Thunderstorms

Question 1

A thunderstorm is a local storm,

a) Invariably produced by a cumulonimbus cloud, and always accompanied by lightning and thunder, usually with strong gusts of winds, heavy rain, and sometime with hail.

b) Invariably produced by a towering stratiform cloud, and may be accompanied by lightning, hail, and strong gusts of wind.

c) Invariably produced by a towering cumuliform cloud, and may be accompanied by lightning and thunder and heavy rain with hail.

Answer 1

A) Invariably produced by a cumulonimbus cloud, and always accompanied by lightning and thunder, usually with strong gusts of winds, heavy rain, and sometime with hail.

Question 2

Thunderstorm cell formation requires three ingredients

a) Some moisture content, stable air, and lifting action.

b) Sufficient water vapor, stable air, and lifting action.

c) Sufficient water vapor, unstable air, and lifting action.

Answer 2

C) Sufficient water vapor, unstable air, and lifting action.

Question 3

Three distinct stages of a thunderstorm’s life cycle are

a) Towering stratus, fully developed, and final dissipation.

b) Towering cumulus, mature, and dissipating.

c) Cumulonimbus, precipitation, and downdrafts.

Answer 3

B) Towering cumulus, mature, and dissipating.

Question 4

Typical life cycle of a thunderstorm is about

a) 30 minutes.

b) 15 minutes.

c) 1 hour.

Answer 4

A) 30 minutes.

Question 5

The distinguishing feature of the towering cumulus stage of a thunderstorm is

a) The beginning of precipitation.

b) Strong downdrafts.

c) A strong convective updraft.

Answer 5

C) A strong convective updraft.

Question 6

A thunderstorm cell transitions to the mature stage when

a) A strong convective updraft develops.

b) Precipitation reaches the ground.

c) A strong downdraft develops.

Answer 6

B) Precipitation reaches the ground.

Question 7

Cumulonimbus tops frequently penetrate into the lower stratosphere as an overshooting top, where strong winds aloft distort the cloud top into an anvil shape.

a) True.

b) False.

Answer 7

A) True

Question 8

Cumulonimbus tops rarely penetrate into the lower stratosphere where upper winds distort the cloud top into an anvil shape.

a) True.

b) False.

Answer 8

B) False

Question 9

During a thunderstorm, weather hazards reach peak intensity

a) Toward the end of the mature stage.

b) During the beginning of the mature stage.

c) At the end of the dissipating stage.

Answer 9

A) Toward the end of the mature stage.

Question 10

The dissipating stage of a thunderstorm is marked by

a) A strong convective updraft.

b) The beginning of precipitation.

c) A strong downdraft within the area of precipitation.

Answer 10

C) A strong downdraft within the area of precipitation.

Question 11

There are three principal thunderstorm types,

a) Local, wide-area, and squall line.

b) Single-cell, multi-cell, and super cell.

c) Light, strong, and severe.

Answer 11

B) Single-cell, multi-cell, and super cell.

Question 12

All types of thunderstorms are hazardous to aircraft.

a) True.

b) False.

Answer 12

A) True.

Question 13

Only super-cell thunderstorms are hazardous to aircraft; single- and multi-cell thunderstorms present no danger.

a) True.

b) False.

Answer 13

B) False.

Question 14

Multi-cell thunderstorms are rare, most are single-cell thunderstorms.

a) True.

b) False.

Answer 14

B) False

Question 15

Single-cell thunderstorms are rare, almost all thunderstorms are multi-cell.

a) True.

b) False.

Answer 15

A) True

Question 16

With an organized multi-cell cluster thunderstorm,

a) As the first cell matures, it is carried downwind, and a new cell forms upwind to take its place.

b) As the first cell dissipates, it is carried upwind, and a new cell forms downwind to take its place.

c) As the first cell begins to build, it is carried upwind and caused multiple cells to build simultaneously.

Answer 16

A) As the first cell matures, it is carried downwind, and a new cell forms upwind to take its place.

Question 17

About 25% of all U.S. tornadoes are spawned by squall line thunderstorms.

a) True.

b) False.

Answer 17

a) True

Question 18

A supercell thunderstorm is an

a) Often dangerous convective storm that consists primarily of multiple, steady rotating downdrafts that persists for an extended period of time.

b) Ineffective storm with minimal convective currents and lasts approximately 30 minutes.

c) Often dangerous convective storm that consists primarily of a single, quasi-steady rotating updraft that persists for an extended period of time

Answer 18

C) Often dangerous convective storm that consists primarily of a single, quasi-steady rotating updraft that persists for an extended period of time

Question 19

Thunderstorm motion equals the combined effects of both

a) Dissipation and wind direction.

b) Advection and propagation.

c) Radiation cooling and wind direction.

Answer 19

B) Advection and propagation.

Question 20

In relation to thunderstorm movement; advection is the component of the storm motion due to

a) Individual cells moving with the average wind throughout the vertical depth of the cumulonimbus cloud.

b) Multiple cells moving with wind gusts throughout the horizontal plane of the cumulonimbus cloud.

c) Individual cells moving with wind gusts throughout the horizontal plane of the cumulonimbus cloud.

Answer 20

A) Individual cells moving with the average wind throughout the vertical depth of the cumulonimbus cloud.

Question 21

Thunderstorm motion may deviate substantially from the motion of the individual cells which comprise the storm.

a) True.

b) False.

Answer 21

A) True

Question 22

Thunderstorm motion never deviates from the motion of the individual cells which comprise the storm.

a) True.

b) False.

