Hazards

Question 1

Fog

Answer 1

Visible moisture with base below 50’ and no visible downward motion
–Fog (FG): visibility less than 5/8 SM
–Mist (BR): visibility greater to or equal to ≥ 5/8 SM

Question 2

Fog

Formation Factors

Answer 2

Small temperature/dew point spread

Abundant condensation nuclei

Light surface wind

Cooling land surfaces, warm air above

Question 3

Fog

Cooling Actions

Answer 3

Radiation

Adiabatic

Conduction

Question 4

Fog

Dissipation Factors

Answer 4

Heating

Strong wind

Greenhouse effect/overcast sky

• prevents fog.
• slows fog dissipation

Question 5

Fog

Types

Answer 5

Radiation fog

Advection fog

Precipitation-Induced fog

Upslope fog

Freezing fog

•Ice Fog

Question 6

Radiation Fog

Answer 6

Results from radiation cooling on clear, calm nights

• Relatively shallow
• Light winds
• Midnight to sunrise

Question 7

Advection Fog

Answer 7

Results from surface cooling

• Warm, moist air flowing over a cooler surface
• Deepens with winds 3-9 KTS
• Can be deep, persistent

Question 8

Precipitation-Induced Fog

Answer 8

Results from precipitation falling through cool, unsaturated air

• Ahead of warm front/behind cold front
• Can be quite dense, extend over large areas, and be long-lived

Question 9

Upslope Fog

Answer 9

Results from moist, stable air being lifted by sloping terrain

• Cools adiabatically
• Winds >10 KTS
• May cause cap clouds

Question 10

Freezing Fog

Answer 10

Results when supercooled droplets contact freezing surface

• Supercooled droplets remain liquid until contacting freezing surface
• Sub-freezing temps

Question 11

Ice Fog

Answer 11

Results from extremely cold temperatures and deposition

• Tiny ice crystals suspended in air
• Temps ≤-30°C
• Often seen in Arctic/Polar air

Question 12

Fog

Flight Planning

Answer 12

Consider fog formation at destination.
–Do I have a moisture source?
–Do I have lifting action nearby?
–Is the wind strong enough to dissipate current fog?

Check weather reports.

Pick an alternate airfield.

Ask questions.

Question 13

Icing

Types

Answer 13

Rime Ice
Clear Ice
Mixed Ice
Frost

Question 14

Rime Ice

Answer 14

Forms from small supercooled water droplets

Easy to break loose.

Question 15

Clear Icing

Answer 15

Forms from large supercooled water droplets

Clear, hard and glossy solid ice.

(d) Smooth or rough.

Question 16

Mixed Ice

Answer 16

(a) Combination of rime and clear ice.
(b) Forms rapidly.
(c) Most common from -10° to -15°C.

Question 17

Frost

Answer 17

Ice crystals formed by deposition of water vapor contacting a cold surface

Question 18

Freezing Rain

Answer 18

Freezing rain forms when rain droplets are supercooled by passage through a layer of air which has a sub-zero temperature.

Most dangerous icing condition outside of a thunderstorm

Most common with warm fronts

Question 19

Where would be a likely frontal location to find freezing rain?

Answer 19

Warm fronts

Question 20

Thunderstorms

Development Factors

Answer 20

Unstable or conditionally unstable air
High moisture content
Lifting action

Question 21

Thunderstorms

Types

Answer 21

• Air mass
• Orographic
• Frontal

Question 22

Air Mass

Answer 22

Caused by surface heating

Question 23

Orographic

Answer 23

Caused by terrain effects

Question 24

Frontal

Answer 24

Cold Front, including Squall Lines
Warm Front
Stationary Front
Occluded Front

Question 25

Thunderstorms | Cumulus Stage

Answer 25

(a) Vertical currents --all upward. (b) Temperature distribution -- warmer in cloud than outside. (c) Turbulence -- light to moderate. (d) Surface winds -- gusty and variable. (e) Precipitation - -none outside of cloud.

Question 26

Mature stage

Answer 26

begins when precipitation starts (a) Vertical currents -- possible 6,000 F.P.M. up and 4,000 F.P.M. down. (b) Temperature distribution -- warmer in updraft areas and colder in downdraft areas. (c) Turbulence (most severe in mid-altitude levels). (d) Surface winds -- strong and gusty (e) Precipitation -- heavy rain showers. ``` Begins when precip starts •Vertical currents – possible 6,000 fpm up/4,000 fpm down – Most turbulent stage •Temp distribution – warmer in updraft areas, colder in downdraft areas •Surface winds – strong and gusty •Precip – heavy rain showers •Average height – 25,000’ at start of mature stage ```

Question 27

Dissipating stage

Answer 27

(a) Vertical currents -- all downward. (b) Temperature distribution -- colder in cloud than outside. (c) Turbulence -- moderate to severe. (d) Surface winds -- strong and gusty. (e) Precipitation -- heavy rain showers decreasing to light to none.

Question 28

What type of TS is created as moist air lifts to the LFC near a mountain range?

Answer 28

Orographic TS

Question 29

Which stage of a TS is described as being the most turbulent and having both up and down drafts?

