METEO Chapter 10
) Dual-polarization technology as allowed Doppler Radar to: A) better identify the type, size, intensity, and location of precipitation. B) identify tornadic rotation for the first time. C) assess the EF-scale rank of a tornado. D) sense motion that is occurring perpendicular to the radar beam.
A
) In the United States, a mesoscale convective complex is most likely to develop in: A) the Great Plains. B) the Pacific Northwest. C) New England. D) the Gulf of Mexico.
A
) The Enhanced -Fujita Intensity Scale (EF-scale) is applied to: A) tornadoes. B) typhoons. C) lightning. D) thunderstorms.
A
A microburst is: A) another name for a downburst. B) rarely damaging. C) associated only with tornadic thunderstorm cells. D) a brief, intense explosion of lightning
A
About what percent of thunderstorms in the United States become severe? A) 10% B) 20% C) 25% D) 50%
A
All of the following can form in association with the gust front EXCEPT: A) mesocyclones B) roll cloud C) shelf cloud D) new developing thunderstorm cells
A
An air mass thunderstorm rarely lives long enough to create very severe weather because: A) the downdrafts quickly become strong enough to stop the updraft and influx of moisture to the storm. B) the atmosphere is generally fairly stable when these storms develop. C) there is rarely enough moisture available to keep the storm alive for longer than 30 minutes. D) wind shear causes the storm's updraft to become tilted
A
Any of the following conditions can cause a thunderstorm to be classified as severe EXCEPT: A) roll clouds preceding the gust front B) winds in excess of 93 km/hr (58 mph) C) hailstones larger than 2.5 cm (1 inch) in diameter D) tornado
A
At what time of day is an air-mass thunderstorm more likely to develop? A) midafternoon B) midnight C) midmorning D) pre-dawn
A
Downdrafts totally dominate the ________ of an air mass thunderstorm. A) dissipating stage B) mature stage C) cumulus stage
A
Drylines are capable of producing thunderstorms because: A) the dry air mass forces the moist air mass to rise. B) the moist air mass lifts the dry air mass. C) there is an abrupt change in temperature across the dryline. D) the dry air mass is unstable and rising.
A
During the formation of a lightning strike, a ________ is emitted from the surface and connects with the channel mid-air in order to complete the path for electrons to travel into the ground. A) streamer B) leader C) stepped leader D) return stroke
A
Generally there are three stages involved in the development of ordinary (or air mass) thunderstorms. They are: A) cumulus stage, mature stage, and dissipating stage. B) cumulus stage, mature stage, and de constructing stage. C) cumulus stage, adolescent stage, and dissipating stage. D) cumulus stage, dissipating stage, and de constructing stage.
A
Multiple-vortex tornadoes help explain: A) why one building is destroyed and the one next to it is untouched. B) why tornadoes are so short lived. C) why some tornadoes never touch the ground. D) what EF rank a tornado should have.
A
Ordinary, or air-mass, thunderstorms usually form in association with ________ air masses. A) mT B) mP C) cT D) cP
A
The Enhanced Fujita scale is based on: A) the level of damage caused by a tornado. B) the measured wind speeds inside a tornado. C) the pressure gradient across the diameter of a tornado. D) the frequency of lightning strikes concurrent with the tornado.
A
The NWS branch charged specially with providing forecasts and watches for severe weather is called the: A) Storm Prediction Center (SPC). B) Severe Weather Forecast Office (SWF). C) Tornado Prediction Office (TP). D) Severe Outlook Service (SOS).
A
The greatest number of deaths associated with thunderstorms result from: A) flash flooding. B) lightning. C) hail. D) tornadoes.
A
The total discharge of lightning is made up of several rapid strokes and is known as the: A) flash. B) strike. C) bolt. D) leader.
A
Updrafts dominate the cumulonimbus cloud during the ________ in the life cycle of an air mass thunderstorm. A) cumulus stage B) dissipating stage C) mature stage
A
What does the term mesocyclone refer to? A) the rotation of the updraft in the parent thunderstorm B) a high-altitude tornado C) a false-alarm tornado warning D) a very large tornado
A
What is entrainment? A) the process of cool, dry air being pulled into a thunderstorm by the downdraft B) warm, moist air fed into a thunderstorm by the updraft C) rotation from the parent cloud transferring into a tornado D) a line of thunderstorms, one feeding into the next
A
What key change does wind shear promote in a thunderstorm that helps extend its life span? A) It causes the storm to become tilted. B) It causes the overshooting top to form. C) It creates the gust front. D) It helps hailstones to grow larger.
