For Question 391 select "B", "C" or "D" ("A" is selected only as an example)!
391. A temperature inversion would most likely result in which weather condition?
A) None of the below. B) Cloluds with extensive vertical development above an inversion aloft. C) Good visibility in the lower levels of the atmosphere and poor visibility above an inversion aloft. D) An increase in temperature as altitude is increased.
392. The most frequent type of ground or surface-based temperature inversion is that which is produced by:
A) terrestrial radiation on a clear, relatively still night. B) warm air being lifted rapidly aloft in the vicinity of mountainous terrain. C) the movement of colder air under warm air, or the movement of warm air over cold air. D) None of the above.
393. Which weather conditions should be expected beneath a low-level temperature inversion layer when the relative humidity is high?
A) Smooth air, poor visiblity, fog, haze, or low clouds. B) Light wind shear, poor visibility, haze and light rain. C) Turbulent air, poor visibility, fog, low stratus type clouds, and showery precipitation. D) None of the above.
394. Which weather phenomenon signals the beginning of the mature stage of a thunderstorm?
A) The appearance of an anvil top. B) Precipitation beginning to fall. C) Maximum growth rate of the clouds. D) None of the above.
395. The conditions necessary for the formation of cumulonimbus clouds are a lifting actiona and:
A) unstable air containing an excess of condensation nuclei. B) unstable, moist air. C) either stable or unstable air. D) None of the above.
396. What conditions are necessary for the formation of thunderstorms?
A) High humidity, lifting force, and unstable conditions. B) High humidity, high temperature, and cumulus clouds. C) Lifting force, moist air, and extensive cloud cover. D) None of the above.
397. During the life cycle of a thunderstorm, which stage is characterized predominately by downdrafts?
A) Cumulus. B) Dissipating. C) Mature. D) None of the above.
398. Thunderstorms reach their greatest intensity during the:
A) mature stage. B) downdraft stage. C) mature. D) None of the above.
399. Thunderstorms which generally produce the most intense hazard to aircraft are:
A) squall line thunderstorms. B) steady-state thunderstorms. C) warm front thunderstorms. D) None of the above.
400. A nonfrontal, narrow band of active thunderstorms that often develop ahead of a cold front is known as a:
A) prefrontal system. B) squall line. C) dry line. D) None of the above.