Vayudoot Aviation

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

Around midnight

Early morning.

Late morning.

Mid - afternoon

2. In which stage of the life cycle of a single thunderstorm cell occur both up- and downdrafts simultaneously?

In all stages

Mature stage

Cumulus stage

Dissipating stage

3. How long does a typical microburst last?

1 to 5 minutes.

1 to 2 hours.

Less than 1 minute.

About 30 minutes.

4. What weather condition would you expect at a squall line?

Fog

Strong steady rain

Strong whirlwinds reaching up to higher levels

Thunderstorms

5. What are the requirements for the formation of a thunderstorm?

A cumulus cloud with sufficient moisture associated with an inversion

A stratocumulus cloud with sufficient moisture

Water vapour and high pressure

An adequate supply of moisture, conditional instability and a lifting action

6. During which stage of thunderstorm development are rotor winds characterized by roll clouds most likely to occur?

Dissipating stage.

Mature stage.

Cumulus stage and mature stage.

Cumulus stage.

7. What is a microburst?

A concentrated downdraft with high speeds and a higher temperature than the surrounding air.

A small low pressure system where the wind circulates with very high speeds.

An extremely strong wind gust in a tropical revolving storm.

A concentrated downdraft with high speeds and a lower temperature than the surrounding air.

8. Aircraft struck by lightning may sometimes get considerable damage and at least temporarily the manoeuvring of the aircraft will be made more difficult. Which one of the following statements is correct?

Aircraft made by composite material may get severe damage, the crew may be blinded and temporarily lose the hearing

An aircraft made by metal has a certain capacity to attract a lightning, but the lightning will follow the surface and therefore no damage will be caused.

An aircraft has in the atmosphere the same qualities as a “Faradays cage”, which means that struck of lightning seldom occurs. But if it happens, the result will be an occasional engine failure. The crew may get a shock.

Aircraft made by composite material can’t conduct a lightning and will therefore very seldom be struck

9. Which thunderstorms move forward the fastest?

Thermal thunderstorms.

Frontal thunderstorms.

Thunderstorms formed by lifting processes.

Orographic thunderstorms.

10. During the life cycle of a thunderstorm, which stage is characterized predominantly by downdrafts?

Anvil stage

Cumulus stage

Mature stage

Dissipating stage

11. The diameter and the life time of a typical microburst are in the order of

8 km and 5-15 minutes

4 km and 30-40 minutes

12 km and 5-10 minutes

4 km and 1-5 minutes

12. The initial phase of a thunderstorm is characterized by

continuous up draughts

frequent lightning

continuous downdraughts

rain starting at surface

13. A gust front is

normally encountered directly below a thunderstorm

formed by the cold air outflow from a thunderstorm

another name for a cold front

characterized by heavy lightning

14. Isolated thunderstorms of a local nature are generally caused by

frontal lifting (warm front).

thermal triggering.

frontal occlusion.

frontal lifting (cold front).

15. Which of the following statements describes a microburst ?

A small low pressure system where the wind circulates at high speed

A high speed downdraft of air with a higher temperature than its surroundings

An extremely strong wind gust associated with a tropical revolving storm

A high speed downburst of air with a generally lower temperature than its surroundings

16. Continuous up draughts occur in a thunderstorm during the

cumulus stage.

mature stage.

dissipating stage

period in which precipitation is falling.

17. Which thunderstorms generally develop in the afternoon in summer over land in moderate latitudes?

Cold mass thunderstorms

Warm front thunderstorms

Occlusion thunderstorms

Airmass thunderstorms

18. In which of the following areas is the highest frequency of thunderstorms encountered?

Temperate

Subtropical

Tropical

Polar

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

Unstable conditions and low atmospheric pressure

Stable conditions and high moisture content

Unstable conditions and high moisture content

Stable conditions and low atmospheric pressure

20. Where is a squall line to be expected?

Behind a cold front.

In front of an active cold front.

In front of a cold front occlusion at higher levels.

At the surface position of a warm front.

21. What is the approximate maximum diameter of a microburst?

20 km

4 km

50 km

400 m

22. A microburst

occurs only in tropical areas

has a life time of more than 30 minutes

has a diameter up to 4 km

is always associated with thunderstorms

23. Which of the following causes echoes on meteorological radar screens?

Any cloud

Hail

Water vapour

Fog

24. Which of the statements is true concerning squall lines?

Severe squall lines always move from northwest to southeast

For severe squall lines a TAF is issued

For severe squall lines a SIGMET is issued

Severe squall lines only occur in the tropics

25. An airborne weather radar installation makes it possible to detect the location of

cumulonimbus, but provided that cloud of this type is accompanied by falls of hail

zones of precipitation, particularly liquid-state precipitation, and also their intensity

all clouds

stratocumulus and its vertical development

26. A microburst phenomenon can arise in the

up draught of a cumulonimbus at the growth stage.

downdraught of a cumulonimbus at the mature stage.

downdraught of a cumulonimbus at the formation stage.

up draught of a cumulonimbus at the mature stage.

27. Large hail stones

only occur in frontal thunderstorms

are entirely composed of clear ice

only occur in thunderstorms of mid-latitudes

are typically associated with severe thunderstorms

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

Frequent lightning

Roll cloud

Continuous updraft

Rain or hail at the surface

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

High air pressure (> 1013 hPa), high temperatures.

High temperatures, high humidity

Low temperatures, low humidity.

Subsidence, inversion.

30. Thunderstorms reach their greatest intensity during the

period in which precipitation is not falling.

dissipating stage.

mature stage.

cumulus stage.

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