A
Which association is incorrect? A) tornado watch — a tornado has been sighted on the ground B) downdraft — precipitation C) anvil - front of the thunderstorm D) mesocyclone — region of tornado formation
A
Which of the following U.S. states experiences the most thunderstorms each year? A) Florida B) Texas C) Colorado D) Oklahoma
A
Which of the following is the key ingredient required in order to transform ordinary thunderstorms into mesoscale convective complexes? A) a strong low-level flow of warm, moist air B) large quantities of entrainment C) convergence aloft D) a warm-type occluded front
A
Which of the following thunderstorm features will typically only develop if vertical directional shear is present? A) the mesocyclone B) the gust front C) the overshooting top D) the downdraft
A
Why are air mass thunderstorms most likely to occur in the midafternoon? A) Atmosphere is most unstable at that time. B) Upper-level winds are too fast at night and in morning. C) Water-vapor contents are too low at night. D) It takes all day for them to mature.
A
Why do most tornadoes in the central U.S. occur during the spring months? A) Air-mass contrasts are greatest. B) Divergence of air aloft is greatest. C) Solar energy is a maximum. D) Surface air is most humid. E) Upper-air temperatures are warmest.
A
________ is defined as a significant change in wind speed and/or wind direction with increasing height above the surface
A
An overshooting top means that: A) a thunderstorm will definitely produce a tornado. B) the thunderstorm has very strong updrafts causing the cloud to grow into the stratosphere. C) the thunderstorm is dissipating. D) lightning strikes will be especially intense.
B
Because air is a poor conductor of electricity, what must be true before lightning can strike? A) surfaces on the ground must become wet with rainfall. B) the electrical potential between the regions of opposite charges must be very high. C) the cloud must be less than 5 km (16,000 feet) tall. D) two mesocyclones must be in very close proximity to one another.
B
Because of the tremendous pressure gradient associated with a strong tornado, maximum winds approach ________ miles per hour. A) 100 B) 300 C) 600 D) 1000
B
Downdrafts and updrafts found side by side occur during the ________ in the life cycle of an air mass thunderstorm. A) dissipating stage B) mature stage C) cumulus stage
B
Extreme evaporative cooling can sometimes produce explosions of straight-line winds called: A) gust fronts. B) down bursts. C) tornadoes. D) air bombs.
B
Hurricanes and thunderstorms can sometimes cause rapidly rising local floods that are shortlived but high volume. These are called: A) rapid floods. B) flash floods. C) 100-year floods. D) surge floods.
B
In which of the following places are thunderstorms most common? A) central Nevada B) central Florida C) northern Wisconsin D) west of Hudson Bay (Canada) E) The occurrence of thunderstorms at all of these places should be about the same.
B
More than half of all the flash-flood deaths occurring in the United States: A) happen in the early morning hours. B) are auto related. C) occur in the winter when people are not expecting severe weather and are less aware. D) occur during mesoscale convective complexes.
B
Severe convective outlooks: A) are only issued when supercell thunderstorms are present. B) are issued several times daily and describe the types, coverage, and likelihood of severe weather expected across the United States. C) should cause people to take immediate shelter when they are issued. D) are only issued as needed by individual forecast offices across the country.
B
The diameter of a typical tornado funnel cloud would be: A) 50 - 100 meters. B) 150 - 600 meters. C) 1000 - 2500 meters. D) 3000 meters.
B
The leading edge of a gust front is frequently associated with: A) heavy precipitation. B) the development of a new cumulonimbus cloud. C) tornadoes. D) hail.
