Dbjeas Mc Exam

Front 1

1. Depending on local topography, the maximum range of broadcasts of the NOAA weather radio is about ____________ kilometers.
a. 10
b. 100
c. 20
d. 65

Back 1

d. 65

Front 2

2. Viewed from above in the Northern Hemisphere, surface winds blow ___________ about the center of a low pressure system.
a. clockwise and outward
b. clockwise and inward
c. counterclockwise and outward
d. counterclockwise and inward

Back 2

d. counterclockwise and inward

Front 3

3. Weather systems usually cross the United States in
a. one day.
b. several days.
c. twenty or so days.
d. one month.

Back 3

b. several days

Front 4

4. Weather systems in the mid-latitudes of the Earth generally move in the direction towards the
a. east.
b. south.
c. west.
d. north.

Back 4

a. east

Front 5

5. Air pressure can be thought of as
a. air temperature. b. wind speed.
c. weight of the overlying air.
d. weight of the underlying air.

Back 5

c. weight of the overlying air

Front 6

6 . Weather radar monitors the movement of
a. cloud particles.
b. precipitation.
c. planets
d. river flow

Back 6

b. precipitation

Front 7

7.. Viewed from above in the Northern Hemisphere, surface winds in a high pressure system
blow
a. clockwise and inward.
b. clockwise and outward.
c. counterclockwise and inward.
d. counterclockwise and outward.

Back 7

b. clockwise and outward

Front 8

8.. As a general rule, lows that track from west to east across southern Canada produce
___________ precipitation compared to lows that track along the Gulf of Mexico coast.
a. more
b. a thousand times more
c. less
d. about the same amount of

Back 8

c. less

Front 9

9. Usually, the day’s minimum temperature occurs
a. around sunrise.
b. around midnight.
c. near sunset.
d. at lunch time.

Back 9

a. around sunrise

Front 10

10. Meteorologists use water vapor satellite imagery to
a. determine the humidity in the air next to Earth’s surface.
b. monitor the temperature of the tops of clouds.
c. track the movement of water vapor at higher altitudes of the atmosphere.
d. measure the surface wind speed in a hurricane.

Back 10

c. track the movement of water vapor at higher altitudes of the atmosphere

Front 11

11. A cloud in contact with the Earth’s surface is known as
a. a cumuliform cloud.
b. fog.
c. a cirrus cloud.
d. a thunderstorm.

Back 11

b. fog

Front 12

12 . Wispy-appearing clouds that occur at high altitudes are composed of mostly
a. tiny liquid water droplets.
b. tiny ice crystals.
c. methane.
d. solid carbon dioxide.

Back 12

b. tiny ice crystals

Front 13

1. The saturation vapor mixing ratio of air depends on ____________.
a. relative humidity and temperature
b. vapor mixing ratio and temperature
c. pressure and temperature
d. temperature only
e. vapor mixing ratio and pressure

Back 13

c. pressure and temperature

Front 14

2. As the temperature of a saturated (cloudy) air parcel falls, its relative humidity ______and
the vapor mixing ratio __________.
a. increases, decreases
b. decreases, does not change
c. does not change, decreases
d. does not change, increases
e. increases, increases

Back 14

c. does not change, decreases

Front 15

3. If the temperature and the pressure of an unsaturated (clear) air parcel does not change while
its vapor mixing ratio increases, the density of the parcel ______ and its relative humidity
_______.
a. increases, increases
b. decreases, increases
c. does not change, increases
d. does not change, decreases
e. decreases, does not change

Back 15

b. decreases, increases

Front 16

4 If the vapor mixing ratio of a parcel of air is 2 grams per kilogram and its saturation mixing
ratio is 6 grams per kilogram, the relative humidity is ______ percent.
a. 3
b. 33.3
c. 40
d. 60
e .66.6

Back 16

b. 33.3

Front 17

5. If the mixing ratio of a parcel of air is 6 grams per kilogram and the relative humidity is 25 percent, the saturation mixing ratio is ______ grams per kilogram.
a. 1.5
b. 12
c. 8
d. 2
e. None of these is correct.

Back 17

e. None of these is correct

Front 18

6. If the air temperature is 12 ºC and the vapor mixing ratio is the same as the saturation vapor
mixing ratio, the relative humidity is _________.
a. the relative humidity is less than 100%.
b. the relative humidity is more than 100%.
c. the dewpoint temperature is less than the temperature
d.. the dewpoint temperature is equal to the temperature
e. the dewpoint temperature is more than the temperature

Back 18

d. the dewpoint temperature is equal to the

Front 19

7. On a clear and calm day, the relative humidity usually ______ between sunrise and early
afternoon.
a. rises
b. falls
c. does not change
d. is less than the saturated vapor mixing ratio
e. is less than the vapor mixing ratio

Back 19

b. falls

Front 20

8. As an aircraft ascends within the atmosphere, _________
a. air pressure increases.
b. the vapor mixing ratio increases.
c. the saturation vapor saturation mixing ratio increases.
d. air density increases.
e. None of the above is correct.

Back 20

e. None of the above is correct

Front 21

9.. All of the following soundings (temperature profiles) always indicate stable atmospheric conditions with the exception of
a. temperature inversion.
b. isothermal conditions.
c. no change in temperature with altitude.
d. a drop of temperature with altitude.
e. an increase in temperature with altitude.

Back 21

d. a drop of temperature with altitude

Front 22

10. Conditional instability indicates that an air layer is
a. stable for both saturated and unsaturated air parcels.
b. unstable for saturated and stable for unsaturated air parcels.
c. stable for saturated and unstable for unsaturated air parcels.
d. unstable for both saturated and unsaturated air parcels.
e. None of the above is correct.

Back 22

b. unstable for saturated and stable for unsaturated air parcels

Front 23

11. An Environmental Lapse Rate of ______ Celsius degrees per 1000 meters is stable for
unsaturated air parcels.
a. 6
b. 4
c. 2
d. All of these are correct.
e. None of these is correct.

Back 23

d. All of these are correct

Front 24

12. An Environmental Lapse Rate of ______ Celsius degrees per 1000 meters is unstable for
unsaturated (clear) air parcels.
a. 11
b. 8
c. 1
d. 9
e. None of these is correct.

Back 24

a. 11

Front 25

13. An Environmental Lapse Rate of ______ Celsius degrees per 1000 meters is conditionally unstable.
a. 12
b. 4
c. 8
d. -10
e. 2

Back 25

c. 8

Front 26

14. An Environmental Lapse Rate of ______ Celsius degrees per 1000 meters is stable for clear
air and unstable for cloudy air.
a. 3
b. 7
c. 13
d. 1
e. 11

Back 26

b. 7

Front 27

15. Unstable air _____ vertical motion of air parcels.
a. enhances
b. suppresses
c. has no effect on
d. creates oscillating
e. stops

Back 27

a. enhances

Front 28

16. Rising parcels of saturated (cloudy) air do not cool as rapidly as rising parcels of unsaturated
(clear) air because
a. rising parcels of saturated air do work in expanding.
b. expansional cooling of saturated air is partially compensated for by release of latent heat.
c. saturated air parcels are always warmer than their surroundings.
d. All of the above are correct.
e. None of the above is correct.

Back 28

b. expansional cooling of saturated air is partially compensated for by release of latent heat

Front 29

17. As saturated (cloudy) air flows up the windward slopes of a mountain range,
a. the relative humidity increases.
b. the mixing ratio does not change.
c. the saturation mixing ratio decreases.
d. the air temperature rises.
e. None of these is correct.

Back 29

c. the saturation mixing ratio decreases

Front 30

18. As unsaturated (clear) air flows down the leeward slopes of a mountain range,
a. the air temperature rises.
b. the relative humidity decreases.
c. the saturation vapor pressure increases.
d. All of the above are correct.
e. None of the above is correct.

Back 30

d. All of the above are correct

Front 31

19. As a clear parcel of air ascends dry adiabatically,
a. its relative humidity increases.
b. its saturation vapor mixing ratio decreases.
c. its temperature drops.
d. All of the above are correct.
e. None of the above is correct.

Back 31

d. All of the above are correct

Front 32

20. Suppose the vapor mixing ratio of the cold outside air is the same as the vapor mixing ratio
of the warm air indoors. If the door is opened and the cold air replaces some of the warm air,
then the new relative humidity indoors would be_______
a. higher than before.
b. the same as before.
c. lower than before.
d. 0 %
e. twice it saturation vapor mixing ratio

Back 32

a. higher than before

Front 33

21. Which of these pairs of processes, working together, will make the atmosphere more
unstable?
a. cool the surface and warm the air aloft
b. cool the surface and cool the air aloft
c. warm the surface and cool the air aloft
d. warm the surface and warm the air aloft
e. cool the surface and moisten the air aloft

Back 33

c. warm the surface and cool the air aloft

Front 34

22. A parcel of unsaturated air descends adiabatically without mixing. A descend of 800 m
causes __________.
a. cooling of 8 degrees Celsius
b. warming of 8 degrees Celsius
c. warming of 0.8 degrees Celsius
d. warming of 4 degrees Celsius
e. cooling of 4 degrees Celsius

Back 34

b. warming of 8 degrees Celsius

Front 35

23. 10% relative humidity means that __________.
a. 10% of all molecules are water vapor
b. 10% of the mass of air consists of water vapor
c. 10% of the volume of air is occupied by water vapor
d. 10% of the pressure of the air arises from water vapor
e. none of the above.

Back 35

b. 10% of the mass of air consists of water vapor

Front 36

24. Consider the case of a very calm wind conditions near the ground. An increase in air temperature results in ______________.
a. dewpoint decreases
b. dewpoint increases
c. relative humidity decreases
d. relative humidity increases
e. vapor mixing ratio decreases

Back 36

c. relative humidity decreases

Front 37

25. If an air parcel rises without mixing with ambient air ________________.
a. its volume will decrease
b. its temperature will decrease
c. its density will increase
d. its vapor pressure will decrease
e. its relative humidity will decrease.

Back 37

b. its temperature will decrease

Front 38

1. A cloud that develops as a consequence of local convection is
a. stratus.
b. cirrus.
c. cirrostratus.
d. nimbostratus.
e. cumulus.

