Deck 11: Air Masses and Fronts

Question 1

Which of the following types of air masses is mainly responsible for persistent cold, damp weather with drizzle along the east coast of North America?

A)mP
B)mT
C)cT
D)cP

Answer 1

A

Question 2

Which of the following terms refers to the situation when an mT air mass lies above a cold ground surface?

A)occluded
B)unstable
C)stationary
D)stable

Answer 2

D

Question 3

What do the continental polar (cP) and continental arctic (cA) air masses have in common?

A)They both bring strong thunderstorms.
B)They both form in summer only.
C)They both originate over polar oceans.
D)They both tend to be dry.

Answer 3

D

Question 4

Suppose a weather forecast states the following: Increasing high cloudiness and cold this morning; clouds increasing and lowering this afternoon, with a chance of snow or rain tonight; precipitation ending tomorrow morning; turning much warmer; winds light and easterly today, becoming southeasterly tonight and southwesterly tomorrow. Which of the following types of weather fronts would be responsible for this forecast?

A)cold front
B)stationary front
C)warm-type occluded front
D)warm front

Question 5

Which of the following statements applies to a warm front?

A)In winter it is usually associated with cumulus clouds.
B)It has cold air ahead of it.
C)It is coloured blue on a weather map.
D)It normally moves faster than a cold front.

Question 6

Which of the following statements gives the main reason why the wintertime mP air masses are less common along the North American Atlantic coast than along the Pacific coast?

A)The water is warmer along the Atlantic coast.
B)The prevailing winds aloft are westerly.
C)The source region for mP air on the Atlantic coast is western Europe.
D)The water is colder along the Pacific coast.

Question 7

Which of the following factors is the only one indicated on the station model of past weather conditions?

A)dew point
B)temperature
C)cloud cover
D)pressure tendency

Question 8

Which of the following sequences gives the order of weather conditions you would likely experience in winter as you travel toward a warm front?

A)rain, snow, sleet, freezing rain
B)snow, sleet, freezing rain, rain
C)snow, freezing rain, hail, sleet
D)freezing rain, snow, sleet, rain

Question 9

Which of the following statements describes weather fronts in the southern hemisphere?

A)Warm fronts are associated with high-pressure systems.
B)Precipitation associated with warm fronts tends to be brief and intense.
C)Precipitation associated with warm fronts tends to be gentle and prolonged.
D)Cold and occluded fronts are associated with high-pressure systems.

Question 10

On a weather map, which of the following types of weather fronts are drawn to indicate where cold air is replacing cool air?

A)cold front
B)warm-type occluded front
C)cold-type occluded front
D)warm front

Question 11

Why do stationary fronts often exist along the Rocky Mountains?

A)Overrunning leads to the formation of clouds.
B)Air sinks on the east side of the mountains and becomes warmer.
C)Cold air masses cannot move up and over the mountain.
D)Air rapidly rises up the slopes of the mountains during the afternoon.

Question 12

Which of the following areas provides a good regional source for an air mass?

A)mountain areas with deep valleys and strong surface winds
B)generally flat areas of uniform composition with light surface winds
C)mountain areas with deep valleys and light surface winds
D)generally flat areas of uniform composition with strong surface winds

Question 13

During which of the following conditions do lake-effect snows best develop around the Great Lakes?

A)late fall and early winter when moist, polar air sweeps in from the east
B)early spring when moist, tropical air moves over the frozen lakes
C)late fall and early winter when cold, dry, polar air moves over the relatively warm water
D)middle winter when the unseasonably warm air mass moves over the cold water

Question 14

Suppose a weather forecast states the following: Cool today, with rain becoming heavy by this afternoon; slightly warmer tomorrow; winds southeasterly, becoming westerly to northwesterly by tomorrow morning. Which of the following types of weather fronts would be responsible for this forecast?

A)cold-type occluded front
B)cold front
C)warm-type occluded front
D)warm front

Question 15

In which of the following regions do continental tropical air masses typically occur?

A)northern Mexico and eastern Canada
B)the Gulf of Mexico and the southeastern United States
C)northern Mexico and the southwestern United States
D)the Gulf of Mexico and the southwestern United States

Question 16

Which of the following types of air masses is the coldest of all?

A)mT
B)mP
C)cA
D)cT

Question 17

Clear, sunny days with very cold nights are associated with which of the following types of air masses?

