a thunderstorm?

Which of the following is true concerning atmospheric pressure ?

What units are used to report vertical wind shear?

What is a trend forecast?

What type of air movement is associated with the centre line of a trough?

Which of the following conditions is most likely to cause airframe icing ?

Above and below a low level inversion the wind is likely to

Which one of the following local winds is a Foehn wind?

When the subscale is set to the QNH of an airfield the pressure altimeter indicates

Under what condition does pressure altitude have the same value as density altitude ?

On a clear summer day, turbulence caused by solar heating is most pronounced

The difference between geostrophic wind and gradient wind is caused by

Steady precipitation, in contrast to showery precipitation falls from

Which of the following weather reports is a warning of conditions that could be potentially hazardous to aircraft in flight ?

Which of the following best describes the intertropical convergence zone ?

What types of cloud will you meet flying towards a warm front ?

A microburst

What name is given to the low level wind system between the subtropical high pressure belt and the equatorial trough of low pressure (ITCZ) ?

On a particular day part of a polar front jet stream runs from north to south in the northern hemisphere. This means that

Which of the following weather conditions favour the formation of radiation fog?

A parcel of unsaturated air is lifted to just below the condensation level and then returned to its original level. What is the final temperature of the parcel of air?

Advection is :

When is the RVR reported at most airports?

The sea breeze is a wind from the sea

What is the name of the hot, local wind, that blows downwards from mountain chains? In the Alps, for instance, it may exist both as a southerly or northerly wind depending on the weather situation

What wind conditions, occuring just before dawn, favour the formation of fog at an airport where the temperature is 15°C and the dew point is 14°C?

Which is true of a typical non frontal thermal depression?

With which of the following types of cloud is “+RA” precipitation most commonly associated?

When in the upper part of a layer warm air is advected the

The lowest assumed temperature in the International Standard Atmosphere (ISA) is :

With what type of cloud is “DZ” precipitation most commonly associated?

The jetstream and associated clear air turbulence can sometimes be visually identified in flight by

Which of the following conditions is most likely to lead to the formation of advection fog ?

Considering the North Atlantic region between 30°N and 65°N and the adjacent land areas during mid-summer, the predominant pressure systems are

Which of the following causes echoes on meteorological radar screens?

Which of the following phenomena should be described as precipitation at the time they are observed?

In temperate latitudes what weather conditions may be expected over land during the summer in the centre of a stationary high pressure zone ?

Which of the following weather reports could be, in accordance with the regulations, abbreviated to “CAVOK””?

What is the minimum speed for a wind to be classified as a jet stream?

Around Paris on January 3rd at 1800 UTC, the surface temperature, under shelter, is 3°C. The sky is covered by 8 oktas of stratus. QNH is 1033 hPa. If the sky is covered all night, the minimum temperature of the night of January 3rd to January 4th should be

Which of the following statements is true concerning advection fog ?

Which of the following conditions gives the highest value of the QNH ?

Why are indications about the height of the tropopause not essential for flight documentation in the tropics?

The process by which water vapour is transformed directly into ice is known as

How do air masses move at a warm front ?

At FL 180, the air temperature is -35°C.The air density at this level is:

In Zurich during a summer day the following weather observations were taken:
160450Z 23015KT 3000 +RA SCT008 SCT020 OVC030 13/12 Q1010 NOSIG =
160650Z 25008KT 6000 SCT040 BKN090 18/14 Q1010 RERA NOSIG =
160850Z 25006KT 8000 SCT040 SCT100 19/15 Q1009 NOSIG =
161050Z 24008KT 9999 SCT040 SCT100 21/15 Q1008 NOSIG =
161250Z 23012KT CAVOK 23/16 Q1005 NOSIG =
161450Z 23016KT 9999 SCT040 BKN090 24/17 Q1003 BECMG 25020G40KT TS =
161650Z 24018G35KT 3000 +TSRA SCT006 BKN015CB 18/16 Q1002 NOSIG =
161850Z 28012KT 9999 SCT030 SCT100 13/11 Q1005 NOSIG =
What do you conclude based on these observations?

What degree of turbulence, if any, is likely to be encountered while flying through a cold front in the summer over Central Europe at FL 100?