Back 38

e. cumulus

Front 39

2. Which one of the following cloud types would most likely be responsible for producing heavy
rain?
a. cumulus
b. cumulonimbus
c. altocumulus
d. cirrocumulus
e. cirrus

Back 39

b. cumulonimbus

Front 40

3. A cloud that exhibits considerable vertical development is
a. fair-weather cumulus.
b. altostratus.
c. stratocumulus.
d. cirrus.
e. cumulonimbus.

Back 40

e. cumulonimbus

Front 41

4.. All of the following clouds typically have relatively low bases with the exception of
a. cirrus.
b. stratus.
c. stratocumulus.
d. fog.
e. nimbostratus.

Back 41

a. cirrus.

Front 42

5. Which one of the following clouds is most likely composed of ice crystals only?
a. stratus
b. cumulonimbus
c. cirrus
d. nimbostratus
e. altocumulus

Back 42

c. cirrus

Front 43

6. Of the following cloud types, which one is coldest?
a. cirrus
b. stratus
c. cumulus
d. altocumulus
e. fog

Back 43

a. cirrus

Front 44

7. Of the following cloud types, which one is warmest?
a. cirrus
b. cirrostratus
c. cirrocumulus
d. altostratus
e. stratus

Back 44

e. stratus

Front 45

8. Which one of the following has the greatest terminal velocity?
a. ice crystal
b. drizzle drop
c. large hailstone
d. raindrop
e. snowflake

Back 45

c. large hailstone

Front 46

9. Most precipitation that falls in midlatitudes originates in ______ clouds.
a. cirrus
b. cumulus
c. nimbostratus or cumulonimbus
d. altostratus
e. stratus

Back 46

c. nimbostratus or cumulonimbus

Front 47

10. It takes about ______ cloud droplets to form a single raindrop.
a. 100
b. 1000
c. 10
d. 100,000
e. 1,000,000

Back 47

e. 1,000,000

Front 48

11. A warm cloud is composed of
a. tiny water droplets.
b. ice crystals.
c. a mixture of ice crystals and supercooled water droplets.
d. supercooled water droplets.
e. None of the above is correct.

Back 48

a. tiny water droplets

Front 49

12. The type of frozen precipitation sometimes produced by a summer thunderstorm is
a. snow.
b. freezing rain.
c. snow pellets.
d. hail.
e. sleet.

Back 49

d. hail

Front 50

13. On average, the meltwater equivalent of 100 cm of fresh snowfall is ______ cm.
a. 1
b. 10
c. 100
d. . 20
e. 0.1

Back 50

b. 10

Front 51

1. In equal volumes, which one of the following air masses has the highest air density?
a. cP
b. A
c. mP
d. cT
e. mT

Back 51

b. A

Front 52

3. A source region for maritime tropical air is
a. northern Canada.
b. the American Southwest.
c. the Gulf of Mexico.
d. the North Atlantic.
e. None of these is correct.

Back 52

c. the Gulf of Mexico

Front 53

4. Warm and humid air:
a. A
b. mP
c. mT
d. cP
e. cT

Back 53

c. mT

Front 54

5. Of the following air masses, which one exhibits the greatest temperature change between
winter and summer?
a. maritime tropical
b. continental polar
c. maritime polar
d. equatorial

Back 54

b. continental polar

Front 55

6. Usually air mass modification is most rapid when
a. continental polar air moves over a frozen lake.
b. continental polar air travels over a snow-covered ground.
c. continental polar air moves over bare ground.
d. maritime tropical air moves over bare ground.

Back 55

c. continental polar air moves over bare ground

Front 56

7. As a warm front approaches, clouds appear in which of the following sequences?
a. cirrus, altostratus, stratus
b. stratus, altostratus, cirrus
c. cumulus, cumulonimbus, cirrus
d. cumulonimbus, cumulus, nimbostratus
e. nimbostratus, cirrocumulus, cirrus

Back 56

a. cirrus, altostratus, stratus

Front 57

8. The cloud and precipitation shield associated with a cold front typically is ______ the cloud
and precipitation shield associated with a warm front.
a. wider than
b. narrower than
c. the same width as
d. weaker than

Back 57

b. narrower than

Front 58

9. A front is a narrow zone of transition between air masses that contrast in
a. temperature.
b. vapor mixing ratio.
c. air density.
d. Any of these is correct.
e. None of these is correct.

Back 58

d. Any of these is correct

Front 59

10. A type of cloud associated with a fast-moving, well-defined cold front:
a. cirrus
b. stratus
c. cumulonimbus
d. cirrostratus
e. None of these is correct.

Back 59

c. cumulonimbus

Front 60

The type of front formed when the leading edge of cold air merges with a warm front is
known as
a. a cold front.
b. a warm front.
c. a stationary front.
*d. an occluded front.
e. None of these is correct.

Back 60

d. an occluded front

Front 61

1. If the surface wind backs from northeast to north, Halifax (Nova Scotia) usually experiences

a. cold air advection.
b. warm air advection.
c. snow changing to rain.
d. falling air pressure.
e. hail

Back 61

a. cold air advection

Front 62

2. If the surface wind veers from east to southeast to south, Halifax (Nova Scotia usually
experiences

a. cold air advection.
b. warm air advection.
c. rain changing to snow.
d. rising air pressure.
e. falling tempera¬tures.

Back 62

b. warm air advection

Front 63

3. In a mature extratropical cyclone, fog and drizzle are most likely to develop

a. to the northwest of the low center.
b. in the warm air behind the warm front.
c. in the cold air just ahead of the surface warm front.
d. in the warm air just ahead of the surface cold front.
e. None of the above is correct.

Back 63

c. in the cold air just ahead of the surface warm front

Front 64

4 . If a weather station reports a wind shift from northeast to north and then northwest and a
steady rain turning to snow flurries, the low center is most likely moving

a. from west to east, north of the station.
b. from northeast to southwest, north of the station.
c. from southwest to northeast, east of the station.
d. from southwest to northeast, north of the station.
e. None of the above is correct.

Back 64

c. from southwest to northeast, east of the station

Front 65

5. . Precipitation tends to be steady and persistent in the ______ sector of a mature extratropical
cyclone.

a. northeast
b. northwest
c. southeast
d. southwest

Back 65

a. northeast

Front 66

5. . Precipitation tends to be steady and persistent in the ______ sector of a mature extratropical
cyclone.

a. northeast
b. northwest
c. southeast
d. southwest

Back 66

a. northeast

Front 67

7. The warmest sector of a mature extratropical cyclone is usually __________ of the cyclone
center.

a. northeast
b. northwest
c. southeast
d. southwest

Back 67

c. southeast

Front 68

8. The warmest air associated with a mature extratropical cyclone is usually located

a. at the low center.
b. southwest of the low center.
c. northwest of the low center.
d. southeast of the low center.
e. None of the above is correct.

Back 68

d. southeast of the low center

Front 69

9. What is the surface wind direction in the northwest sector of a mature extratropical cyclone?

a. southeast
b. east
c. south
d. northwest
e. southwest

Back 69

d. northwest

Front 70

9. What is the surface wind direction in the northwest sector of a mature extratropical cyclone?

a. southeast
b. east
c. south
d. northwest
e. southwest

Back 70

d. northwest

Front 71

10. Viewed from above, the surface wind circulation about an Alberta-type cyclone is

a. clockwise and outward.
b. clockwise and inward.
c. counterclockwise and outward.
d. counterclockwise and inward.
e. None of the above is correct.

Back 71

d. counterclockwise and inward

Front 72

1. A thunderstorm cloud:
a. cumulus
b. nimbostratus
c. cumulonimbus
d. stratus
e. altostratus

Back 72

c. cumulonimbus

Front 73

2. The mature stage of the life cycle of a thunderstorm cell is characterized by
a. updrafts only.
b. both updrafts and downdrafts.
c. cloud dissipation.
d. downdrafts only.
e. no updrafts and no downdrafts

Back 73

b. both updrafts and downdrafts

Front 74

3.. The anvil top of a thunderstorm cloud is likely to be a ______ cloud that is composed of
______.
a. warm................supercooled water droplets
b. cold...............liquid water droplets
c. cirrus...............ice crystals
d. altocumulus...............water droplets
e. stratus...............drizzle

Back 74

c. cirrus...............ice crystals

Front 75

4.. A gust front is associated with a(n)
a. intense thunderstorm.
b. land breeze.
c. chinook wind.
d. sea breeze.
e. None of these is correct

Back 75

a. intense thunderstorm

Front 76

5. Appearance of a flat anvil top indicates that the developing thunderstorm cloud
(cumulonimbus) has reached a(n) ______ portion of the atmosphere.
a. unstable
b. neutral
c. conditionally stable
d. humid
e. extremely stable

Back 76

e. extremely stable

Front 77

6. The dissipating stage of the life cycle of a thunderstorm cell is characterized by
a. updrafts only.
b. both updrafts and downdrafts.
c. hail and heavy rain.
d. the strongest surface winds.
e. downdrafts only.

Back 77

e. downdrafts only

Front 78

7.. A mesoscale convective complex (MCC)
a. is the same as a supercell thunderstorm.
b. consists of numerous interacting thunderstorm cells.
c. is usually located just ahead of a fast-moving, well-defined cold front.
d. has a life expectancy of less than an hour.
e. is most likely to occur in the Pacific Northwest.

Back 78

b. consists of numerous interacting thunderstorm cells

Front 79

8. A squall line usually forms
a. along a stationary front.
b. in the cold air mass well behind a cold front.
c. in the mT air along or ahead of a cold front.
d. in the fog and cold air mass just north of a warm front.
e. None of these is correct.

Back 79

c. in the mT air along or ahead of a cold front

Front 80

9. Thunderstorm development is favored
a. by stable air.
b. over relatively cold surfaces.
c. by free convection alone.
d. by conditionally unstable maritime tropical air.
e. in arctic air

Back 80

d. by conditionally unstable maritime tropical air

Front 81

10. Thunderstorm cells associated with a fast-moving, well-defined cold front
a. may be severe.
b. often occur as a squall line parallel to and ahead of the front.
c. often form an elongated cluster parallel to the front.
d. All of the above are correct.
e. None of the above is correct.

Back 81

d. All of the above are correct

Front 82

11. Thunderstorm development is triggered by
a. uplift along a well-defined cold front.
b. converging surface winds.
c. uplift of warm, humid air along mountain slopes.
d. forced convection.
e. Any of the above is correct.

