Aviation Weather

Question 1

What causes every physical process of weather?

Answer 1

Heat exchanges

Question 2

What causes differences in pressure and altimeter settings?

Answer 2

Uneven heating of the Earths surface

Question 3

What causes the developments of thermals?

Answer 3

Solar heating

Question 4

What is a front?

Answer 4

Zone of transitionary between two air masses of different density’s
- e.x. High pressure and low pressure5

Question 5

What kind of air does high pressure consist of?

Answer 5

Area of descending air

Question 6

What kind of air does low pressure area have?

Answer 6

An area of rising air

Question 7

What is the most recognizable change when crossing a front?

Answer 7

The change in temperature and always a change in wind

Question 8

What are the three phases of a Thunderstorm?

Answer 8

Cumulus
Mature
Dissipating

Question 9

What happens during a cumulus stage of a thunderstorm?

Answer 9

The building stage consists of continuous updrafts

Question 10

What happens during the mature stage not a thunderstorm?

Answer 10

Greatest intensity of the thunderstorm, start of precipitation, both updrafts & downdrafts, wing shear, turbulence

Question 11

What happens during the Dissipating stage of a Thunderstorm?

Answer 11

Only downdrafts, storm is raining itself out

Question 12

How is a thunderstorm produced?

Answer 12

By cumulonimbus clouds
- sufficient water vapor
- an unstable lapse rate
- an initial upward boost to start the process

Question 13

Can you fly under the anvil of a thunderstorm?

Answer 13

No, there is still potential for severe clear air turbulence, hail

Question 14

What are the most severe thunderstorm conditions and what are they generally associated with?

Answer 14

The most severe conditions are heavy hair, destructive winds, and tornadoes. They are associated with squall line thunderstorms

Question 15

What is automatically expected with thunderstorms

Answer 15

Lightning bc causes thunder

Question 16

What is a squall line

Answer 16

Non frontal narrow band of thunderstorms

Question 17

What two conditions are need for structural icing?

Answer 17

Visible moisture and temperature at freezing or below

Question 18

What causes the greatest accumulation of structural ice

Answer 18

Freezing rain

Question 19

How does frost form?

Answer 19

Wen temperature of the collecting surface is at or below the dew point of the adjacent air and the dew point is below freezing

Question 20

What happens when there is front on the wings?

Answer 20

Decreases lift, causes friction, and increases drag, may make it impossible to t/o

Question 21

What are lenticular clouds

Answer 21

Almond or lens shaped clouds, may contain winds of 50kts or more, appear stationary, most commonly found on the leeward side of a mountain range

Question 22

When can you expect mountain wave turbulence

Answer 22

Air is stable, and winds of 40kts or more blow across a mountain or ridge

Question 23

What is a rotor cloud

Answer 23

A rotary circulation under each wave crest, the turbulence is most frequent and severe below these clouds

Question 24

When can wind shear occur

Answer 24

Any altitude and can be vertical or horizontal. Most likely with a temp inversion that’s 25kts or Moore while between 2000-4000AGL. Also, any low temp inversions, frontal zones, clear air turbulence

Question 25

What happens when the temp and dew point are within 5 degrees Fahrenheit of each other or less

Answer 25

Expect fog, low clouds

Question 26

What is dew point

Answer 26

Temperature at which the air will have 100 humidity/saturated

Question 27

What determines how much water vapor can be held by the air

Answer 27

Air temperature

Question 28

What is evaporation

Answer 28

Liquid to water vapor

Question 29

What is sublimation

Answer 29

Solid to gaseous state

Question 30

What is deposition

Answer 30

Gaseous state to solid

Question 31

What are the types of fogs

Answer 31

Radiation fog Advection fog Upslope fog Precipitation-induced fog Freezing fog/ice fog Steam fog

Question 32

What is radiation fog

Answer 32

“Morning fog”, clear skies, calm winds, long nights, small temp/dew spread - forms at night when surface cools, causing air above to cool, till early morning and dissipates after sunrise Prone in valleys and lay lying areas

Question 33

What is advection fog

Answer 33

Warm moist air moves over cooler ground/water Forms with strong wind and clouds, shallow and associated with inversions Prone in coastal areas

Question 34

What is upslope fog

Answer 34

Moist air flows upward over rising terrain, causing it to cool to dew point Prone at higher elevations, and build into valleys, high winds, windward side of terrain

Question 35

What is steam fog

Answer 35

Evaporation fog, cold/dry air in contact with warm water, warm water evaporates increasing moisture Prone over bodies of water, early fall or late spring Susceptible to low level turbulence and icing

Question 36

What is freezing fog/ice fog

Answer 36

Saturated air when surface temp is below freezing point Freezing: droplets cannot freeze in air bc lack of nucleus, form at or just below freezing / cold winters, valleys, cold air pools, freeze on impact with surface Ice: ice crystals, below freezing, 0

Question 37

What is precipitation fog

Answer 37

Warm air/drizzle falls through cooler ground air and evaporate and saturates the cool air causing fog Prone with fronts, proximity of icing, turbulence, thunderstorms

Question 38

How are clouds classified and what are their types

Answer 38

Height High clouds, middle clouds, low clouds, and clouds with extensive vertical development

Question 39

What cloud has the greatest turbulence

Answer 39

Cumulonimbus clouds Formed by lifting action, unstable air, moisture

Question 40

What cloud indicate convective turbulence

Answer 40

Towering cumulus

Question 41

What does nimbus mean

Answer 41

Rain

Question 42

What is the temp and dew point converting point

Answer 42

4.4 Fahrenheit / 1000 ft

Question 43

How do you find the base of a cumulus cloud

Answer 43

Find the difference between the dew and temp, then divide it by 4.4.

Question 44

What are unstable characteristic s

Answer 44

Cumuliform clouds, turbulent air, good visibility, showery precipitation, warm, humid

Question 45

What are stable characteristics

Answer 45

Stratiform clouds, smooth air, fair/poor visibility, continuous precipitation, cool ,dry

Question 46

What is a temporal inversion

Answer 46

When air temp increases as altitude increases, stable air, often near ground on clear, calm, cool nights (caused by terrestrial radiation) - smooth air with limited visibility

Question 47

What are cirriform clouds

Answer 47

20000 ft above, composed of ice crystals, thin/white, occur if fair weather and point in direction of air movement

Question 48

What are nimbus clouds

Answer 48

Rain, 7000-12000 ft, bases lower towards the ground when thickened and precipitations falls

Question 49

What are cumuliform clouds

Answer 49

White/fluffy, vertical/uplift formation created by humidity of rising air, more humid means lower the base, can reach 60000ft

Question 50

What are stratiform clouds

Answer 50

“Blanket”, featureless low layer, gray/dull weather, only a few hundred feet AGL (Moist, stable air moving up a mountain) (Steady precipations preceding a front)(

Question 51

What causes instability

Answer 51

When air is warmed below

Question 52

What determines the stability of air masses

Answer 52

Actual lapse rate