At what time of day, or night, is radiation fog most likely to occur?

During the late afternoon an air temperature of +12°C and a dew point of +5°C were measured. What temperature change must occur during the night in order to induce saturation?

In which zone of a jet stream is the strongest CAT to be expected ?

A squall line usually is most likely to be encountered

At what degree of icing can ICAO’s “No change of course and altitude necessary” recommendation be followed ?

Under which of these conditions is radiation fog most likely to form?

Which one of the following statements applies to the tropopause ?

Assume that an aircraft is flying in the northern hemisphere at the 500 hPa pressure surface on a heading of 270 degrees. Which of the following statements is correct?

If the QNH at Locarno (200 metres above sea level) is 1015 hPa, what is the approximate QFE?
(Assume 1hPa = 8m)

During a flight at FL 100 from Marseille (QNH 1012 hPa) to Palma de Mallorca (QNH 1015 hPa), an aircraft remains at a constant true altitude. The reason for this is that :

Which of the following statements describes a microburst?

While crossing a jet stream at right angles in Western Europe (3000 FT below its core) and OAT is decreasing, what would be the prevailing wind?

Runway Visual Range (RVR) is

An aircraft is flying from south to north, above the polar front jet stream, at FL 400 in the southern hemisphere. What change, if any, in temperature will be experienced ?

During a flight over the sea at FL 100 from Marseille (QNH 1016 hPa) to Palma de Mallorca (QNH 1016 hPa), the true altitude is constantly decreasing. What is the probable reason for this ?

If the QFE at Locarno (200 metres above sea level) is 1000 hPa, what is the approximate QNH?

The most hazardous type of cloud that may be encountered on a cross country flight is

In addition to a lifting action, what are two other conditions necessary for thunderstorm formation ?

What type of cloud can produce hail showers?

Which of the following conditions is most likely to lead to the formation of steam fog (arctic smoke)?

What information is required to convert a minimum safe altitude into a lowest usable flight level?

During which months is the Hurricane season in the Caribbean?

The barometric compensator of an altimeter is locked on reference 1013.2 hPa. The aircraft has to land on a point with an elevation of 290 feet where the QNH is 1023 hPa. Assuming that 1 hPa corresponds to 27 FT, the reading on the altimeter on the ground will be:

What characteristics will the surface winds have in an area where the isobars on the weather map are very close together ?

The relative humidity of a sample air mass is 50%. How is the relative humidity of this air mass influenced by changes of the amount of water vapour in it ?

Where, during a flight from Marseille to Dakar, in July, may the ITCZ be encountered ?

In what hPa range is an upper weather chart for FL 340 situated ?

What is the average height of the arctic jet stream core ?

What, approximately, is the average height of the tropopause over the equator ?

Steaming fog (arctic sea smoke) occurs in air :

What is normally the most effective measure to reduce or avoid CAT effects?

When isobars, for an area in the mid-latitudes on a weather map, are close together, the wind is most likely to be

Which of the following statements is an interpretation of the SIGMET ?
SIGMET VALID 121420/121820 embd ts obs and fcst in w part of athinai fir / mov e / intst nc =

What characteristics will the surface winds have in an area where the isobars on the weather map are very close together ?

What is the relationship between meteorological visibility (met.vis.) and RVR in homogeneous fog?

Refer to the following TAF for Zurich.
LSZH 261019 20018G30KT 9999 -RA SCT050 BKN080 TEMPO 23012KT 6000 -DZ BKN015 BKN030 BECMG 1518 23020G35KT 4000 RA OVC010=
The lowest visibility forecast at ETA Zurich 1430 UTC is:

The transition from SW to NE monsoon in India occurs in

Refer to TAF below.
EGBB 261812 28015G25KT 9999 SCT025 TEMPO 1822 29018G35KT 5000 SHRASN BKN010CB PROB30 TEMPO 1821 1500 TSGR BKN008CB BECMG 2124 26010KT
From the TAF above you can assume that visibility at 2055Z in Birmingham (EGBB) will be :

In which weather report would you expect to find information about icing conditions on the runway?