Back 82

e. Any of the above is correct

Front 83

12. A feature sometimes present in thunderstorms that may prolong the mature stage is (are) _____.
a. abundant ice nuclei at high altitudes.
b. an anvil top.
c. a cold downdraft.
d. precipitation.
e. a tilted updraft.

Back 83

e. a tilted updraft

Front 84

13. A supercell thunderstorm is most likely to develop in the ______ sector of a mature extra-
tropical cyclone.
a. northwest
b. southeast
c. northeast
d. southwest
e. cold

Back 84

b. southeast

Front 85

14. A severe thunderstorm cell may be accompanied by__________.
a. damaging surface winds.
b. hail.
c. heavy rainfall.
d. frequent lightning.
e. Any of these is correct.

Back 85

e. Any of these is correct

Front 86

15. A dry line ______.
a. is a likely site for development of a severe thunderstorm cell.
b. separates hot, dry air from warm, humid air.
c. often occurs over Texas and Oklahoma.
d. All of the above are correct.
e. None of the above is correct.

Back 86

d. All of the above are correct

Front 87

1. A thunderstorm cloud is a __________.
a. cumulus
b. nimbostratus
c. cumulonimbus
d. stratus
e. altostratus

Back 87

c. cumulonimbus

Front 88

2. On a clear day, the Earth's surface carries ______ electrical charge.
a. a positive
b. no
c. a negative
d. a double
e. a triple

Back 88

c. a negative

Front 89

3. Lightning occurs________.
a. only when it is raining.
b. only during the towering cumulus stage of a thunderstorm life cycle.
c. most often in Michigan.
d. All of the above are correct.
e. None of the above is correct.

Back 89

e. None of the above is correct

Front 90

4. Thunder is the consequence of ________.
a. a tilted updraft.
b. hail formation.
c. clouds bumping into one another.
d. lightning.
e. the gust front.

Back 90

d. lightning

Front 91

5. Sound waves are considerably ______ than light waves so that thunder is heard ______
lightning is seen.
a. slower...............before
b. slower...............after
c. faster...............before
d. faster..............after

Back 91

b. slower...............after

Front 92

1. A downburst _______.
a. is most likely to occur during the towering cumulus stage of a thunderstorm life cycle.
b. is never accompanied by virga.
c. is designated a microburst or macroburst depending on the distance impacted along the ground.
d. All of the above are correct.
e. None of the above is correct.

Back 92

c. is designated a microburst or macroburst depending on the distance impacted along the ground

Front 93

2. Microbursts are particularly dangerous for aircraft on takeoff or landing because they trigger ______.
a. lightning.
b. visibility-restricting rain.
c. large hailstones.
d. wind shear.
e. roll clouds.

Back 93

d. wind shear

Front 94

3. A flash flood is most likely to be triggered by heavy rains that develop in a precipitation
efficient atmosphere, that is, an atmosphere that features _________.
a. high values of precipitable water
b. high relative humidity
c. a warm thunderstorm base
d. All of the above are correct.
e. None of the above is correct.

Back 94

d. All of the above are correct

Front 95

4. Hail is typically produced by thunderstorm cells that are characterized by __________.
a. strong updrafts.
b. great vertical development.
c. an abundant supply of supercooled water droplets.
d. All of the above are correct.
e. None of the above is correct.

Back 95

d. All of the above are correct

Front 96

1. The most important force operating in a tornado is (the) ____.
a. pressure gradient force.
b. Coriolis effect.
c. gravity.
d. friction.
e. None of these is correct.

Back 96

a. pressure gradient force

Front 97

2. The Coriolis deflection is negligible in a tornado because _____.
a. tornadoes originate over the equator.
b. the system is too small to be significantly affected by the Earth's rotation.
c. of surface roughness.
d. All of the above are correct.
e. None of the above is correct.

Back 97

b. the system is too small to be significantly affected by the Earth's rotation

Front 98

3. A characteristic of most tornadoes in the Northern Hemisphere is
a. counterclockwise rotation as viewed from above.
b. a track toward the east or northeast.
c. association with a severe thunderstorm cell.
d. All of the above are correct.
e. None of the above is correct.

Back 98

d. All of the above are correct

Front 99

4. A tornadic circulation that remains aloft and does not touch the Earth's
surface is known as a ________
a. dust devil.
b. waterspout.
c. funnel cloud.
d. hurricane
e. typhoon

Back 99

c. funnel cloud

Front 100

5. If you are indoors when a tornado approaches, the best precaution is to
a. lie down against an exposed wall.
b. stand near a window to see where the tornado is going.
c. go to the basement and get under a sturdy bench.
d. go to bed and pull the covers over your head.
e. make sure all the windows are open.

Back 100

c. go to the basement and get under a sturdy bench

Front 101

6. Typically, of all the tornadoes that occur each year in North America,
most are rated as ______ on the F-scale.
a. weak
b. strong
c. violent

Back 101

a. weak

Front 102

7. The most intense tornadoes are rated ______ on the F-scale.
a. 0
b. 1
c. 5
d. 2

Back 102

c. 5

Front 103

8. Tornadoes are most likely to develop
a. along the California coast.
b. in the Rocky Mountain states.
c. in the Appalachian mountains.
d. in Illinois during winter.
e. in Oklahoma during spring.

Back 103

e. in Oklahoma during spring

Front 104

9. Tornadoes are most likely to occur in the ______ sector of an intense
extratropical cyclone.
a. northeast
b. southeast
c. southwest
d. northwest

Back 104

b. southeast

Front 105

10. In the United States, tornadoes are most often triggered by
a. cyclones.
b. hurricanes.
c. seasonal shifts of the ITCZ.
d. lightning.
e. anticyclones.

Back 105

a. cyclones

Front 106

11. In the southern Great Plains, tornadoes are most likely to develop when
a. dry Pacific air overlies a layer of maritime tropical air.
b. maritime tropical air overlies a layer of dry Pacific air.
c. maritime tropical air extends from the ground to the altitude of the polar front jet stream
d. the region is dominated by high pressure.
e. None of the above is correct.

Back 106

a. dry Pacific air overlies a layer of maritime tropical air

Front 107

12. Condition needed for the development of a tornadic circulation within a
thunderstorm:
a. strong updraft.
b. strong vertical shear in the horizontal wind.
c. development of a mesocyclone.
d. All of the above are correct.
e. None of the above is correct.

Back 107

d. All of the above are correct

Front 108

13. A weak tornado has a life expectancy of
a. several hours.
b. a few days.
c. a week or two.
d. 1 to 3 minutes.

Back 108

d. 1 to 3 minutes

Front 109

14. The Coriolis effect is more important in a ______ than in a(n) ______.
a. thunderstorm...............tornado
b. tornado...............cyclone
c. tornado...............anticyclone
d. weak thunderstorm...............supercell
e. weak thunderstorm..............mesocyclone

Back 109

a. thunderstorm...............tornado

Front 110

15. In the United States, the months of peak tornado activity are
a. January, February, and March.
b. March, April, and May.
c. April, May, and June.
d. May, June, and July.
e. June, July, and August.

Back 110

c. April, May, and June

Front 111

16. A weak tornado is rated ______ on the F-scale.
a. 0 or 1
b. 2 or 3
c. 4 or 5
d. 6 or 7
e. 8 or 9

Back 111

a. 0 or 1

Front 112

1. Historically, the most destructive aspect of a hurricane striking a low-lying coastal area is
a. strong winds.
b. heavy rains.
c. hail.
d. wind shear.
e. storm surge.

Back 112

e. storm surge

Front 113

2. A hurricane differs from an extratropical cyclone in that a hurricane
a. has no fronts.
b. develops within a uniform warm and humid air mass.
c. is more intense but smaller.
d. is a warm-core system.
e. All of the above are correct.

Back 113

e. All of the above are correct

Front 114

3. Sustained surface winds in a hurricane are
a. greater than 250 km (155 mi) per hour.
b. 119 km (74 mi) per hour or higher.
c. strongest in the eye of the system.
d. typically stronger than the winds produced by a F5 tornado.
e. weakest along the eye wall.

Back 114

b. 119 km (74 mi) per hour or higher

Front 115

4.. Typical weather within the eye of a hurricane consists of
a. large hail.
b. strong winds but clear skies.
c. fair skies and light winds.
d. thunder and lightning.
e. tornadoes.

Back 115

c. fair skies and light winds

Front 116

5. Hurricanes do not typically form at latitudes north of 30 degrees N because
a. the surface ocean water is too cold.
b. there is no Coriolis effect.
c. the air is too warm.
d. All of the above are correct.
e. None of the above is correct.

Back 116

a. the surface ocean water is too cold

Front 117

6. Hurricanes do not form at the equator because
a. sea-surface temperatures typically are too low.
b. there is no Coriolis effect.
c. fronts are present.
d All of the above are correct.
e. None of the above is correct.

Back 117

b. there is no Coriolis effect

Front 118

7. The source of energy that sustains a hurricane circulation is
a. sensible heat.
b. latent heat.
c. infrared radiation.
d. ultraviolet radiation.
e. None of these is correct.

Back 118

b. latent heat

Front 119

8. Most Northern Hemisphere hurricanes occur
a. in winter.
b. from June through November.
c. from November through March.
d. in spring.
e. in early summer.

Back 119

b. from June through November

Front 120

9. At latitude 10 degrees N, Atlantic basin hurricanes generally
a. drift slowly toward the east.
b. drift slowly toward the west.
c. move rapidly toward the northeast.
d. move rapidly southward.
e. stay there for two months

Back 120

b. drift slowly toward the west

Front 121

10. At latitude 10 degrees N, tropical cyclones are steered by the
a. westerlies.
b. northeast trade winds.
c. southeast trade winds.
d. polar easterlies.
e. circumpolar vortex.

Back 121

b. northeast trade winds

Front 122

11. The central pressure is ______ in a hurricane than in a typical extratropical cyclone.
a. higher
b. lower
c. about the same

Back 122

b. lower

Front 123

12. The eye of a hurricane typically
a. shrinks in diameter as the hurricane intensifies.
b. features subsiding air.
c. is surrounded by a ring of cumulonimbus clouds (the eye wall).
d. All of the above are correct.
e. None of the above is correct.