B
Which of the following demonstrates the correct order of the phases involved in a lightning stroke? A) Step leaders, return stroke, separation of charges, flow of negative charge into ground, dart leader B) Charge separation, step leaders, return stroke, flow of negative charge into ground, dart leader C) Dart leader, charge separation, flow of negative charge into ground, step leaders, return stroke D) Charge separation, dart leader, step leaders, flow of negative charge into ground, return stroke
B
Which of the following statements is not true of tornadoes? A) generally move from the southwest toward the northeast B) usually occur along the warm front of a midlatitude cyclone C) associated with cumulonimbus clouds D) occur most frequently in the spring of the year
B
Which type of lightning is least likely? A) within the same cloud B) cloud-to-Earth C) cloud-to-cloud
B
Why do most tornadoes tend to travel in the same general direction? A) Because of their clockwise rotation. B) They generally occur in a zone of southwest winds. C) They have an intense pressure gradient force. D) Tornadoes often occur to the east of the center of a midlatitude cyclone.
B
) A tornado that does devastating damage and has estimated wind speeds of 300 km/hr (186 mph) would be ranked as an: A) EF-2. B) EF-3. C) EF-4. D) EF-5.
C
2) At any given time, about how many thunderstorms are in progress on Earth? A) 45 B) 500 C) 2,000 D) 45,00
C
In the development of a thunderstorm, sharp and cool gusts beginning at the surface are characteristic in the: A) cumulus stage. B) dissipating stage. C) mature stage.
C
Mesoscale convective complexes: A) do not provide any benefit to agriculture. B) occur along dry lines. C) begin as air mass thunderstorms that form in the afternoon. D) tend to die out as soon as the sun goes down.
C
Multicell thunderstorms occur when: A) super cells occur along a squall line. B) individual thunderstorms produce multiple vortex tornadoes. C) thunderstorms in various stages of development are clustered together. D) the mesocyclone divides into multiple suction vortices.
C
Of the following states, which is struck by the largest number of tornadoes? A) North Carolina B) Ohio C) Oklahoma D) New Mexico E) North Dakota
C
The gust front occurs: A) during the development of thunderstorm clouds. B) near the anvil part of a thunderstorm cloud. C) at the leading edge of a thunderstorm downdraft. D) on the lee shore of the Great Lakes.
C
Thunderstorms and large cumulonimbus clouds are characteristic of: A) all polar air masses. B) isothermal lapse rates. C) unstable air. D) stable air.
C
Thunderstorms form when ________, humid air rises in a(n) ________ environment. A) warm; stable B) cold; unstable C) warm; unstable or conditionally unstable D) cold; stable
C
Tornadoes are most frequent during the: A) month of September. B) January-March period. C) April-June period. D) October-December period. E) July-August period.
C
Tornadoes most often move toward what direction? A) southeast B) west C) northeast D) southwest E) northwest
C
Which of the following should have the steepest pressure gradient? A) middle-latitude cyclone B) hurricane C) tornado D) typhoon
C
________ are relatively narrow, elongated bands of thunderstorms that develop in the warm sector of a middle-latitude cyclone, usually in advance of a cold front. A) Roll clouds B) Mesocyclones C) Squall lines D) Supercells
C
"Heat lightning": A) is actually a display of the northern lights. B) is also called "ball lightning." C) is brighter than ordinary lightning. D) is regular lightning occurring more than 20 kilometers from the person observing it.
D
1) About how many thunderstorms take place on Earth every day? A) 300 B) 1300 C) 5000 D) 45,000
D
A roll cloud forms in association with which other common thunderstorm feature? A) the precipitation B) the anvil C) the updraft D) the gust front
D
A squall line is most likely to develop where? A) in the middle of a cP air mass B) along a warm front C) along a cold front D) along a dryline in the warm sector of a mid-latitude cyclone
D
An air mass thunderstorm is most intense during the ________ stage. A) multicell B) cumulus C) dissipating D) mature
D
Doppler radar measures: A) raindrop motion. B) raindrop size. C) raindrop and snowflake motion. D) rainfall intensity and motion within the storm. E) cloud droplet numbers.
D
Some of the most dangerous weather is produced by a type of thunderstorm called a(n): A) gust front. B) updraft. C) roll cloud. D) supercell.
D
The terms leader, flash, and stroke are used when describing: A) squall line formation. B) the stages of a thunderstorm. C) the passage of a hurricane. D) lightning. E) a tornado.