A cumulonimbus cloud at moderate latitudes in summer contains

Below a low level inversion visibility is often

Which wind systems converge on the ITCZ, when it lies at the equator?

Geostrophic wind is the wind when isobars are

What is the main energy source of a tropical revolving storm?

Which statement is true for hurricanes in the North Atlantic ?

The isobars drawn on a surface weather chart represent lines of equal pressure

What weather is prevalent in the zone of easterly waves?

Which of the following conditions would cause the altimeter to indicate a lower altitude than that actually flown ?

In which of these cloud types can icing be virtually ruled out ?

In which of the following circumstances is a SIGMET issued ?

During the climb after takeoff, the altimeter setting is adjusted at the transition altitude. If the local QNH is 966 hPa, what will happen to the altimeter reading during the resetting procedure?

Hoar frost forms on an aircraft as a result of

What values are used for the forecasted wind at higher levels?

If Paris reports a wind of 30012KT on the METAR, what wind velocity would you expect to encounter at a height of 2000 feet above the ground ?

In the northern hemisphere with an anticyclonic pressure system the geostrophic wind at 2000 FT over the sea is 060/15. At the same position the surface wind is most likely to be

In a layer of air the decrease in temperature per 100 metres increase in height is more than 1°C. This layer can be described as being

In Central Europe when is the greatest likelihood for thunderstorms due to warm updrafts ?

Refer to the TAF for Amsterdam airport.nFCNL31 281500nEHAM 281601 14010KT 6000 -RA SCT025 BECMG 1618 12015G25KT SCT008 BKN013 TEMPO 1823 3000 RA BKN005 OVC010 BECMG 2301 25020KT 8000 NSW BKN020 =nFlight from Bordeaux to Amsterdam, ETA 2100 UTC. What is the minimum visibility forecast for ETA Amsterdam ?

An easterly wave is a :

When otherwise calm and clear conditions exist a station on the shore of a large body of water will experience wind

The stability in a layer is increasing if :

The most likely reason for radiation fog to dissipate or become low stratus is :

Which of the following statements is an interpretation of the SIGMET ?nLSAW SWITZERLAND 0307 SIGMET 2 VALID 030700/031100 LSSW mod to sev cat fcst north of alps btnfl260andfl380/stnr/intsf=

If you are planning a flight at FL 170, which of these upper wind and temperature charts would be nearest your flight level ?

Which of the following is typical for the passage of a cold front in the summer ?

Where, as a general rule, is the core of the polar front jet stream to be found?

Refer to the following TAF extract:
BECMG 1821 2000 BKN004 PROB30 BECMG 2124 0500 FG VV001
What visibility is forecast for 2400 UTC?

The polar front is the boundary between :

How does the height of the tropopause normally vary with latitude in the northern hemisphere ?

A sample of moist but unsaturated air may become saturated by

Which jet stream blows all year round, over the northern hemisphere ?

Refer to the following TAF for Zurich
LSZH 061019 20018G30KT 9999 -RA SCT050 BKN080 nTEMPO 23012KT 6000 -DZ BKN015 BKN030 BECMG 1518 23020G35KT 4000 RA OVC010= nThe lowest cloud base forecast at ETA Zurich (1200 nUTC) is:

Which forces are balanced with geostrophic winds?

Which of the following changes of state is known as sublimation ?

During the formation of rime ice in flight, water droplets freeze

An inversion is a layer of air in which the temperature

Fair weather cumulus often is an indication of

The tropopause is lower

The temperature at FL 110 is -5°C. What will the temperature be at FL 50 if the ICAO standard lapse rate is applied ?

Refer to the following TAF extract;
BECMG 1821 2000 BKN004 PROB30 BECMG 2124 0500 FG VV001
What does the abbreviation “PROB30″” mean?

The pressure altitude is equal to the true altitude if

In which of the following METAR reports, is the probability of fog formation in the coming night the highest ?

Tropical revolving storms do not occur in the southeast Pacific and the south Atlantic because

The QNH is equal to the QFE if

Considering the North Atlantic region between 30°N and 65°N together with the adjacent land areas during winter, the normal disposition of the main anticyclones at the surface is

Vertical wind shear is