Back 123

d. All of the above are correct

Front 124

13. Hurricane formation requires a sea-surface temperature of at least ______ ºC through a depth
of about 60 meters.
a. 15.0
b. 20.5
c. 26.5
d. 31.5
e. 34.5

Back 124

c. 26.5

Front 125

14. Ultimately, the rate of evaporation of seawater is governed principally by
a. air pressure.
b. cloud cover.
c. sea-surface temperature.
d. whether it is raining or snowing.
e. the tides.

Back 125

c. sea-surface temperature

Front 126

15. Force(s) operating within a hurricane:
a. Coriolis effect
b. friction
c. pressure gradient force
d. centripetal force
e. All of the above are correct.

Back 126

e. All of the above are correct

Front 127

16. The minimum latitude where the Coriolis effect is strong enough to sustain a hurricane
circulation is about ______ degrees.
a. 0
b. 4
c. 10
d. 20
e. 23.5

Back 127

b. 4

Front 128

17. Hurricanes and tropical storms never threaten
a. New England.
b. North Carolina.
c. the west coast of South America.
d. coastal California.
e. New Jersey.

Back 128

c. the west coast of South America

Front 129

18. A hurricane breeding ground:
a. the Indian Ocean east of Madagascar
b. the Arabian Sea
c. the Bay of Bengal
d. the Gulf of Mexico
e. All of the above are correct.

Back 129

e. All of the above are correct

Front 130

19. Hurricanes are absent off the coast of South America primarily because of
a. shear produced by strong winds in the middle and upper troposphere.
b. a weak Coriolis effect.
c. persistent cloud-cover.
d. relatively low sea-surface temperatures.
e. None of the above is correct.

Back 130

a. shear produced by strong winds in the middle and upper troposphere

Front 131

20. Most hurricane-related fatalities are caused by
a. associated tornadoes.
b. strong surface winds.
c. lightning.
d. coastal and inland flooding.
e. spin-up vortices.

Back 131

d. coastal and inland flooding

Front 132

21. Hurricane winds
a. weaken rapidly once the system makes landfall.
b. typically cause extensive property damage thousands of kilometers inland.
c. are usually stronger than the winds in a violent tornado.
d. strengthen as the system moves from over the ocean to over land.
e. None of the above is correct

Back 132

a. weaken rapidly once the system makes landfall

Front 133

22. As a hurricane tracks from sea to land,
a. surface winds weaken and shift toward the eye.
b. surface winds weaken and rains end abruptly.
c. the threat of tornadoes ends.
d. surface winds shift toward high pressure.
e. None of the above is correct.

Back 133

a. surface winds weaken and shift toward the eye

Front 134

23. As a hurricane tracks inland, its
a. winds diminish.
b. central pressure rises.
c. rains continue.
d. horizontal pressure gradient weakens.
e. All of the above are correct.

Back 134

e. All of the above are correct

Front 135

24. The heavy rains of a hurricane
a. are almost always confined to coastal areas.
b. are triggered by subsidence within the eye.
c. often continue as the system tracks well inland.
d. seldom produce flooding.
e. None of the above is correct.

Back 135

c. often continue as the system tracks well inland

Front 136

25. By convention, major hurricanes rate ______ or higher on the Saffir-Simpson Hurricane
Intensity Scale.
a. 1
b. 2
c. 3
d. 4
e. 5

Back 136

c. 3

Front 137

26. The first sign that a hurricane may be developing over tropical seas is the appearance of
a. high, thin cirrus clouds.
b. a warm anticyclone.
c. strong winds aloft.
d. altocumulus lenticularis clouds.
e. an organized cluster of cumulonimbus clouds.

Back 137

e. an organized cluster of cumulonimbus clouds

Front 138

27. A tropical disturbance may be triggered by
a. the intertropical convergence zone (ITCZ).
b. a trough in the westerlies intruding into low latitudes.
c. an easterly wave.
d. Any of the above is correct.
e. None of the above is correct.

Back 138

d. Any of the above is correct

Front 139

28. The following condition(s) would inhibit development of tropical storms and hurricanes
over the tropical eastern Atlantic:
a. subsidence of air on the eastern flank of the Bermuda-Azores high
b. strong vertical wind shear
c. low vapor pressure in the middle troposphere
d. unusually low sea-surface temperatures
e. Any of the above is correct.

Back 139

e. Any of the above is correct

Front 140

29. When a hurricane threatens low-lying coastal areas, the most prudent strategy for residents is
to
a. seek shelter in the basement.
b. purchase flood insurance and wait out the storm at home.
c. hide under a sturdy table or bench.
d. evacuate to an inland shelter.
e. ride out the storm on a boat.

Back 140

d. evacuate to an inland shelter

Front 141

30. The hurricane threat to the Southeast United States is serious because
a. most residents have never experienced a hurricane.
b. of rapid population growth in coastal areas.
c. of the vulnerability of low-lying coastal areas to a storm surge.
d. All of the above are correct.
e. None of the above is correct.

Back 141

d. All of the above are correct

Front 142

31. The most hurricane-prone location in the United States is
a. New England.
b. Florida.
c. Chicago, IL.
d. San Diego, CA.
e. Tucson, AZ.

Back 142

b. Florida

Front 143

32. The major source of energy in a hurricane is the
a. downdraft in the system’s "eye."
b. polar front jet stream aloft.
c. strong temperature contrast across fronts.
d. release of the latent heat of vaporization.
e. None of the above is correct.

Back 143

d. release of the latent heat of vaporization

Front 144

33. The highest wind speeds in a hurricane occur
a. between spiral bands.
b. in the spiral cloud bands.
c. in the eye wall.
d. in the eye.
e. at the tropopause

Back 144

c. in the eye wall

Front 145

34. Hurricanes dissipate when
a. they move over colder ocean water.
b. they move over land.
c. surface inflow of air exceeds upper-level outflow of air.
d. All of the above are correct.
e. None of the above is correct.

Back 145

d. All of the above are correct

Front 146

35. A(n) __________ is often situated above a hurricane.
a. polar jet stream
b. subpolar low
c. ITCZ
d. anticyclonic air flow
e. None of the above is correct.

Back 146

d. anticyclonic air flow

Front 147

36. A tropical storm or hurricane develops in __________ air.
a. continental tropical
b. continental polar
c. arctic
d. maritime polar
e. maritime tropical

Back 147

e. maritime tropical

Front 148

37. Overall, category 5 hurricanes are __________category 2 and 3 hurricanes.
a. less destructive than
b. much more common than
c. more frequent than
d. much less frequent than

Back 148

d. much less frequent than

Front 149

38. A hurricane is approaching you from the east. The wind changes from very strong northerly
to calm. This means that
a. the eye is overhead and it is safe to come out.
b. the eye is overhead and the other half of the system is yet to come.
c. the hurricane has dissipated and only light showers remain.
d. a tornado spawned by the hurricane just missed you.

Back 149

b. the eye is overhead and the other half of the system is yet to come

Front 150

39. In the United States over the 30-year period from 1970 to 1999, the majority of deaths due to
tropical storms or their remnants was due to
a. tornadoes.
b. lightning.
c. storm surge flooding.
d. inland freshwater flooding.
e. high winds.

Back 150

d. inland freshwater flooding

Front 151

40. Which one of the following statements is true?
a. Easterly waves originate in North Africa.
b. Easterly waves typically travel from west to east across the tropical Pacific.
c. Hurricanes occasionally develop off the coast of Norway.
d. A barrier island is an ideal location for a hurricane shelter.
e. A hurricane is the only type of coastal storm that can produce a storm surge.

Back 151

a. Easterly waves originate in North Africa

Front 152

1. A typical scenario giving rise to blizzards in the Keewatin area of Nunavut (e.g. Baker Lake) is a high
centred over _____ and a low centred over _____.
a. Beaufort Sea, Hudson’s Bay
b. Beaufort Sea, Great Lakes
c. Hudson’s Bay, Beaufort Sea
d. Hudson’s Bay, Gulf of Alaska
e. Greenland, Ellesmere Island

Back 152

b. Beaufort Sea, Great Lakes

Front 153

2. In a mature extra-tropical cyclone, drizzle is most likely to develop
a. to the northwest of the low center.
b. in the warm air behind the warm front.
c. in the cold air just ahead of the surface warm front.
d. in the warm air just ahead of the surface cold front.
e. right at the centre of lowest surface pressure. .

Back 153

c. in the cold air just ahead of the surface warm front

Front 154

3. If at Edmonton airport the weather station reports a wind shift from northeast to north and then
northwest and a steady rain turning to snow flurries, the low center is most likely moving
a. from west to east, north of Edmonton.
b. from northeast to southwest, north of Edmonton.
c. from southwest to northeast, east of Edmonton.
d. from southwest to northeast, north of Edmonton.
e. None of the above is correct.

Back 154

c. from southwest to northeast, east of Edmonton

Front 155

4. Precipitation tends to be steady and persistent in the ______ sector of a mature extra-tropical cyclone.
a. northeast
b. northwest
c. southeast
d. southwest
e. dry

Back 155

a. northeast

Front 156

5.. A cyclonic bomb is defined as an extra-tropical cyclone whose central pressure drops by at least
a. 100 mb in 24 hours
b. 24 mb in 24hours
c. 10 mb in 24 hours
d. 24 mb in 6 hours
e. 10 mb in 6 hours

Back 156

b. 24 mb in 24hours

Front 157

13. The mature stage of the life cycle of a thunderstorm cell is characterized by
a. updrafts only.
b. both updrafts and downdrafts.
c. cloud dissipation.
d. downdrafts only.
e. no vertical air motion

Back 157

b. both updrafts and downdrafts

Front 158

14. The dissipating stage of the life cycle of a thunderstorm cell is characterized by
a. updrafts only.
b. both updrafts and downdrafts.
c. hail and heavy rain.
d. the strongest surface winds.
e. downdrafts only.

Back 158

e. downdrafts only

Front 159

15. Thunderstorm development is favored
a. by stable air.
b. over relatively cold surfaces.
c. by free convection alone.
d. by conditionally unstable maritime tropical air.
e. in arctic air.

Back 159

d. by conditionally unstable maritime tropical air

Front 160

16 . Which is the most important factor in distinguishing a single cell, multi-cell cluster and supercell
thunderstorms?
a. instability
b. cloud base level
c. cloud top height
d. wind shear
e. cooling aloft.