A)cA
B)cT
C)mP
D)mT

Question 18

Suppose a weather forecast states the following: Light rain and cold today with temperatures just above freezing; southeasterly winds shifting to westerly tonight; turning colder, with rain becoming mixed with snow, then changing to snow. Which of the following types of weather fronts would be responsible for this forecast?

A)cold-type occluded front
B)warm-type occluded front
C)cold front
D)warm front

Question 19

Which of the following types of air masses is mainly responsible for snow showers on the western slopes of the Rockies?

A)cP
B)cA
C)mP
D)mT

Question 20

Which of the following expressions is the designation for a cool, moist air mass?

A)cP
B)cT
C)mP
D)mT

Question 21

At which of the following positions is falling pressure most likely observed?

A)1
B)1 and 2
C)1, 2, and 3
D)1, 2, 3, and 4

Question 22

Which of the following describes the wind shift that most likely occurs as a "back door" cold front moves through the Maritimes?

A)shift from easterly to westerly
B)shift from southerly to westerly
C)shift from southeasterly to southwesterly
D)shift from westerly to northeasterly

Question 23

During the spring, which of the following types of air masses most likely brings record-breaking high temperatures to eastern North America?

A)cP
B)mT
C)mP
D)cT

Question 24

Surface Map
Which of the following options gives the names of the types of air masses that the upper air flow brings into Atlantic Canada?

A)cP
B)mP
C)cA
D)mT

Question 25

Which of the following terms refers to the rising of warm air up and over cold air?

A)overrunning
B)frontolysis
C)occlusion
D)frontogenesis

Question 26

Surface Weather Map
​
​
Refer to the above surface weather map.
At which of the following positions is the sky most likely clearing?

A)1
B)2
C)3
D)4

Question 27

The greatest contrast in both temperature and moisture occurs along the boundary between which of the following air masses?

A)cA and mT
B)cP and cT
C)mP and mT
D)cP and mT

Question 28

Which of the following types of air masses is mainly responsible for hot, muggy summer weather in southern Ontario?

A)cT
B)mP
C)cP
D)mT

Question 29

Which of the following statements explains why a stationary front does not move?

A)The winds blow parallel to the front.
B)The front is between high and low pressure.
C)The winds blow against each other and are of equal strength.
D)The winds on both sides of the front are calm.

Question 30

Surface Weather Map
​
​
Refer to the above surface weather map.
At which of the following positions is the warm sector located?

A)1
B)2
C)3
D)4

Question 31

Which of the following describes the air conditions around a cold-type occluded front?

A)cold surface air behind it
B)warm surface air behind it
C)cold air rising above warmer air
D)cold surface air ahead of it

Question 32

Which of the following types of air masses has the highest actual water vapour content?

A)cP
B)mP
C)mT
D)cT

Question 33

Which of the following is considered a good source region for a continental air mass?

A)British Columbia
B)Canadian Prairies
C)Lake Huron
D)Gulf of St.Lawrence

Question 34

Surface Map
Which of the following types of air masses form over North America in summer only?

A)mP
B)cP
C)mT
D)cT

Question 35

Which of the following explains why thunderstorms along cold fronts are more severe than thunderstorms along warm fronts?

A)Uplift is more rapid along cold fronts.
B)Cold air has a greater capacity for moisture.
C)Cold fronts move more slowly than warm fronts.
D)There is greater turbulence ahead of cold fronts due to the higher air pressure.

Question 36

Which of the following is an accurate statement about lake-effect snows?

A)They are most common in early spring.
B)They are caused by mP air masses.
C)They are enhanced by a large fetch.
D)They result in heavy snowfall on the north sides of the lakes.

Question 37

Which of the following conditions refers to a maritime polar air mass that reaches the Pacific Coast?

A)warm air
B)absolutely unstable air
C)moist air
D)absolutely stable air

Question 38

Suppose a weather forecast states the following: Increasing cloudiness and warm today, with the possibility of showers by this evening; turning much colder tonight; winds southwesterly, becoming gusty and shifting to northwesterly by tonight. Which of the following types of weather fronts would be responsible for this forecast?

A)cold front
B)stationary front
C)cold-type occluded front
D)warm front

Question 39

Surface Weather Map
Refer to the above surface weather map.
Between which of the following points is a warm front positioned?