D
Thunderstorm tops most likely occur: A) in the lower troposphere. B) in the middle stratosphere. C) in the mesosphere. D) near the tropopause
D
What is the deadliest tornado on record in the United States? A) The Fargo, ND tornado of 1957 B) The Natchez tornado of 1840 C) The Moore, OK tornado of 1999 D) The Tri-State tornado of 1925
D
Which of the following statements best describes multiple-vortex tornadoes? A) A single tornado fades in and out of visibility, giving the illusion of multiple vortices. B) A single funnel cloud divides into two parts about half way to the ground, like the forked tongue of a snake. C) A single thunderstorm produces multiple tornadoes in different areas of the storm. D) Multiple suction vortices circulate around a single tornadic center.
D
Which of the numbers listed below best represents the percentage of thunderstorms that produce tornadoes? A) about 10 percent B) slightly more than 50 percent C) nearly 25 percent D) fewer than 1 percent
D
A tornado is also sometimes known as a: A) Coriolis effect. B) anticyclone. C) jet stream. D) geostrophic wind. E) cyclone.
E
Doppler radars: A) detect lightning strokes. B) have much greater range than conventional radars. C) detect condensation nuclei. D) show the motion of air in clear areas. E) show the motion of precipitation particles
E
If you see lightning and then hear the associated thunder 10 seconds later, the lightning flash was about ________ mile(s) away. A) three B) four C) one D) five E) two
E
Thunderstorms occur year-round in the: A) middle latitudes. B) subtopics. C) polar regions. D) subarctic regions. E) tropics.
E
What causes the dissipating stage of a thunderstorm? A) converging surface winds B) loss of radiant energy from cloud top C) release of latent heat within the cloud D) converging winds aloft E) spreading downdraft cuts off air inflow
E
Why is strong heating of the ground by the Sun associated with thunderstorms? A) reduces the relative humidity B) reduces the dew point C) increases the wind speed D) increases the pressure gradient E) leads to greater instability
E
Why is very humid air near the surface a necessary ingredient for severe thunderstorms? A) High humidity strengthens the cold front. B) High humidity makes the air more dense. C) High humidity makes the rising air cool more rapidly. D) Lapse rates are larger in humid air. E) More latent heat is then available as energy for the storm.
E
) It is generally considered safe to talk on the phone during a lightning storm, as long as it is a corded telephone.(T/F)
False
Cloud-to-ground lightning results in a flow of electrons from the ground to the cloud.(T/F)
False
If a severe thunderstorm produces large hail, it will not produce a tornado.(T/F)
False
Lightning always occurs between a cloud and the ground.(T/F)
False
Lightning only occurs under the central part of a thunderstorm cloud.(t/F)
False
Most precipitation from thunderstorms originates through the collision-coalescence process(t/F)
False
On average, tornadoes kill more people every year in the United States than any other severe weather phenomenon.(T/F)
False
Squall lines are easily recognized because of their unique nimbostratus clouds.(T/F)
False
The primary force causing the fast winds of a tornado is electrical.(T/F)
False
Thunder generates lightning.(T/F)
False
When tornadoes develop it is usually in association with air-mass thunderstorms.(T/F)
False
) Mountainous regions, such as the Rockies in the West and the Appalachians in the East, experience a greater number of air-mass thunderstorms than do the Plains states.(t/f)
True
A developing tornado is called a funnel cloud until it makes contact with the surface.(T/F)
True
A long lightning flash at some distance from the observer produces the thunder we hear as a rumble.(T/F)
True
A mesocyclone often precedes tornado development.(T/F)
True
A squall line with severe thunderstorms can form along a boundary called a dryline, a narrow zone along which there is an abrupt change in moisture.(T/F)
True
An airplane flown by an untrained pilot is likely to crash if it flies through a downburst(t/F)
True
During the dissipating stage of a thunderstorm, the downdraft is stronger than the updraft.(T/F)
True
Large hail is generally associated only with severe thunderstorms(T/F)
True
Temperature inversions (stable layers) in air layers above the ground can enhance thunderstorm development.(T/F)
True
The anvil top of a thunderstorm often marks the beginning of the stratosphere. (t/F)
True
Entrainment refers to the tendency of thunderstorms to form in a line-like pattern or sequence.(t/f)
false
Severe thunderstorm development occurs independently from the air flow aloft.(t/f)
false