Back 160

d. wind shear

Front 161

17.. The four “ingredients” needed for forming severe organized thunderstorms are:
a. large convective instability, ample humidity, strong wind shear, no trigger to release
instability
b. large convective instability, ample humidity, strong wind shear, trigger to
release instability
c. no convective instability, ample humidity, strong wind shear, trigger to release
instability
d. large convective instability, no humidity, strong wind shear, trigger to release
instability
e. large convective instability, ample humidity, no wind shear, trigger to release
instability

Back 161

b. large convective instability, ample humidity, strong wind shear, trigger to
release instability

Front 162

18. A multicell (or multicelluar) thunderstorm consists of _______.
a several cells, each of which is turning clockwise
b. two cells, one turning clockwise and one turning counter clockwise
c. several cells, each of which moving in a similar direction
d. several cells, each of which moving in a different direction than its neighboring cell
e. several cells, each of which moving in the direction opposite to the storm motion.
3

Back 162

c. several cells, each of which moving in a similar direction

Front 163

19. A squall line is ____________.
a. a random cluster of cells none of which moves
b. a random cluster of cells all of which turn counter clockwise
c. an elongated cluster of cells that is accompanied by a gustfront at the line’s leading edge.
d. an elongated cluster of cells that is accompanied by a calm winds at the line’s leading edge.
e. an elongated cluster of cells that is accompanied by fog at the line’s leading edge.

Back 163

c. an elongated cluster of cells that is accompanied by a gustfront at the line’s leading edge

Front 164

20. Thunderstorm cells associated with a fast-moving, well-defined cold front
a. may be severe.
b. often occur as a squall line parallel to and ahead of the front.
c. often form an elongated cluster parallel to the front.
d. All of the above are correct.
e. None of the above is correct.

Back 164

d. All of the above are correct

Front 165

21. The anvil top of a thunderstorm cloud is likely to be a ______ cloud that is composed of ______.
a. warm................supercooled water droplets
b. cold...............liquid water droplets
c. cirrus...............ice crystals
d. altocumulus...............water droplets
e. stratus...............drizzle

Back 165

c. cirrus...............ice crystals

Front 166

22. A squall line usually forms
a. along a stationary front.
b. in the cold air mass well behind a cold front.
c. in the mT air along or ahead of a cold front.
d. in the fog and cold air mass just north of a warm front.
e. None of these is correct.

Back 166

c. in the mT air along or ahead of a cold front

Front 167

23. A severe thunderstorm cell may be accompanied by
a. damaging surface winds.
b. hail.
c. heavy rainfall.
d. frequent lightning.
e. Any of these is correct.

Back 167

e. Any of these is correct

Front 168

24. A dry line
a. is a likely site for development of a severe thunderstorm cell.
b. separates hot, dry air from warm, humid air.
c. often occurs over Texas and Oklahoma.
d. All of the above are correct.
e. None of the above is correct.

Back 168

d. All of the above are correct

Front 169

25. The leading edge of a thunderstorm ‘s cold downdraft is kmown as a ______.
a. gust front
b. downburst
c. squall line
d. dry line
e. microburst

Back 169

a. gust front

Front 170

26. Squall lines generally do not form:
a. behind a cold front.
b. when the air aloft develops waves downwind from a cold front.
c. along adry line.
d. in the warm sector where warm dry air meets warm, humid air.
e. ahead of an advacing cold front.

Back 170

a. behind a cold front

Front 171

27. Lightning occurs
a. only when it is raining at the ground.
b. only during the cumulus stage of the thunderstorm life cycle.
c. most often in the early morning hours.
d. most often during winter.
e. None of the above is correct.

Back 171

e. None of the above is correct

Front 172

28. Sound waves are ______ than light waves so that thunder is heard ______ lightning is seen.
a. slower, before
b. slower, exactly when
c. slower, after
d. faster, before
e. faster, after

Back 172

c. slower, after

Front 173

29. Which of the following statements is false?
a. Indonesia experiences more than 150 thunderstorm days per year.
b. The highest thunderstorm frequency in the USA occurs in Florida.
c. The inhabited place with the lowest thunderstorm frequency is India, Asia.
d. At any given time, there are about 2000 thunderstorms underway around the world.
e. The highest thunderstorm frequency in Canada occurs in southwestern Ontario.

Back 173

c. The inhabited place with the lowest thunderstorm frequency is India, Asia

Front 174

30 On a clear day, I climb from the bottom to the top of the Tory building (height about 50 m) and
measure the increase in the atmospheric electric potential. I would expect to measure an increase of about:
a. 50 V
b. 5,000 V
c. 300 V
d. 30,000 V
e. 120 V

Back 174

b. 5,000 V

Front 175

31. The principal non-inductive thunderstorm charging mechanism near cloud base involves collisions
between rebounding ice crystals and riming graupel particles. The main result is that at temperatures _____
about -15°C, the graupel particle acquires a _____ charge and the ice crystal acquires a _____ charge.
a. below, negative, positive
b. below, positive, negative
c. above, positive, negative
d. above, negative, positive
e. above, negative, negative

Back 175

c. above, positive, negative

Front 176

32. Which of the following best represents the sequence of events in a typical cloud-to-ground lightning
stroke?
a. upward streamer, dart leader, return stroke, stepped leader, continuing current
b. stepped leader, return stroke, upward streamer, dart leader, continuing current
c. dart leader, upward streamer, return stroke, stepped leader, continuing current
d. stepped leader, upward streamer, return stroke, dart leader, continuing current
e. stepped leader, upward streamer, dart leader, return stroke, continuing current

Back 176

d. stepped leader, upward streamer, return stroke, dart leader, continuing current

Front 177

33. I estimate that the time between the lightning flash and the beginning of thunder was 0.5 seconds. How
far away was the strike point?
a. 50 m
b. 150 m
c. 500 m
d. 1.5 km
e 3 km

Back 177

b. 150 m

Front 178

34. The negative charge in a thunderstorm is centred around:
a. 0°C
b. -5°C
c. -10°C
d. -15°C
e. -20°C

Back 178

d. -15°C

Front 179

35. The electrical resistance of the atmosphere is approximately:
a. 1 Ohm
b. 200 Ohms
c. 3,000 Ohms
d. 300,000 Ohms
e. 1,000,000 Ohms

Back 179

b. 200 Ohms

Front 180

36. A single flash typically consist of several __, each preceded by a ___ and separated by about _______.
a. stepped leaders, corona discharge, 50 milliseconds
b. dart leaders, upward streamer, 1 second
c. return strokes, dart leader, 50 milliseconds
d. dart leaders., return stroke, 50 microseconds
e. stepped leaders, return stroke, 50 microseconds

Back 180

c. return strokes, dart leader, 50 milliseconds

Front 181

37. Which of the following is not recommended lightning safety procedure?
a. Do not use the telephone.
b. Get inside an all-metal car.
c. Do not stand under a tall tree.
d. Get off open water .
e. Ground yourself by holding on to a metal pole.
6

Back 181

e. Ground yourself by holding on to a metal pole

Front 182

38. A thunderstorm lasts for 3 hours and gives rise to 10,000 lightning strokes, each of which transfers 10
Coulombs of charge to the ground. What is the average current between the storm and the ground?
a. 1 Amperes
b. 10 Amperes
c. 100 Amperes
d. 1,000 Amperes
e. 10,000 Amperes

Back 182

b. 10 Amperes

Front 183

39. The downburst feature of a thunderstorm is mostly caused by
a. cold air resulting from evaporation
b. cold air sinking from the anvil cloud
c. convergence of upper winds
d. melting of snow in the cloud
e. latent heat released in the cloud .

Back 183

a. cold air resulting from evaporation

Front 184

40. Microbursts are particularly dangerous for aircraft on takeoff or landing because they trigger
a. lightning.
b. visibility-restricting rain.
c. large hailstones.
d. wind shear.
e. roll clouds.

Back 184

d. wind shear

Front 185

41. Hail is typically produced by thunderstorm cells that are characterized by
a. strong updrafts.
b. great vertical development.
c. an abundant supply of supercooled water droplets.
d. All of the above are correct.
e. None of the above is correct.

Back 185

d. All of the above are correct

Front 186

42. A derecho is:
a. Doppler evaporating rain echo
b a radar echo from a splitting storm
c. a stationary radar echo from mountains or other surface features
d. a long-lived intense storm with repeated damaging downbursts
e. a new Toyota sports car for chasing tornadoes

Back 186

d. a long-lived intense storm with repeated damaging downbursts

Front 187

43. A flash flood is most likely to be triggered by heavy rains that develop in a precipitation efficient
atmosphere, that is, an atmosphere that features:
a. high values of precipitable water
b. high relative humidity
c. warm thunderstorm base
d. All of the above are correct.
e. None of the above is correct.

Back 187

d. All of the above are correct

Front 188

44. The number one weather-related killer of people in North America is:
a. flooding
b. lightning
c. tornadoes
d. hail
e. downbursts

Back 188

b. lightning

Front 189

45. The size of a hailstone depends on
a. speed of updraft in cloud
b. surface pressure
c. direction of surface wind
d. relative humidity of air
e. lightning

Back 189

a. speed of updraft in cloud

Front 190

46. Which of the following is not one of the four principal heat sources or sinks during hailstone growth?
a. latent heat release
b. radiative heat transfer
c. evaporative/sublimative heat transfer
d. sensible heat transfer
e. convective heat transfer

Back 190

b. radiative heat transfer

Front 191

47. A cylindrical hailshaft is 3 km in diameter and is travelling at 36 km/h. What is the maximum duration
of the resulting hailfall at a point?
a. 1 minute
b. 5 minutes
c. 12 minutes
d. 36 minutes
e. 1 hour

Back 191

b. 5 minutes

Front 192

48. What is a hodograph?
a. a diagram showing of the movement of hailswaths
b. a diagram showing the movement of a hailstones
c. a diagram showing the airflow in a hailstorm
d. a diagram connecting the endpoints of wind vectors at various heights
e. a diagram of the radar reflectivity in polar coordinates.