Answer 29

Mature Stage

Question 30

Microbursts

Answer 30

short-lived, powerful downburst of air associated with convective activity with diameters up to ½ mile, lasting 5 – 15 minutes. (1) Winds extending out up to 2.5 miles (2) Most commonly occur: - Mid-summer - Between 11 am and 4 pm - With cloud tops between 10,000' and 20,000'

Question 31

Wet microburst

Answer 31

– A typical wet-microburst is produced from a cumulus cloud with heavy rain. A descending wet microburst may first appear as a darkened mass of rain descending through light rain. Has rain

Question 32

Dry microburst

Answer 32

– A typical dry microburst is produced from a cumulus cloud with little or no surface rain. In extremely dry situation, the storm will normally produce virga. The dry-microburst may have a ring of dust under the base of the cloud, indicating the surface position. Has Virgo

Question 33

What are the four conditions necessary for the formation of fog.

Answer 33

a. light surface wind b. small temperature/dewpoint spread c. condensation nuclei d. cooling land surfaces

Question 34

What are the dissipation factors of fog?

Answer 34

a. heating b. strong wind c. greenhouse effect/overcast sky

Question 35

What type of cooling action causes radiation fog to form?

Answer 35

radiation cooling

Question 36

Describe the formation and typical location of precipitation-induced fog

Answer 36

Precipitation-induced fog is created as rain falls through a frontal inversion and saturates the cooler air below. It is typically found ahead of a warm front or behind a cold front

Question 37

What type of fog is formed through the process of deposition?

Answer 37

ice fog

Question 38

The 2400L forecast report (TAF) for your destination airport predicts the sky CLR, wind at 4 knots, temperature of 17°, and a dew point 15°. You will arrive at this destination shortly after midnight. What weather (by METAR coding) would you expect to encounter upon arrival?

Answer 38

FG

Question 39

Question 6 (The 2400L forecast report (TAF) for your destination airport predicts the sky CLR, wind at 4 knots, temperature of 17°, and a dew point 15°. You will arrive at this destination shortly after midnight. What weather (by METAR coding) would you expect to encounter upon arrival?) Referring back to question 6: Assume the same conditions exist, except the forecast wind for 2400L was stronger --12-15 knots. (There is no body of water nearby.) What kind of weather would you expect? Why?

Answer 39

Clear skies would be expected because the strong wind would tend to prevent or dissipate any fog.

Question 40

Your December mission is taking you to Tyndall AFB, KPAM, along the Florida Gulf Coast. The ground is cold. Warm, moist air is flowing inland (at 3-9 kts) from the Gulf of Mexico. You would expect ______ (type) fog to form, possibly covering a ____ area.

Answer 40

advection; large

Question 41

Moist, stable air is being forced up an incline, expanding and cooling as it is lifted. What type of fog will occur when this air reaches the saturation point?

Answer 41

upslope

Question 42

Fog has formed during the late evening hours. Before sunrise, a thick overcast layer of clouds moves in over the fog. What effect will this have on the dissipation of this fog?

Answer 42

The OVC cloud layer will slow the dissipation of the fog.

Question 43

What type of icing is described as small supercooled water droplets in temperatures -8° to -10° and stratus clouds?

Answer 43

rime

Question 44

Clear icing will typically occur in cumulus clouds where supercooled water droplets are _____ than those in stratiform clouds.

Answer 44

larger

Question 45

What intensity of icing would require immediate diversion from the affected altitudes?

Answer 45

severe

Question 46

Where is a common frontal location to find freezing rain (during the winter months)?

Answer 46

warm front

Question 47

In addition to being a hazard to vision by covering windshields, ice can cause a loss of vital airspeed readings by covering the _______.

Answer 47

pitot tube

Question 48

What factors are needed for a thunderstorm to form?

Answer 48

Unstable air, small temperature/dewpoint spread, lifting action

Question 49

What type of frontal thunderstorm would match the definition of "A severe line of thunderstorms that form ahead of a fast moving cold front"?

Answer 49

squall line

Question 50

A summertime thunderstorm is building over your stagefield, just as it has done every day for the past week about 3 pm. What type of thunderstorm is forming?

Answer 50

air mass

Question 51

The windward side of the mountain range has vertical clouds developing into a thunderstorm. What type of thunderstorm is forming?

Answer 51

orographic

Question 52

The three stages of thunderstorm, in the order of development, are

Answer 52

cumulus mature dissipating

Question 53

The most sever weather would occur in which stage of a thunderstorm?

Answer 53

mature

Question 54

How do you know the cumulus stage has ended and the mature stage has begun?

Answer 54

Precipitation and downdrafts are descending from the cloud.

Question 55

In the developments of a thunderstorm, only updrafts are found in the ____stage.

Answer 55

cumulus

Question 56

What is the recommended flight procedure in the vicinity of a thunderstorm?

Answer 56

circumnavigate or land

Question 57

A microburst occurring in the heavy rain shaft of a thunderstorm would be classified as a ____ microburst,t

Answer 57

wet

Question 58

A microburst with virga from under vertical clouds would be classified as a ___ microburst.

Answer 58

dry

Question 59

# Choose the best conditions for a dry microburst to happen near KOZR: a. ST clouds, 08:00CST, December 18 b. CU clouds, 14:00CST, July 14 c. AS clouds, 21:00CST, May31 d. CI clouds, 12:00CST, February 20

Answer 59

b. CU clouds, 14:00CST, July14