Vayudoot Aviation

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

Stable conditions and high moisture content

Unstable conditions and high moisture content

Unstable conditions and low atmospheric pressure

Stable conditions and low atmospheric pressure

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

Mid - afternoon

Early morning.

Around midnight

Late morning.

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

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

Subsidence, inversion.

Low temperatures, low humidity.

High temperatures, high humidity

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

Mature stage

Dissipating stage

Cumulus stage

In all stages

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

Polar

Temperate

Tropical

Subtropical

6. Thunderstorms reach their greatest intensity during the

mature stage.

dissipating stage.

period in which precipitation is not falling.

cumulus stage.

7. A microburst

occurs only in tropical areas

has a life time of more than 30 minutes

is always associated with thunderstorms

has a diameter up to 4 km

8. 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

all clouds

stratocumulus and its vertical development

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

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

Dissipating stage

Anvil stage

Cumulus stage

Mature stage

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

Any cloud

Hail

Water vapour

Fog

11. What is a microburst?

An extremely strong wind gust in a tropical revolving storm.

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

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

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

12. Where is a squall line to be expected?

In front of a cold front occlusion at higher levels.

Behind a cold front.

In front of an active cold front.

At the surface position of a warm front.

13. Continuous up draughts occur in a thunderstorm during the

mature stage.

dissipating stage

cumulus stage.

period in which precipitation is falling.

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

Strong steady rain

Strong whirlwinds reaching up to higher levels

Thunderstorms

Fog

15. The initial phase of a thunderstorm is characterized by

continuous up draughts

frequent lightning

rain starting at surface

continuous downdraughts

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

400 m

4 km

20 km

50 km

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

Cumulus stage.

Dissipating stage.

Mature stage.

Cumulus stage and mature stage.

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

frontal lifting (warm front).

thermal triggering.

frontal occlusion.

frontal lifting (cold front).

19. Which thunderstorms move forward the fastest?

Thermal thunderstorms.

Thunderstorms formed by lifting processes.

Orographic thunderstorms.

Frontal thunderstorms.

20. 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 can’t conduct a lightning and will therefore very seldom be struck

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 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.

21. A microburst phenomenon can arise in the

downdraught of a cumulonimbus at the formation stage.

up draught of a cumulonimbus at the growth stage.

downdraught of a cumulonimbus at the mature stage.

up draught of a cumulonimbus at the mature stage.

22. A gust front is

formed by the cold air outflow from a thunderstorm

characterized by heavy lightning

normally encountered directly below a thunderstorm

another name for a cold front

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

A stratocumulus cloud with sufficient moisture

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

A cumulus cloud with sufficient moisture associated with an inversion

Water vapour and high pressure

24. Large hail stones

only occur in frontal thunderstorms

only occur in thunderstorms of mid-latitudes

are entirely composed of clear ice

are typically associated with severe thunderstorms

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

Continuous updraft

Rain or hail at the surface

Roll cloud

Frequent lightning

26. Which of the following statements describes a microburst ?

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

An extremely strong wind gust associated with a tropical revolving storm

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

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

27. How long does a typical microburst last?

1 to 5 minutes.

Less than 1 minute.

About 30 minutes.

1 to 2 hours.

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

For severe squall lines a SIGMET is issued

For severe squall lines a TAF is issued

Severe squall lines always move from northwest to southeast

Severe squall lines only occur in the tropics

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

12 km and 5-10 minutes

8 km and 5-15 minutes

4 km and 30-40 minutes

4 km and 1-5 minutes

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

Airmass thunderstorms

Warm front thunderstorms

Occlusion thunderstorms

Cold mass thunderstorms

Question Bank

Questions for THUNDERSTORMS