Back 192

d. a diagram connecting the endpoints of wind vectors at various heights

Front 193

49. A hailstone 1 cm in diameter has a terminal fall velocity of 14 m/s. What is the terminal fall velocity of
a hailstone 4 cm in diameter?
a. 14 m/s
b. 18 m/s
c. 28 m/s
d. 40 m/s
e. 56 m/s

Back 193

c. 28 m/s

Front 194

50. On average, in Alberta , the highest frequency of major hail days occurs in:
a. May
b. June
c. July
8
d. August
e. September

Back 194

c. July

Front 195

2. Lows are large scale weather systems which are also called________.

a. cyclones b. fronts c. anticyclones d. highs e. thunderstorm cells

Back 195

a. cyclones

Front 196

3. Highs that originate in northwestern Canada bring ___ , ____ weather in winter.

a. warm, moist b. warm, dry c. cold, moist d. cold, dry e. cold, stormy

Back 196

d. cold, dry

Front 197

4. In snowy conditions, a deicing fluid is sprayed on the wings and fuselage of aircraft
prior to take-off. The deicing fluid______________.

a. lowers the freezing point of water.
b. reduces the Bergeron-Findeiser process to melt the snow.
c. increases slightly the temperature of the wings and fuselage and thereby increases
the saturation vapour pressure with respect to ice
d. lowers the freezing point of water and increases the saturation vapour pressure
with respect to ice .
e. decreases the saturation vapour pressure with respect to ice.

Back 197

a. lowers the freezing point of water

Front 198

5. Environment Canada does not issue severe weather warnings for _____________.

a. intense lightning b. large hail c. heavy snowfall
d. tornadoes e. blizzards

Back 198

a. intense lightning

Front 199

6. Environment Canada issues a __________ when hazardous weather is imminent or
actually taking place.

a. weather watch b. weather warning c. discussion paper
d. weather prognosis e. weather map

Back 199

b. weather warning

Front 200

7. Weather radar gathers information about snow in clouds by measuring the:

a. energy emitted by falling precipitation particles
b. absorption characteristics of falling precipitation
c. amount of energy reflected back to the transmitter
d. amount of sunlight scattered off the precipitation
e. amount of solar energy passing through the cloud

Back 200

c. amount of energy reflected back to the transmitter

Front 201

8. Weather radar monitors the movement of ________.

a. polar orbiting weather satellites. b. geostationary weather satellites.
c. cloud particles. d. precipitation.
e. individual molecules.

Back 201

d. precipitation

Front 202

9. A(n) __________ satellite image is especially useful at night.

a. visible b. infrared c. geostationary
d. polar-orbiting e. water vapor

Back 202

b. infrared

Front 203

10. Meteorologists use water vapor satellite imagery to

a. determine the humidity in the air next to the Earth’s surface.
b. monitor the temperature of the tops of clouds.
c. monitor the angular momentum of the tops of clouds.
d. track the movement of water vapor at higher altitudes of the atmosphere.
e. measure the surface wind speed in a hurricane.

Back 203

d. track the movement of water vapor at higher altitudes of the atmosphere

Front 204

11. The Earth rotates through _____ degrees of _______every hour.

a. 15, longitude b. 15, latitude c. 30, longitude
d. 30, latitude e. 60 latitude

Back 204

a. 15, longitude

Front 205

12. Weather observations are made twice a day. Which of the following is incorrect?

a. 12 UTC b. 07 EST c. 05 MST d. 12 GMT e. 06 PST

Back 205

e. 06 PST

Front 206

13. The saturation vapor mixing ratio of air depends on ____________.

a. relative humidity and temperature b. vapor mixing ratio and temperature
c. pressure and temperature d. temperature only
e. vapor mixing ratio and pressure

Back 206

c. pressure and temperature

Front 207

14. As the temperature of a saturated (cloudy) air parcel falls, its relative humidity ______and the vapor mixing ratio __________.
a. increases, decreases b. decreases, does not change
c. does not change, increases d. does not change, decreases
e. increases, increases

Back 207

d. does not change, decreases

Front 208

15. If the temperature and the pressure of an unsaturated (clear) air parcel does not
change while its vapor mixing ratio increases, the density of the parcel ______ and
its relative humidity _______.

a. increases, increases b. decreases, increases
c. does not change, increases d. does not change, decreases
e. decreases, does not change

Back 208

b. decreases, increases

Front 209

16. If the mixing ratio of a parcel of air is 6 grams per kilo¬gram and the relative
humidity is 25 percent, the saturation mixing ratio is ______ grams per kilogram.

a. 1.5 b. 12 c. 8 d. 2 e. None of these is correct.

Back 209

e. None of these is correct

Front 210

17. An Environmental Lapse Rate of ______ Celsius degrees per 1000 meters is stable
for unsat¬urated air parcels.

a. 6 b. 4 c. 2
d. All of these are correct. e. None of these is correct.

Back 210

d. All of these are correct

Front 211

18. An Environmental Lapse Rate of ______ Celsius degrees per 1000 meters is stable
for clear air and unstable for cloudy air.

a. 3 b. 7 c. 13 d. 1 e. 11

Back 211

b. 7

Front 212

19. Horizontal curved lines on a Tephigram are _________.

a. isotherms b. saturated adiabats
c. isobars d. lines of constant saturation vapor mixing ratio.
e. fronts

Back 212

c. isobars

Front 213

20. As unsaturated air flows down the leeward slopes of a mountain range, ________.

a. the air temperature rises. b. the relative humidity decreases.
c. the saturation vapor pressure increases. d. All of the above are correct.
e. None of the above is correct.

Back 213

d. All of the above are correct

Front 214

21. Suppose the vapor mixing ratio of the cold outside air is the same as the vapor mixing
ratio of the warm air indoors. If the door is opened and the cold air replaces some of
the warm air, then the new relative humidity indoors would be_______.

a. higher than before b. the same as before
c. lower than before d. 0 %
e. twice its saturation vapor mixing ratio

Back 214

a. higher than before

Front 215

22. Which of these pairs of processes, working together, will make the atmosphere more
unstable?

a. cool the surface and warm the air aloft
b. cool the surface and cool the air aloft
c. warm the surface and cool the air aloft
d. warm the surface and warm the air aloft
e. cool the surface and moisten the air aloft

Back 215

c. warm the surface and cool the air aloft

Front 216

23. A parcel of unsaturated air descends adiabatically without mixing. A descend of 800
meter causes warming of __________ degrees Celsius.

a. - 8 b. 8 c. 0.8 d. 4 e. none of the these

Back 216

b. 8

Front 217

24. Consider the case of a very calm wind conditions near the ground. An increase in air
temperature results in ______________.

a. dewpoint decreases b. dewpoint increases
c. relative humidity decreases d. relative humidity increases
e. vapor mixing ratio decreases

Back 217

c. relative humidity decreases

Front 218

. Which one of the following cloud types would most likely be responsible for
producing heavy rain?

a. cumulus b. cumulonimbus c. altocumulus
d. cirrocumulus e. cirrus

Back 218

b. cumulonimbus

Front 219

A cloud that forms when warm air overrides cold air is

a. cumulus b. cumulonimbus. c. cirrostratus.
d. cumulus congestus. e. altocumulus

Back 219

c. cirrostratus

Front 220

27. Which one of the following clouds is most likely composed of ice crystals only?

a. stratus b. cumulonimbus c. cirrus
d. nimbostratus e. altocumulus

Back 220

c. cirrus

Front 221

28. Of the following cloud types, which one is the warmest?

a. cirrus b. cirrostratus c. cirrocumulus
d. altostratus e. stratus

Back 221

e. stratus

Front 222

. A cold cloud is composed of_________________ .

a. ice crystals
b. supercooled water droplets
c. a mixture of ice crystals and supercooled water drop¬lets
d. Any of the above is correct
e. None of the above is correct

Back 222

d. Any of the above is correct

Front 223

. The type of frozen precipitation sometimes produced by a summer thunderstorm is

a. snow. b. freezing rain. c. snow pellets. d. hail. e. sleet.

Back 223

d. hai

Front 224

The anvil top of a thunderstorm cloud is likely to be a ______ cloud that is composed
of ______.

a. warm, supercooled water droplets b. cold, liquid water droplets
c. cirrus, ice crystals d. altocumulus, water droplets
e. stratus, drizzle

Back 224

c. cirrus, ice crystals

Front 225

44. Of the following air masses, which one exhibits the greatest temperature change
between winter and summer?

a. maritime tropical b. continental polar c. maritime polar
d. continental tropical e. all the same

Back 225

b. continental polar

Front 226

45. As a warm front approaches, clouds appear in which one of the following sequences?

a. cirrus, altostratus, stratus b. stratus, altostratus, cirrus
c. cumulus, cumulonimbus, cirrus d. cumulonimbus, cumulus, nimbostratus
e. nimbostratus, cirrocumulus, cirrus

Back 226

a. cirrus, altostratus, stratus

Front 227

46 A front is a narrow zone of transition between air masses that contrast in

a. temperature. b. vapor mixing ratio .
c. density. d. Any of these is correct.
e. None of these is correct.

Back 227

d. Any of these is correct

Front 228

type of cloud associated with a fast-moving, well-defined cold front:

a. cirrus b. stratus
c. cumulonimbus d. cirrostratus
e. None of these is correct.

Back 228

c. cumulonimbus

Front 229

The type of front formed when the leading edge of cold air merges with a warm
front is known as ________________.

a. a cold front. b. a warm front.
c. a stationary front. d. an occluded front.
e. None of these is correct.

Back 229

d. an occluded front

Front 230

55. On weather maps observed precipitation is indicated by special symbols. The symbol
“ ” denotes ____ and “● “ denotes_____.

a. snow, drizzle b. drizzle, rain c. snow, rain
d. fog, snow e. rain shower , thunderstorm

Back 230

c. snow, rain

Front 231

. In a mature extra-tropical cyclone, drizzle is most likely to develop _________

a. to the northwest of the low center.
b. in the warm air behind the warm front.
c. in the cold air just ahead of the surface warm front.
d. in the warm air just ahead of the surface cold front.
e. right at the centre of lowest surface pressure.

Back 231

c. in the cold air just ahead of the surface warm front

Front 232

If at Edmonton airport the weather station reports a wind shift from northeast to
north and then northwest and a steady rain turning to snow flurries, the low center is
most likely moving

a. from west to east, north of Edmonton.
b. from northeast to southwest, north of Edmonton.
c. from southwest to northeast, east of Edmonton.
d. from southwest to northeast, north of Edmonton.
e. None of the above is correct.

