Thunderstorms Flashcards
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.
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.
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.
C) Sufficient water vapor, unstable air, and lifting action.
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.
B) Towering cumulus, mature, and dissipating.
Typical life cycle of a thunderstorm is about
a) 30 minutes.
b) 15 minutes.
c) 1 hour.
A) 30 minutes.
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.
C) A strong convective updraft.
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.
B) Precipitation reaches the ground.
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.
A) True
Cumulonimbus tops rarely penetrate into the lower stratosphere where upper winds distort the cloud top into an anvil shape.
a) True.
b) False.
B) False
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.
A) Toward the end of the mature stage.
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.
C) A strong downdraft within the area of precipitation.
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.
B) Single-cell, multi-cell, and super cell.
All types of thunderstorms are hazardous to aircraft.
a) True.
b) False.
A) True.
Only super-cell thunderstorms are hazardous to aircraft; single- and multi-cell thunderstorms present no danger.
a) True.
b) False.
B) False.
Multi-cell thunderstorms are rare, most are single-cell thunderstorms.
a) True.
b) False.
B) False
Single-cell thunderstorms are rare, almost all thunderstorms are multi-cell.
a) True.
b) False.
A) True
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.
A) As the first cell matures, it is carried downwind, and a new cell forms upwind to take its place.
About 25% of all U.S. tornadoes are spawned by squall line thunderstorms.
a) True.
b) False.
a) True
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
C) Often dangerous convective storm that consists primarily of a single, quasi-steady rotating updraft that persists for an extended period of time
Thunderstorm motion equals the combined effects of both
a) Dissipation and wind direction.
b) Advection and propagation.
c) Radiation cooling and wind direction.
B) Advection and propagation.
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.
A) Individual cells moving with the average wind throughout the vertical depth of the cumulonimbus cloud.
Thunderstorm motion may deviate substantially from the motion of the individual cells which comprise the storm.
a) True.
b) False.
A) True
Thunderstorm motion never deviates from the motion of the individual cells which comprise the storm.
a) True.
b) False.
B) False
Hazards associated with thunderstorms include
a) Rapid altimeter changes and static electricity.
b) Lightning and adverse winds.
c) All are correct.
C) All are correct.
Hazards associated with thunderstorms include
a) Downbursts and turbulence.
b) Icing and hail.
c) All are correct.
C) All are correct.
The lightning discharge associated with a thunderstorm may
a) Occur between clouds.
b) Between the cloud and air.
c) All are correct.
C) All are correct.
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.
A) Along and immediately behind the gust front.
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.
B) The leading edge of cool air rushing down and out of a thunderstorm.
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.
C) Several thousand feet above, and 20 miles laterally from, a severe storm.
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.
A) Gust front shear zone associated with a thunderstorm.
Thunderstorms produce abundant supercooled liquid water above the freezing level.
a) True.
b) False
A) True
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.
A) Strong updrafts, large supercooled liquid water contents, large cloud-drop sizes, and great vertical height.
When viewed from the air, it is evident that hail falls in paths known as
a) Hail paths.
b) Hail zones.
c) Hail swaths.
C) Hail swaths.
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.
B) Intense corona discharges from sharp metallic points and edges of flying aircraft and is often encountered in the vicinity of thunderstorms.
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.
B) In the central and eastern U.S. during spring afternoons and evenings.
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.
A) True
You should avoid a severe thunderstorm by
a) 5 miles.
b) 15 miles.
c) 20 miles.
C) 20 miles.
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.
A) Plan and hold course to take the aircraft through the storm in a minimum time.
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.
A) If using an automatic pilot, disengage altitude hold mode; this will decrease airframe structural stress.
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.
B) Maintain constant attitude; allow the altitude and airspeed to fluctuate.
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.
C) Outside the cloud, shear turbulence can be encountered 20 miles laterally from a severe storm.
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.
C) At least 20 miles.
