Weather 1 Flashcards
In what part of the atmosphere does most weather occur?
Troposphere.
The most frequent type of ground based or surface based temperature inversion is produced by
Terrestrial radiation on a clear, relatively still night
In tile Northern Hemisphere, a pilot making a long distance flight from east to west would most
likely find favorable winds associated with high-and low-pressure systems by flying to the
south of a high and to the north of a low
The general circulation of air associated with a high-pressure area in the Northern
Hemisphere is
outward, downward, and clockwise
which us an operational considerations regarding actual air temperature and dewpoint?
The temperature spread decreases as the relative humidity increases
The ratio of the existing water vapor in the air, as compared to the maximum amount that could exist at a given temperature, is called
relative humidity.
What is the process by which ice can form on a surface directly from water vapor on a cold, clear night?
Sublimation
From which measurement of the atmosphere can stability be determined?
Ambient lapse rate.
At approximately what altitude above the surface would you expect the base of cumuliform clouds if the surface air temperature is 77°F and the dewpoint is 53”F?
77 - 53 =24
divide by the degrees F convergence rate of 4.4 f 4.4 per 1,000 ft. 24 / 4.4 - 5.45 So 5.45 thousands of feet, or 5450 feet
At approximately what altitude above the surface would You expect the base of cumuliform clouds if the surface air temperature is 33 C and the dew point is 15C
33 - 15 = 18, and divide by the degrees C convergence rate of
2.5 per 1,000 ft. 18 / 2.5 - 7.2 So 7.2 thousands of feet, or 7,200 feet
The height of the bases of the middle clouds in the middle latitudes ranges from
6,500 to 23,000 feet.
Which middle level clouds are characterized by rain, snow, or ice pellets posing a serious icing problem if temperatures are near or below freezing?
Nimbostratus.
A moist air mass, which is colder than the surface over which it passes, frequently has which of
the above characteristics?:
1. Cumuliform clouds.
2. Stable lapse rate.
3. Unstable lapse rate.
4. Stratiform clouds and fog.
5. Smooth air (above the friction level) and poor visibility.
6. Turbulence up to about 10,000 feet and good visibility except in areas of precipitation.
1,3,6
The weather condition normally associated with unstable air is
good visibility, except in blowing sand or snow.
Frontal waves normally form on
slow-moving cold fronts or stationary fronts.
Cool air moving over a warm surface is generally characterized by
instability and showers.
Which statement is true regarding a cold front occlusion?
The air ahead of the warm front is warmer than the air behind the overtaking cold front
Low-level wind shear, which results in a sudden change of wind direction, may occur
when there is a \ow-level temperature inversion with strong winds above the inversion
Which condition could be expected if a strong Temperature inversion exists near the surface?
A wind shear with the possibility of sudden loss of airspeed
The most rapid accumulation of clear ice on an aircraft in flight occur with temperatures
between 0to -15°C in
cumuliform clouds.
Which is an operational consideration regarding aircraft structural icing?
In order for structural ice to form the temperatures at the point where moisture strikes the aircraft must be ) 0 C or colder
Tornadoes are most likely to occur with which type of thunderstorms?
Steady state thunderstorms associated with cold fronts or squall lines
Which type of cloud is associated with violent turbulence and a tendency toward the
production of funnel clouds?
Cumulonimbus mamma
Choose the correct ones for hail?
- There is a correlation between the visual appearance of thunderstorms and the amount of hail within them
- Large hail is most commonly found in thunderstorms which have strong updrafts and large liquid content.
- Hail maybe found at any level within at thunderstorm but not in the clear air outside of the storm cloud.
- Hail is usually produced during the mature stage of the thunderstorm’s life span.
- Hailstones may be thrown upward and outward from a storm cloud for several miles.
2,4,and 5