Back 232

c. from southwest to northeast, east of Edmonton

Front 233

. Precipitation tends to be steady and persistent in the ______ sector of a mature extra-
tropical cyclone.

a. northeast b. northwest c. southeast d. southwest e. dry

Back 233

a. northeast

Front 234

A cyclonic bomb is defined as an extra-tropical cyclone whose central pressure
drops by at least ______ millibar in 24 hours.

a. 100 b. 24 c. 10 d. -24 e. -10

Back 234

b. 24

Front 235

Viewed from above in the Northern Hemisphere, surface winds blow ___________
about the center of a low pressure system.

a. clockwise and outward b. clockwise and inward
c. counterclockwise and outward d. counterclockwise and inward
e. clockwise and up

Back 235

d. counterclockwise and inward

Front 236

Symbol L on a weather maps denotes ____ and H denotes _____.

a. low wind speed , high wind speed b. low radiation, high radiation
c. low pressure, high pressure d. low temperature, high temperature
e. low pressure, high temperature

Back 236

c. low pressure, high pressure

Front 237

1. If the surface wind backs from northeast to north, Halifax (Nova Scotia) usually experiences
a. cold air advection.
b. warm air advection.
c. snow changing to rain.
d. falling air pressure.
e. hail.

Back 237

a. cold air advection

Front 238

2. If the surface wind veers from east to southeast to south, Halifax (Nova Scotia usually
experiences
a. cold air advection.
b. warm air advection.
c. rain changing to snow.
d. rising air pressure.
e. falling temperatures.

Back 238

b. warm air advection

Front 239

3. In a mature extratropical cyclone, fog and drizzle are most likely to develop
a. to the northwest of the low center.
b. in the warm air behind the warm front.
c. in the cold air just ahead of the surface warm front.
d. in the warm air just ahead of the surface cold front.
e. None of the above is correct.

Back 239

c. in the cold air just ahead of the surface warm front

Front 240

. If a weather station reports a wind shift from northeast to north and then northwest and a
steady rain turning to snow flurries, the low center is most likely moving
a. from west to east, north of the station.
b. from northeast to southwest, north of the station.
c. from southwest to northeast, east of the station.
d. from southwest to northeast, north of the station.
e. None of the above is correct.

Back 240

c. from southwest to northeast, east of the station

Front 241

Precipitation tends to be steady and persistent in the ______ sector of a mature extratropical
cyclone.
a. northeast
b. northwest
c. southeast
d. southwest

Back 241

a. northeast

Front 242

. The coldest sector of a mature extratropical cyclone is usually __________ of the cyclone
center.
a. northeast
b. northwest
c. southeast
d. southwest

Back 242

b. northwest

Front 243

The warmest sector of a mature extratropical cyclone is usually __________ of the cyclone
center.
a. northeast
b. northwest
c. southeast
d. southwest

Back 243

c. southeast

Front 244

The warmest air associated with a mature extratropical cyclone is usually located
a. at the low center.
b. southwest of the low center.
c. northwest of the low center.
d. southeast of the low center.
e. None of the above is correct.

Back 244

d. southeast of the low center

Front 245

What is the surface wind direction in the northwest sector of a mature extratropical cyclone?
a. southeast
b. east
c. south
d. northwest
e. southwest

Back 245

d. northwest

Front 246

Viewed from above, the surface wind circulation about an Alberta-type cyclone is
a. clockwise and outward.
b. clockwise and inward.
c. counterclockwise and outward.
d. counterclockwise and inward.
e. None of the above is correct.

Back 246

d. counterclockwise and inward

Front 247

A thunderstorm cloud:
a. cumulus
b. nimbostratus
c. cumulonimbus
d. stratus
e. altostratus

Back 247

c. cumulonimbus

Front 248

The mature stage of the life cycle of a thunderstorm cell is characterized by
a. updrafts only.
b. both updrafts and downdrafts.
c. cloud dissipation.
d. downdrafts only.
e. no updrafts and no downdrafts

Back 248

b. both updrafts and downdrafts

Front 249

.. The anvil top of a thunderstorm cloud is likely to be a ______ cloud that is composed of
______.
a. warm................supercooled water droplets
b. cold...............liquid water droplets
c. cirrus...............ice crystals
d. altocumulus...............water droplets
e. stratus...............drizzle

Back 249

c. cirrus...............ice crystals

Front 250

A gust front is associated with a(n)
a. intense thunderstorm.
b. land breeze.
c. chinook wind.
d. sea breeze.
e. None of these is correct

Back 250

a. intense thunderstorm

Front 251

. Appearance of a flat anvil top indicates that the developing thunderstorm cloud
(cumulonimbus) has reached a(n) ______ portion of the atmosphere.
a. unstable
b. neutral
c. conditionally stable
d. humid
e. extremely stable

Back 251

e. extremely stable

Front 252

. The dissipating stage of the life cycle of a thunderstorm cell is characterized by
a. updrafts only.
b. both updrafts and downdrafts.
c. hail and heavy rain.
d. the strongest surface winds.
e. downdrafts only.

Back 252

e. downdrafts only

Front 253

A mesoscale convective complex (MCC)
a. is the same as a supercell thunderstorm.
b. consists of numerous interacting thunderstorm cells.
c. is usually located just ahead of a fast-moving, well-defined cold front.
d. has a life expectancy of less than an hour.
e. is most likely to occur in the Pacific Northwest.

Back 253

b. consists of numerous interacting thunderstorm cells

Front 254

A squall line usually forms
a. along a stationary front.
b. in the cold air mass well behind a cold front.
c. in the mT air along or ahead of a cold front.
d. in the fog and cold air mass just north of a warm front.
e. None of these is correct.

Back 254

c. in the mT air along or ahead of a cold front

Front 255

Thunderstorm development is favored
a. by stable air.
b. over relatively cold surfaces.
c. by free convection alone.
d. by conditionally unstable maritime tropical air.
e. in arctic air.

Back 255

d. by conditionally unstable maritime tropical air

Front 256

Thunderstorm cells associated with a fast-moving, well-defined cold front
a. may be severe.
b. often occur as a squall line parallel to and ahead of the front.
c. often form an elongated cluster parallel to the front.
d. All of the above are correct.
e. None of the above is correct.

Back 256

d. All of the above are correct

Front 257

Thunderstorm development is triggered by
a. uplift along a well-defined cold front.
b. converging surface winds.
c. uplift of warm, humid air along mountain slopes.
d. forced convection.
e. Any of the above is correct.

Back 257

e. Any of the above is correct

Front 258

A feature sometimes present in thunderstorms that may prolong the mature stage is (are)
_____.
a. abundant ice nuclei at high altitudes.
b. an anvil top.
c. a cold downdraft.
d. precipitation.
e. a tilted updraft.

Back 258

e. a tilted updraft

Front 259

. A supercell thunderstorm is most likely to develop in the ______ sector of a mature extratropical
cyclone.
a. northwest
b. southeast
c. northeast
d. southwest
e. cold

Back 259

b. southeast

Front 260

A severe thunderstorm cell may be accompanied by__________.
a. damaging surface winds.
b. hail.
c. heavy rainfall.
d. frequent lightning.
e. Any of these is correct.

Back 260

e. Any of these is correct

Front 261

is a likely site for development of a severe thunderstorm cell.
b. separates hot, dry air from warm, humid air.
c. often occurs over Texas and Oklahoma.
d. All of the above are correct.
e. None of the above is correct.

Back 261

d. All of the above are correct

Front 262

. A thunderstorm cloud is a __________.
a. cumulus
b. nimbostratus
c. cumulonimbus
d. stratus
e. altostratus

Back 262

c. cumulonimbus

Front 263

On a clear day, the Earth's surface carries ______ electrical charge.
a. a positive
b. no
c. a negative
d. a double
e. a triple

Back 263

c. a negative

Front 264

. Lightning occurs________.
a. only when it is raining.
b. only during the towering cumulus stage of a thunderstorm life cycle.
c. most often in Michigan.
d. All of the above are correct.
e. None of the above is correct.

Back 264

e. None of the above is correct

Front 265

. Thunder is the consequence of ________.
a. a tilted updraft.
b. hail formation.
c. clouds bumping into one another.
d. lightning.
e. the gust front.

Back 265

d. lightning

Front 266

. Sound waves are considerably ______ than light waves so that thunder is heard ______
lightning is seen.
a. slower...............before
b. slower...............after
c. faster...............before
d. faster..............after

Back 266

b. slower...............after

Front 267

. A downburst _______.
a. is most likely to occur during the towering cumulus stage of a thunderstorm life cycle.
b. is never accompanied by virga.
c. is designated a microburst or macroburst depending on the distance impacted along the
ground.
d. All of the above are correct.
e. None of the above is correct.

Back 267

c. is designated a microburst or macroburst depending on the distance impacted along the
ground

Front 268

2. Microbursts are particularly dangerous for aircraft on takeoff or landing because they trigger
______.
a. lightning.
b. visibility-restricting rain.
c. large hailstones.
d. wind shear.
e. roll clouds.

Back 268

d. wind shear

Front 269

. A flash flood is most likely to be triggered by heavy rains that develop in a precipitation
efficient atmosphere, that is, an atmosphere that features _________.
a. high values of precipitable water
b. high relative humidity
c. a warm thunderstorm base
d. All of the above are correct.
e. None of the above is correct.

Back 269

d. All of the above are correct

Front 270

. Hail is typically produced by thunderstorm cells that are characterized by __________.
a. strong updrafts.
b. great vertical development.
c. an abundant supply of supercooled water droplets.
d. All of the above are correct.
e. None of the above is correct.

Back 270

d. All of the above are correct

Front 271

. Lows are large scale weather systems which are also called________.

a. cyclones b. fronts c. anticyclones d. highs e. thunderstorm cells

Back 271

a. cyclones

Front 272

Highs that originate in northwestern Canada bring ___ , ____ weather in winter.

a. warm, moist b. warm, dry c. cold, moist d. cold, dry e. cold, stormy

Back 272

d. cold, dry

Front 273

. In snowy conditions, a deicing fluid is sprayed on the wings and fuselage of aircraft
prior to take-off. The deicing fluid______________.

a. lowers the freezing point of water.
b. reduces the Bergeron-Findeiser process to melt the snow.
c. increases slightly the temperature of the wings and fuselage and thereby increases
the saturation vapour pressure with respect to ice
d. lowers the freezing point of water and increases the saturation vapour pressure
with respect to ice .
e. decreases the saturation vapour pressure with respect to ice.

