Weather

Question 1

What is standard pressure in millibars?

Answer 1

1013.2 mb

Question 2

What is the standard change in temperature and pressure per 1,000 feet?

Answer 2

2 degrees Celcius and one psi

Question 3

What is Coriolis force?

Answer 3

In Northern Hemisphere, where areas of high pressure get deflected to the right when moving into areas of low pressure (ie. wind) and moving to higher altitude.

Question 4

Air circulates ____ around a high pressure area, and ____ around a low

Answer 4

clockwise, counterclockwise

Question 5

Lines denoting areas of equal pressure are called

Answer 5

isobars

Question 6

Which moves faster, a cold or warm front

Answer 6

cold

Question 7

Atmospheric stability is ______

Answer 7

resistance of atmosphere to vertical movement

Question 8

What is difference between ambient temperature lapse rate and adiabatic lapse rate?

Answer 8

Ambient is the actual change in temperature by vertical height, and adiabatic is 3 degrees C/1000 ft

Question 9

What is the dew point lapse rate?

Answer 9

Temperature and dewpoint converge by approximately 4.4 degrees F per 1000 ft

Question 10

What are the four families of clouds?

Answer 10

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

Question 11

What causes sea breezes?

Answer 11

Sea breezes are caused by cool and more dense air moving inland off the water. Once inland over the warmer land, the air heats up and rises. Currents push the air over the water where it cools and descends, starting the process over again

Question 12

A front is _________

Answer 12

A front is the zone of transition (boundary) between two air masses of different density, e.g., the area separating a high pressure system and a low pressure system.

Question 13

There is always a change in ______ across a front

Answer 13

wind

Question 14

The most recognizable change across a front is ______

Answer 14

temperature

Question 15

What are the three phases of a thunderstorm?

Answer 15

Cumulus, mature, dissipating

Question 16

What are the three requirements for a thunderstorm?

Answer 16

Sufficient water vapor, unstable lapse rate, initial upward boost to start the process

Question 17

Structural icing requires which two conditions?

Answer 17

Visible moisture and temperature below or at freezing

Question 18

What two conditions promote mountain waves?

Answer 18

stable air, winds over 40 kts

Question 19

Expect wind sheer in temperature inversion when _____

Answer 19

2,500 to 4,000 AGL, winds at least 25 kts

Question 20

diation fog (shallow fog) is most likely to occur when

Answer 20

there is a clear sky, little or no wind, and a small temperature/dew point spread.

Question 21

Advection fog forms as a result of

Answer 21

moist air condensing as it moves over a cooler surface

Question 22

Upslope fog results from

Answer 22

warm, moist air being cooled as it is forced up sloping terrain

Question 23

Precipitation-induced fog occurs when

Answer 23

warm rain or drizzle falls through cool air and evaporation from the precipitation saturates the cool air and forms fog

Question 24

Steam fog forms _________

Answer 24

in winter when cold, dry air passes from land areas over comparatively warm ocean waters. It is composed entirely of water droplets that often freeze quickly

Question 25

What are two issues associated with steam fog?

Answer 25

Low-level turbulence can occur, and icing can become hazardous in steam fog.

Question 26

What are the four families of clouds?

Answer 26

High clouds Middle clouds Low clouds Clouds with extensive vertical development

Question 27

What is the lapse rate for convective currents?

Answer 27

5.4 degrees F per 1000 ft.

Question 28

The dew point _____ 1 degree F per 1000 ft

Answer 28

decreases

Question 29

What are four characteristics of stable air?

Answer 29

Stratiform clouds Smooth air Fair-to-poor visibility in haze and smoke Continuous precipitation

Question 30

What are four characteristics of unstable air?

Answer 30

Cumuliform clouds Turbulent air Good visibility Showery precipitation

Question 31

Lapse rate means ______

Answer 31

decrease in temperature with increase in altitude

Question 32

Lapse rate is used to determine ______

Answer 32

The stability of air masses

Question 33

What is ballooning effect?

Answer 33

When on final approach, fly over region void of vegetation and convection currents cause you to miss runway

Question 34

What is sinking effect?

Answer 34

When on final approach, you fly over body of water or other cool spot. Causes plane to sink

Question 35

What is adiabatic heating?

Answer 35

When pressure on a gas from external source causes it to heat

Question 36

What is adiabatic cooling?

Answer 36

When air expands, and cools down

Question 37

What is adiabatic?

Answer 37

gas heats or cools without adding or subtracting heat

Question 38

What is a trough?

Answer 38

elongated area of low pressure

Question 39

What is a ridge?

Answer 39

elongated area of high pressure

Question 40

What is a col?

Answer 40

Where ridge and trough intersect

Question 41

What is relative humidity?

Answer 41

water vapor present in air/maximum it can hold at that temperature

Question 42

What is latent heat of evaporation?

Answer 42

cooling of a surface when water evaporates (like precipitation on skin)

Question 43

What is a frontal inversion?

Answer 43

When warm air spreads above cooler air, or colder air is forced under layer of warm air

Question 44

What is difference between radiation fog and advection fog?

Answer 44

The latter requires wind

Question 45

What type of clouds form from advection fog if winds are above 15 kts

Answer 45

stratus

Question 46

Differentiate drizzle from rain

Answer 46

Drizzle is water droplets <0.02 inches, otherwise it is rain

Question 47

What is virga?

Answer 47

rain that evaporates before it hits the ground

Question 48

What two conditions lead to frost on airplane?

Answer 48

Temperature of collecting surface is at or below the dewpoint of the adjacent air and the dewpoint is below freezing