Meteorology - Level 2
Which of the following conditions is most likely to cause airframe icing?
+FZRA
Which of the following phenomena can produce a risk of aquaplaning?
+RA
What is the final temperature of unsaturated surface air at 12° C, which rises to 6.000 ft?
-06° C
You would expect mixed clear and rime icing in the temperature range... and no icing below...
-3º C to -25º C; -45º C
If the wind is from the East, the wind direction is reported as:
090°
If the QFE at Locarno (200 metres above sea level) is 980 hPa, what is the approximate QNH?
1005 hPa.
QFE 1000 hPa at an altitude of 200 m AMSL. What will the approximate QNH be?
1025 hPa.
You are departing an aerodrome (600 ft AMSL, QNH 1012 hPa) and proceed to another airfield (195 ft AMSL) with the same QNH. After landing, which barometric setting on the altimeter makes it again indicate 600 ft?
1027
When a CC layer lies over a West European plane in summer, with a mean terrain height of 500 m above sea level, the average cloud base could be expected:
15 000 - 25 000 ft above ground level.
You plan a flight over a mountain range at a true altitude of 15000 FT/AMSL. The air is on an average 15° C colder than ISA, the pressure at sea level is 1003 hPa. What indication must the altimeter (setting 1013.2 hPa) read?
16230 FT.
In which of the following METAR reports, is the probability of fog formation in the coming night the highest?
1850Z 15003KT 6000 SCT120 05/04 Q1032 BECMG 1600 =
The ITCZ in July is?
20 deg N over west Africa.
If the wind at altitude is 240/35 KT, the most likely wind on the surface at an inland airfield is:
220/20 KT.
What is a SPECI?
A report produced when significant changes have occurred.
After passing at right angles through a very active cold front in the direction of the cold air, what will you encounter, in the northern hemisphere immediately after a marked change in temperature?
A veering in the wind direction.
What is the easterly wave?
A wave in the trade wind belt, moving from east to west, with severe convective activity in the rear of its trough.
The airborne system for reporting weather data automatically to the WAFCs is called:
ASDAR.
Two aircraft, one with a sharp wing profile (S), and the other with a thick profile (T), are flying through the same cloud with same true airspeed. The cloud consists of small supercooled droplets. Which of the following statements is most correct concerning ice accretion?
Aircraft S experiences more icing than T.
SIGMETs are issued as a warning of weather conditions hazardous to which aircraft?
All aircraft.
Under which conditions would you expect the heaviest clear ice accretion to occur in a CB?
Between -2° C and -15° C.
A high pressure (or anticyclone) is characterized by:
Both b) and c) are correct.
With what type of cloud is +TSRA precipitation most commonly associated?
CB
Which of the following types of clouds are evidence of unstable air conditions?
CU, CB.
For international aviation meteorological purposes, temperature is measured in degrees:
Celsius.
Several physical processes contribute to atmospheric warming. Which of the following contribute the most?
Convection and condensation.
Which of the following phenomena should be described as precipitation at the time they are observed?
DZ
During the life cycle of a thunderstorm, which stage is characterized predominately by downdrafts?
Dissipating.
What can be said about the formation of Haze?
Dust particles are trapped below an inversion.
In an air mass, if the ... is higher than the ... and lower than the ... the air mass is conditionally unstable.
ELR, SALR, DALR
Which of the following combinations contain the greatest air density?
High pressure and low temperature.
You fly from east to west at the 500 hPa level in the Northern hemisphere:
If the wind is from the North, there is a gain in altitude.
In which of the following conditions is moderate to severe airframe icing most likely to be encountered?
In Nimbostratus cloud.
Most strong air currents at higher levels (jet streams) have a westerly direction. There is, however, an important easterly jet stream. When and where is it likely to be encountered?
In summer from south-east Asia extending over southern India to central Africa.
Intensity of precipitation is described as:
Intermittent, moderate or heavy.
Lines connecting points of equal pressure are called:
Isobars.
What is the geostrophic wind?
It blows parallel to straight isobars, when no friction is present.
What happens to the temperature of a saturated air mass when forced to descend?
It heats up less than dry because of evaporation.
You observe the altimeter in a parked aircraft shortly before an active cold front passes. What does the altimeter indicate?
It increases.
Which of the following statements is true regarding moderate to severe airframe icing?
It is likely to occur in nimbostratus cloud.
Which type wind flows down slope becoming warmer and dryer?
Katabatic wind.
When are cyclones most likely? (Northern Hemisphere)
Late Summer.
In a polar front jet stream in the Northern Hemisphere, where is there likely to be the greatest probability of turbulence?
Looking downstream, to the left.
A body of air over the ocean is referred to as:
Maritime air.
Which air masses do most often contribute to the weather situation in Western Europe?
Maritime tropical air, maritime polar air.
What hazard is likely to be encountered by a jet aircraft flying at 29.000ft, prior to overtaking the surface position of a cold front?
Moderate to severe turbulence.
Which of the following types of cloud is most likely to be associated with prolonged and continuous moderate rain?
NS
What cloud type is prone to +RA?
NS.
Which type frontal system is normally crossed by the jetstream?
Occluded front.
Where do you get freezing rain?
Rain falling from an inversion into an area below 0 C.
Which types of clouds are typical evidence of stable air conditions?