Back 273

a. lowers the freezing point of water

Front 274

. Environment Canada does not issue severe weather warnings for _____________.

a. intense lightning b. large hail c. heavy snowfall
d. tornadoes e. blizzards

Back 274

a. intense lightning

Front 275

Environment Canada issues a __________ when hazardous weather is imminent or
actually taking place.

Back 275

b. weather warning

Front 276

. Weather radar gathers information about snow in clouds by measuring the:

a. energy emitted by falling precipitation particles
b. absorption characteristics of falling precipitation
c. amount of energy reflected back to the transmitter
d. amount of sunlight scattered off the precipitation
e. amount of solar energy passing through the cloud

Back 276

c. amount of energy reflected back to the transmitter

Front 277

Weather radar monitors the movement of ________.

a. polar orbiting weather satellites. b. geostationary weather satellites.
c. cloud particles. d. precipitation.
e. individual molecules.

Back 277

d. precipitation

Front 278

9. A(n) __________ satellite image is especially useful at night.

a. visible b. infrared c. geostationary
d. polar-orbiting e. water vapor

Back 278

b. infrared

Front 279

. Meteorologists use water vapor satellite imagery to

a. determine the humidity in the air next to the Earth’s surface.
b. monitor the temperature of the tops of clouds.
c. monitor the angular momentum of the tops of clouds.
d. track the movement of water vapor at higher altitudes of the atmosphere.
e. measure the surface wind speed in a hurricane.

Back 279

d. track the movement of water vapor at higher altitudes of the atmosphere

Front 280

11. The Earth rotates through _____ degrees of _______every hour.

a. 15, longitude b. 15, latitude c. 30, longitude
d. 30, latitude e. 60 latitude

Back 280

a. 15, longitude

Front 281

Weather observations are made twice a day. Which of the following is incorrect?

a. 12 UTC b. 07 EST c. 05 MST d. 12 GMT e. 06 PST

Back 281

e. 06 PST

Front 282

. The saturation vapor mixing ratio of air depends on ____________.

a. relative humidity and temperature b. vapor mixing ratio and temperature
c. pressure and temperature d. temperature only
e. vapor mixing ratio and pressure

Back 282

c. pressure and temperature

Front 283

14. As the temperature of a saturated (cloudy) air parcel falls, its relative humidity ______and the vapor mixing ratio __________.

a. increases, decreases b. decreases, does not change
c. does not change, increases d. does not change, decreases
e. increases, increases

Back 283

d. does not change, decreases

Front 284

. If the temperature and the pressure of an unsaturated (clear) air parcel does not
change while its vapor mixing ratio increases, the density of the parcel ______ and
its relative humidity _______.

a. increases, increases b. decreases, increases
c. does not change, increases d. does not change, decreases
e. decreases, does not change

Back 284

b. decreases, increases

Front 285

. If the mixing ratio of a parcel of air is 6 grams per kilo¬gram and the relative
humidity is 25 percent, the saturation mixing ratio is ______ grams per kilogram.

a. 1.5 b. 12 c. 8 d. 2 e. None of these is correct.

Back 285

e. None of these is correct

Front 286

. An Environmental Lapse Rate of ______ Celsius degrees per 1000 meters is stable
for unsat¬urated air parcels.

a. 6 b. 4 c. 2
d. All of these are correct. e. None of these is correct.

Back 286

d. All of these are correct

Front 287

. An Environmental Lapse Rate of ______ Celsius degrees per 1000 meters is stable
for clear air and unstable for cloudy air.

a. 3 b. 7 c. 13 d. 1 e. 11

Back 287

b. 7

Front 288

. Horizontal curved lines on a Tephigram are _________.

a. isotherms b. saturated adiabats
c. isobars d. lines of constant saturation vapor mixing ratio.
e. fronts

Back 288

c. isobars

Front 289

As unsaturated air flows down the leeward slopes of a mountain range, ________.

a. the air temperature rises. b. the relative humidity decreases.
c. the saturation vapor pressure increases. d. All of the above are correct.
e. None of the above is correct

Back 289

d. All of the above are correct

Front 290

Suppose the vapor mixing ratio of the cold outside air is the same as the vapor mixing
ratio of the warm air indoors. If the door is opened and the cold air replaces some of
the warm air, then the new relative humidity indoors would be_______.

a. higher than before b. the same as before
c. lower than before d. 0 %
e. twice its saturation vapor mixing ratio

Back 290

a. higher than before

Front 291

Which of these pairs of processes, working together, will make the atmosphere more
unstable?

a. cool the surface and warm the air aloft
b. cool the surface and cool the air aloft
c. warm the surface and cool the air aloft
d. warm the surface and warm the air aloft
e. cool the surface and moisten the air aloft

Back 291

c. warm the surface and cool the air aloft

Front 292

. A parcel of unsaturated air descends adiabatically without mixing. A descend of 800
meter causes warming of __________ degrees Celsius.

a. - 8 b. 8 c. 0.8 d. 4 e. none of the these

Back 292

b. 8

Front 293

. Consider the case of a very calm wind conditions near the ground. An increase in air
temperature results in ______________.

a. dewpoint decreases b. dewpoint increases
c. relative humidity decreases d. relative humidity increases
e. vapor mixing ratio decreases

Back 293

c. relative humidity decreases

Front 294

. Which one of the following cloud types would most likely be responsible for
producing heavy rain?

a. cumulus b. cumulonimbus c. altocumulus
d. cirrocumulus e. cirrus

Back 294

b. cumulonimbus

Front 295

A cloud that forms when warm air overrides cold air is

a. cumulus b. cumulonimbus. c. cirrostratus.
d. cumulus congestus. e. altocumulus

Back 295

c. cirrostratus

Front 296

Which one of the following clouds is most likely composed of ice crystals only?

a. stratus b. cumulonimbus c. cirrus
d. nimbostratus e. altocumulus

Back 296

c. cirrus

Front 297

Of the following cloud types, which one is the warmest?

a. cirrus b. cirrostratus c. cirrocumulus
d. altostratus e. stratus

Back 297

e. stratus

Front 298

29. A cold cloud is composed of_________________ .

a. ice crystals
b. supercooled water droplets
c. a mixture of ice crystals and supercooled water drop¬lets
d. Any of the above is correct
e. None of the above is correct

Back 298

d. Any of the above is correct

Front 299

30. The type of frozen precipitation sometimes produced by a summer thunderstorm is

a. snow. b. freezing rain. c. snow pellets. d. hail. e. sleet.

Back 299

d. hail

Front 300

31. The anvil top of a thunderstorm cloud is likely to be a ______ cloud that is composed
of ______.

a. warm, supercooled water droplets b. cold, liquid water droplets
c. cirrus, ice crystals d. altocumulus, water droplets
e. stratus, drizzle

Back 300

c. cirrus, ice crystals

Front 301

. Increasing the mass of the raindrop above by 20% will increase its terminal
velocity from 20 cm/s to approximately _____ cm/s.

a. 20 b. 21 c. 22 d. 24 e. 30

Back 301

b. continental polar

Front 302

. Of the following air masses, which one exhibits the greatest temperature change
between winter and summer?

a. maritime tropical b. continental polar c. maritime polar
d. continental tropical e. all the same

Back 302

a. cirrus, altostratus, stratus

Front 303

. As a warm front approaches, clouds appear in which one of the following sequences?

a. cirrus, altostratus, stratus b. stratus, altostratus, cirrus
c. cumulus, cumulonimbus, cirrus d. cumulonimbus, cumulus, nimbostratus
e. nimbostratus, cirrocumulus, cirrus

Back 303

d. Any of these is correct

Front 304

46 A front is a narrow zone of transition between air masses that contrast in

a. temperature. b. vapor mixing ratio .
c. density. d. Any of these is correct.
e. None of these is correct.

Back 304

c. cumulonimbus

Front 305

47. A type of cloud associated with a fast-moving, well-defined cold front:

a. cirrus b. stratus
c. cumulonimbus d. cirrostratus
e. None of these is correct.

Back 305

c. cumulonimbus

Front 306

48. The type of front formed when the leading edge of cold air merges with a warm
front is known as ________________.

a. a cold front. b. a warm front.
c. a stationary front. d. an occluded front.
e. None of these is correct.

Back 306

d. an occluded front

Front 307

On weather maps observed precipitation is indicated by special symbols. The symbol
“ ” denotes ____ and “● “ denotes_____.

a. snow, drizzle b. drizzle, rain c. snow, rain
d. fog, snow e. rain shower , thunderstorm

Back 307

c. snow, rain

Front 308

56. In a mature extra-tropical cyclone, drizzle is most likely to develop _________

a. to the northwest of the low center.
b. in the warm air behind the warm front.
c. in the cold air just ahead of the surface warm front.
d. in the warm air just ahead of the surface cold front.
e. right at the centre of lowest surface pressure.

Back 308

c. in the cold air just ahead of the surface warm front

Front 309

. If at Edmonton airport the weather station reports a wind shift from northeast to
north and then northwest and a steady rain turning to snow flurries, the low center is
most likely moving

a. from west to east, north of Edmonton.
b. from northeast to southwest, north of Edmonton.
c. from southwest to northeast, east of Edmonton.
d. from southwest to northeast, north of Edmonton.
e. None of the above is correct.

Back 309

c. from southwest to northeast, east of Edmonton

Front 310

58. Precipitation tends to be steady and persistent in the ______ sector of a mature extra-
tropical cyclone.

a. northeast b. northwest c. southeast d. southwest e. dry
. Precipitation tends to be steady and persistent in the ______ sector of a mature extra-
tropical cyclone.

* a. northeast b. northwest c. southeast d. southwest e. dry

Back 310

a. northeast

Front 311

A cyclonic bomb is defined as an extra-tropical cyclone whose central pressure
drops by at least ______ millibar in 24 hours.

a. 100 b. 24 c. 10 d. -24 e. -10

Back 311

b. 24

Front 312

Viewed from above in the Northern Hemisphere, surface winds blow ___________
about the center of a low pressure system.

a. clockwise and outward b. clockwise and inward
c. counterclockwise and outward d. counterclockwise and inward
e. clockwise and up

Back 312

d. counterclockwise and inward

Front 313

Symbol L on a weather maps denotes ____ and H denotes _____.

a. low wind speed , high wind speed b. low radiation, high radiation
c. low pressure, high pressure d. low temperature, high temperature
e. low pressure, high temperature

Back 313

c. low pressure, high pressure