Vayudoot Aviation

1. In a polar front depression, an occlusion is called a warm occlusion when the cold air

behind is colder than the cold air in front, with the warm air being at a high altitude.

in front of the surface position of front is only at a high altitude

behind is colder than the cold air in front.

behind is less cold than the cold air in front, with the warm air at a high altitude.

2. In which of the following regions does polar maritime air originate?

Region of British Isles

Baltic Sea

Black Sea

East of Greenland

3. On an aerodrome, when a warm front is approaching

QFE increases and QNH decreases.

QFE and QNH increase.

QFE and QNH decrease.

QFE decreases and QNH increases.

4. What will be the effect on the reading of an altimeter of an aircraft parked on the ground as an active cold front is passing?

It will fluctuate up and down by about +/- 50 feet.

It will remain unchanged.

It will first decrease then increase.

It will first increase then decrease.

5. In which approximate direction does the centre of a frontal depression move?

In the direction of the sharpest pressure increase.

In the direction of the isobars ahead of the warm front.

In the direction of the isobars behind the cold front.

In the direction of the warm sector isobars.

6. What characterizes a stationary front?

The surface wind usually has its direction parallel to the front

The warm air moves at approximately half the speed of the cold air

The surface wind usually has its direction perpendicular to the front

The weather conditions that it originates is a combination between those of an intense cold front and those of a warm and very active front

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

saturation of the warm air by rain falling into it and evaporating

warm air moving over a cold surface

reduction of outgoing radiation due to clouds

saturation of the cold air by rain falling into it and evaporating

8. What will be the effect on the reading of an altimeter of an aircraft parked on the ground during the period following the passage of an active cold front?

It will show a small increase or decrease.

It will remain unchanged.

It will have increased.

It will have decreased.

9. Read this description: “After such a fine day, the ring around the moon was a bad sign yesterday evening for the weather today. And, sure enough, it is pouring down outside. The clouds are making an oppressively low ceiling of uniform grey; but at least it has become a little bit warmer.” Which of these weather phenomena is being described?

Weather at the back of a the cold front

A blizzard

A warm front

A cold front

10. What is the relative movement of the two air masses along a cold front?

Cold air slides over a warm air mass

Warm air pushes under a cold air mass

Cold air pushes under a warm air mass

Warm air pushes over a cold air mass

11. At the approach of a warm front (northern hemisphere) the wind direction changes from the surface up to the tropopause. The effect of this change is that the wind

backs in the friction layer and and backs above the friction layer

veers in the friction layer and backs above the friction layer

backs in the friction layer and veers above the friction layer

veers in the friction layer and veers above the friction layer

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

At some 500 km AS, later CS and at some 80 km before the front CB

At some 800 km CS, later AS, and at some 300 km NS until the front

Extensive areas of fog. At some 100 km from the front NS begin

At some 500 km from the front, groups of CB, later at some 250 km thickening AS

13. When do cold occlusions occur most frequently in Europe?

Summer

Winter

Winter and spring

Autumn and winter

14. Where is the coldest air to be found, in an occlusion with cold front characteristics?

Behind the front.

At the junction of the occlusion.

Ahead of the front.

At the surface position of the front.

15. The polar front is the boundary between

maritime polar air and continental polar air.

arctic air and tropical air.

arctic air and polar air.

polar air and tropical air.

16. How are the air masses distributed in a cold occlusion ?

The coldest air behind and the warm air in front of the occlusion; the less cold air mass is above ground level

The coldest air mass behind and the less cold air in front of the occlusion; the warm air mass is above ground level

The coldest air in front of and the warm air behind the occlusion; the less cold air is above ground level

The coldest air in front of and the less cold air is behind the occlusion; the warm air mass is above ground level

17. What type of precipitation would you expect at an active unstable cold front?

Light to moderate continuous rain

Showers associated with thunderstorms

Drizzle

Freezing rain

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

Altostratus.

Cumulus.

Nimbostratus.

Cumulonimbus.

19. What are the typical differences between the temperature and humidity between an air mass with its origin in the Azores and an air mass with its origin over northern Russia?

The North-Russian air is warmer and dryer than the air of the Azores.

The air of the Azores is warmer and dryer than the North- Russian air.

The air of the Azores is warmer and more humid than the North-Russian air

The North-Russian air is colder and more humid than the air of the Azores.