Answer 22

B) False

Question 23

Hazards associated with thunderstorms include

a) Rapid altimeter changes and static electricity.

b) Lightning and adverse winds.

c) All are correct.

Answer 23

C) All are correct.

Question 24

Hazards associated with thunderstorms include

a) Downbursts and turbulence.

b) Icing and hail.

c) All are correct.

Answer 24

C) All are correct.

Question 25

The lightning discharge associated with a thunderstorm may a) Occur between clouds. b) Between the cloud and air. c) All are correct.

Answer 25

C) All are correct.

Question 26

Adverse winds associated with a thunderstorm are normally located a) Along and immediately behind the gust front. b) Directly underneath the anvil top of the towering cumulonimbus. c) Behind the cell, within 15 SM.

Answer 26

A) Along and immediately behind the gust front.

Question 27

A gust front associated with a thunderstorm is a) The trailing edge of warm rushing up and into a thunderstorm. b) The leading edge of cool air rushing down and out of a thunderstorm. c) The leading edge of warm air rushing up and out of a thunderstorm.

Answer 27

B) The leading edge of cool air rushing down and out of a thunderstorm.

Question 28

Outside the thunderstorm cumulonimbus cloud, turbulence has been encountered a) Several hundred feet below, and 5 miles laterally from, a severe storm. b) Directly below a severe storm. c) Several thousand feet above, and 20 miles laterally from, a severe storm.

Answer 28

C) Several thousand feet above, and 20 miles laterally from, a severe storm.

Question 29

Sometimes a shelf cloud will form to indicate the a) Gust front shear zone associated with a thunderstorm. b) Impending towering cumulus stage of a thunderstorm. c) Dissipating stage of a thunderstorm has begun.

Answer 29

A) Gust front shear zone associated with a thunderstorm.

Question 30

Thunderstorms produce abundant supercooled liquid water above the freezing level. a) True. b) False

Answer 30

A) True

Question 31

What thunderstorm characteristics are favorable for the formation of hail? a) Strong updrafts, large supercooled liquid water contents, large cloud-drop sizes, and great vertical height. b) Moderate updrafts, small supercooled liquid water contents, moderate cloud-drop sizes, and average vertical height. c) All thunderstorms produce hail.

Answer 31

A) Strong updrafts, large supercooled liquid water contents, large cloud-drop sizes, and great vertical height.

Question 32

When viewed from the air, it is evident that hail falls in paths known as a) Hail paths. b) Hail zones. c) Hail swaths.

Answer 32

C) Hail swaths.

Question 33

Static electricity, a steady, high level of noise in radio receivers, is caused by a) Lightning. b) Intense corona discharges from sharp metallic points and edges of flying aircraft and is often encountered in the vicinity of thunderstorms. c) Surface friction between the aircraft airfoil and precipitation and is only encountered when flying directly through a thunderstorm.

Answer 33

B) Intense corona discharges from sharp metallic points and edges of flying aircraft and is often encountered in the vicinity of thunderstorms.

Question 34

Tornadoes can occur almost anywhere in the world, but are most common a) Along the western U.S. coast. b) In the central and eastern U.S. during spring afternoons and evenings. c) In the southeastern U.S. during spring mornings and afternoons.

Answer 34

B) In the central and eastern U.S. during spring afternoons and evenings.

Question 35

Don’t use data-linked weather next generation weather radar (NEXRAD) mosaic imagery as the sole means for negotiating a path through a thunderstorm area (tactical maneuvering). a) True. b) False.

Answer 35

A) True

Question 36

You should avoid a severe thunderstorm by a) 5 miles. b) 15 miles. c) 20 miles.

Answer 36

C) 20 miles.

Question 37

If you cannot avoid penetrating a thunderstorm, a) Plan and hold course to take the aircraft through the storm in a minimum time. b) Try to bank sharply to get the aircraft out of the storm as soon as possible. c) Enter an autorotation, as this will get the aircraft out of the storm cell in a minimum amount of time.

Answer 37

A) Plan and hold course to take the aircraft through the storm in a minimum time.

Question 38

If you cannot avoid penetrating a thunderstorm, a) If using an automatic pilot, disengage altitude hold mode; this will decrease airframe structural stress. b) If using an automatic pilot, engage altitude hold mode; this will decrease airframe structural stress. c) If using an automatic pilot, engage altitude hold mode upon initial entry into the cell, then disengage altitude hold mode when exiting the cell.

Answer 38

A) If using an automatic pilot, disengage altitude hold mode; this will decrease airframe structural stress.

Question 39

After inadvertently penetrating a thunderstorm, a) Maintain altitude and airspeed, minimize fluctuations. b) Maintain constant attitude; allow the altitude and airspeed to fluctuate. c) Engage altitude hold mode on the auto pilot.

Answer 39

B) Maintain constant attitude; allow the altitude and airspeed to fluctuate.

Question 40

Of the following, which is accurate regarding turbulence associated with thunderstorms? a) Outside the cloud, shear turbulence can be encountered 50 miles laterally from a severe storm. b) Shear turbulence is encountered only inside cumulonimbus clouds or within a 5-mile radius of them. c) Outside the cloud, shear turbulence can be encountered 20 miles laterally from a severe storm.

Answer 40

C) Outside the cloud, shear turbulence can be encountered 20 miles laterally from a severe storm.

Question 41

Thunderstorms identified as severe or giving an intense radar echo should be avoided by what distance? a) 5 miles. b) At least 25 miles. c) At least 20 miles.

Answer 41

C) At least 20 miles.