ST, AS
Which of the following weather factors will not cause the formation of thunderstorms?
Sea fog.
Fog which reaches only 2 metres above ground or 10 metres above the sea is called:
Shallow fog.
Where are TRS not likely to form?
South Atlantic.
Which conditions lead to mountain waves?
Stable air, speed , > 20 kts across the ridge.
Steady precipitation, in contrast to showers, preceding a front is an indication of:
Stratiform clouds with little or no turbulence.
Which of the following statements concerning the conditions in the lower part of the atmosphere is correct?
The tropopause is lower during the winter than in summer.
What relationship exists between the wind at 3.000 feet and the surface wind?
The wind at 3.000 feet is parallel to the isohypses and the surface wind direction is across the isobars toward the low pressure and the surface wind is weaker.
What are trade winds?
The wind zones towards the Intertropical Convergence Zone.
What information is contained in a CONVECTIVE SIGMET?
Tornadoes, embedded thunderstorms, and hail 3/4 inch or greater in diameter.
A V-shaped extension of a low pressure area is called a:
Trough.
How would you find the velocity of the warm front?
Two thirds of the speed found by measuring the distance between the isobars along the front itself.
Which of the following METARs, written at 1850UTC, will most likely give fog formation over the coming night?
VRB002 8000 FEW100 12/09 Q1025 BECMG 0800
Define the Foehn:
Warm and dry air descending at the leeward side of the Alps.
State in which type of front supercooled raindrops most frequently occur?
Warm front.
Under what conditions is RVR measured?
When the meteorological visibility is lower than 1500 metres.
At what time of the year, are the paths of north Atlantic lows moving from west to east generally, at their most southerly position?
Winter.
x8/8 stratus base 200 FT/AGL is observed at sunrise at an aerodrome in the north of France; the QNH is 1028 hPa and there is a variable wind of 3 kt. What change in these clouds is likely at 12:00 UTC in summer and winter?
Winter: OVC base 500 FT/AGL; summer SCT base 3.000 FT/AGL.
A wind sounding in the region of a polar front jet stream gives the following wind profile (Northern hemisphere). 900hPa 220/20kt 800hPa 220/25kt 700hPa 230/35kt 500hPa 260/60kt 400hPa 280/85kt 300hPa 300/100kt 250hPa 310/120kt 200hPa 310/80kt Which system is the jet stream associated with:
With a warm front.
If one kilo of a substance has a higher specific heat than one kilo of another substance, then after the same time exposure to direct sunlight the first substance will be at:
a lower temperature.
With the passage of a cold front crossing the United Kingdom from the North Atlantic, the following weather changes can be expected:
a veer in the wind, pressure falling then starting to rise.
In a low pressure:
a) , b) and c) are all correct.
A pressure difference of 10 hPa close to the ground corresponds to a height difference of:
about 300 ft.
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:
absolutely unstable.
Which of the following is untrue regarding the importance of the tropopause:
air temperature starts to fall severely above the tropopause.
Sea fog:
all of the above.
In the Northern hemisphere, surface friction causes the geostrophic wind to:
back and decrease.
The gradient wind:
blows parallel to curved isobars due to a combination of the pressure gradient force, geostrophic force, and cyclostrophic force.
The dewpoint temperature:
can be equal to the air temperature.
A thunderstorm has the following stages in its life cycle:
cumulus of building, mature and dissipating.
Horizontal differences in the mean temperature of a layer are caused by:
deferential heating of the earths surface.
The geostrophic wind depends on:
density, earths rotation, geographic latitude.
The gradient wind blows parallel to curved isobars:
due to a combination of pressure gradient force, geostrophic force and cyclostrophic force.
In TAF and METAR decodes, DU, DZ and DS mean respectively:
dust, drizzle, dust storms.
Name the conditions for the formation of radiation fog:
flat landscape, a clear night, no wind conditions.
In a low pressure system the convergence at the surface is caused by:
frictional forces.
Under anticyclone conditions in the northern hemisphere, with curved isobars the speed of the gradient wind is:
greater than the geostrophic wind.
Contours on a weather chart indicate:
heights of pressure levels AMSL.
A SIGMET...
is a warning of meteorological hazards in the FIR for all aircraft.
A warm air mass:
is cooled from below by the base layer.
Rising air cools because:
it expands.
Minimum land surface temperatures normally occur... and the diurnal variation of surface temperature is... in overcast conditions.
just after sunrise, less
A certain amount of water vapor saturated air (i.e. intestinal gases) is transported from sea-level up to 34.000 ft. In the same amount of dry air, the volume of this gas is:
larger.
The thickness of the troposphere varies with:
latitude.
When in the upper part of a layer warm air is advected the:
stability increases in the layer.
The formation of high and low pressure areas is normally caused by:
temperature differences.
Which of the following statements is true:
the dew point of a sample of air varies with the temperature of the sample.
If a strongly wind perpendicular to a ridge decreases or reverses in direction at medium and high levels the likely result is:
travelling rotors with very severe turbulence.
The percentage concentration of gases in the atmosphere is constant from the surface of the earth to a certain altitude with the exception of:
water vapour.
The Intertropical convergence zone (ITCZ) particularly affects:
western Africa between 10° and 20° N and the northern coasts of the Arabian sea in July.
The ITCZ is best described as:
where the trade winds of the north and southern hemisphere meet.