20. Which of the following statements concerning the core of a polar front jet stream is correct?

It lies in the warm air; its pressure surfaces are horizontal at the height of the core

It lies at a height where there is no horizontal temperature gradient; the slope of the pressure surfaces at the height of the core is at its maximum

It and its surface projection lie in the warm air

It lies in the cold air; the thermal wind reverses direction at the height of the core

21. What cloud cover is typical for a wide warm sector of a polar front depression over Central Europe in the summer ?

Sky clear

BKN CU and CB

Fair weather CU

ST with drizzle

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

Rapid increase in temperature once the front has passed

Mainly layered clouds

Rapid drop in pressure once the front has passed

Mainly towering clouds

23. Which of the following describes a warm occlusion?

The coldest air mass is ahead of the original warm front

The warmer air mass is ahead of the original warm front

The air mass ahead of the front is drier than the air mass behind the front

The air mass behind the front is more unstable than the air mass ahead of the front

24. Where does polar continental air originate?

Siberian landmass.

The region of the Baltic sea.

The region of Greenland

Areas of arctic water.

25. How do you recognize a cold air pool?

A cold air pool may only be recognized on the surface chart as a low pressure area.

As a high pressure area aloft (e.g. on the 500 hPa chart).

As a low pressure area aloft (e.g. on the 500 hPa chart).

A cold air pool may only be recognized on the surface chart as a high pressure area.

26. What type of front / occlusion usually moves the fastest?

Cold occlusion

Warm front.

Warm occlusion.

Cold front.

27. A squall line usually is most likely to be encountered

at an occluded front

behind of a stationary front

in an air mass with cold mass properties

ahead of a cold front

28. In which air mass are extremely low temperatures encountered?

Tropical continental air

Arctic maritime air.

Polar maritime air.

Polar continental air.

29. Which of the following zones is most likely to encounter little or no precipitation?

Frontal zones.

The north side of the alps with a prevailing Foehn from the south.

Occlusions.

The north side of the alps with a prevailing Foehn from the north.

30. Thunderstorms in exceptional circumstances can occur in a warm front if

the warm air is convectively stable.

the cold air is convectively stable.

the cold air is convectively unstable.

the warm air is convectively unstable.

31. Thunderstorms can occur on a warm front if the

warm air is moist and the environmental lapse rate is less than the saturated adiabatic lapse rate

warm air is moist and the environmental lapse rate exceeds the saturated adiabatic lapse rate

cold air is moist and the environmental lapse rate is less than the dry adiabatic lapse rate

cold air is moist and the environmental lapse rate exceeds the saturated adiabatic lapse rate

32. What is the surface visibility most likely to be, in a warm sector of tropical maritime air, during the summer?

Good (greater than 10 km).

Very poor (less than 1 km).

Very good (greater than 50 km).

Moderate (several km).

33. 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 decrease in headwind

A veering in the wind direction

A backing in the wind direction

An increase in tailwind

34. Frontal depressions can be assumed to move in the direction of the 2000 feet wind

in the warm sector

behind the cold front

at the apex of the wave

in front of the warm front

35. Which of the following conditions are you most likely to encounter when approaching an active warm front at medium to low level ?

Extreme turbulence and severe lightning striking the ground.

High cloud base, good surface visibility, and isolated thunderstorms.

Severe thunderstorms at low altitude.

Low cloud base and poor visibility.

36. The approximate inclined plane of a warm front is

1/50

1/300

1/500

1/150

37. What will be the effect on the reading of an altimeter of an aircraft parked on the ground shortly before an active cold front passes?

It will fluctuate up and down by about +/- 50 feet.

It will be decreasing.

It will be increasing.

It will remain unchanged.

38. What is encountered during the summer, over land, in the centre of a cold air pool?

Nothing (CAVOK).

Showers and thunderstorms.

Strong westerly winds.

Fine weather CU.

39. How do air masses move at a warm front?

Cold air overrides a warm air mass

Warm air overrides a cold air mass

Cold air undercuts a warm air mass

Warm air undercuts a cold air mass

40. During a cross-country flight at FL 50, you observe the following sequence of clouds: Nimbostratus, Altostratus, Cirrostratus, Cirrus. Which of the following are you most likely to encounter?

Decreasing temperatures.

Strong, gusty winds.

Increasing temperatures.

A strong downdraught.

41. In which main direction does a polar front depression move?

Along the front towards the west

Across the front towards the south

Across the front towards the north

Along the front towards the east

42. A frontal depression passes through the airport. What form of precipitation do you expect?

Continous rain or snow while the frontal wave passes for a period of some 24 hours.

Rain or snow during about 12 hours until the warm front arrives. Within the warm sector the rain increases. Improvement on the passage of the cold front

Continuous rain or snow during 6 hours until the warm front arrives. The precipitation stops for several hours within the warm sector. On the arrival of the cold front, showers within a couple of hours

Showers during some 2 hours until the warm front arrives. Drizzle in the warm sector within 12 hours. Rain or snow on the passage of the cold front.

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