A)between 3 and 4
B)between 1 and 2
C)between 2 and 5
D)between 2 and 3

Question 40

During the course of a day, the afternoon was sunny and warm while rain showers occurred in the evening. This was followed by clear skies and a drop in temperatures that night. Which of the following had most likely passed through that day?

A)warm front
B)cold front
C)dryline
D)stationary front

Question 41

In British Columbia, which of the following types of air masses is mainly responsible for heavy rain and snow?

A)cP
B)cA
C)mP
D)mT

Question 42

Which of the following types of air masses is mainly responsible for hot, dry summer weather in southern Arizona?

A)cP
B)mP
C)mT
D)cT

Question 43

Which of the following situations provides an example of a "back door" cold front?

A)a cold front moving into British Columbia from the Pacific Ocean
B)a cold front moving into the desert southwest from northern Mexico
C)a cold front moving into the Maritimes from the Atlantic Ocean
D)a cold front moving in a clockwise direction around a low pressure centre

Question 44

Referring to the diagram below, which of the following options states the name of the front and the position of the coldest air? ​

A)stationary front, with coldest air at 1
B)stationary front, with coldest air at 2
C)occluded front, with coldest air at 1
D)occluded front, with coldest air at 2

Question 45

Referring to the diagram, which of the following types of fronts is represented as a side view? ​
​
​

A)cold front
B)occluded front
C)warm front
D)stationary front

Question 46

Which of the following types of air masses most likely occurs during the winter when an air mass moves into coastal sections of British Columbia from the northwest?

A)cP
B)mA
C)cT
D)mT

Question 47

Which of the following statements accurately compares an average cold front to an average warm front?

A)Generally, precipitation covers a much broader area with a cold front.
B)Especially in summer, cumuliform clouds are often associated with cold fronts.
C)Generally, cold fronts move slower than warm fronts.
D)Generally, warm fronts have steeper slopes than cold fronts.

Question 48

Which of the following regions is the origin of the continental arctic (cA) air mass that enters Canada?

A)northern Canada and Alaska
B)northern Atlantic Ocean
C)northern Siberia
D)Antarctica

Question 49

Which of the following is essential for lake-effect snow to occur near the Great Lakes?

A)cold water
B)open water
C)warm air
D)ice-covered water

Question 50

From which of the following directions is the wind at point 3 most likely coming from?

A)northeast
B)southeast
C)northwest
D)southwest

Question 51

Thunderstorms most likely form along which of the following weather fronts in winter?

A)occluded fronts
B)cold fronts
C)stationary fronts
D)warm fronts

Question 52

The greatest contrast in both temperature and moisture occurs along the boundary between which of the following air masses?

A)mT and cP
B)cP and cT
C)mP and cT
D)mP and mT

Question 53

Which of the following characterizes stationary fronts?

A)They are often associated with cloud cover.
B)They occur within a single air mass.
C)They occur when two cold fronts meet.
D)They move at the same speed as cold fronts.

Question 54

Record-breaking low temperatures are associated with which of the following types of air masses?

A)cP
B)mP
C)cT
D)mT

Question 55

Surface Weather Map
Refer to the above surface weather map.
Between which of the following points is an occluded front positioned?

A)between 3 and 4
B)between 2 and 3
C)between 2 and 5
D)between 1 and 2

Question 56

In which of the following conditions is a frontal inversion likely best observed?

A)with a warm front in winter
B)with a warm front in summer
C)with a cold front is summer
D)with a stationary front in winter

Question 57

In which of the following air masses do cumuliform clouds most likely develop?

A)cP air mass moving over warm water
B)mT air mass moving over cold land surface
C)cT air mass moving over a mountain range
D)cT air mass moving over cold water

Question 58

Which of the following types of fronts is represented by alternating lines of blue and red on a surface weather map?

A)cold front
B)warm front
C)stationary front
D)occluded front

Question 59

Which of the following describes the likely formation of occluded fronts?

A)A cold front overtakes a warm front.
B)A warm front overtakes a cold front.
C)Overrunning occurs along a warm front.
D)A cold front overtakes a squall line.

Question 60

Which of the following undergoes a downward motion during an upper-air front?

A)tropopause
B)low-level jet
C)mesopause
D)stratopause

Question 61

Surface Weather Map
​
​
Refer to the above surface weather map.
Which of the following would you expect to see as a cold front approaches?

A)altostratus clouds forming
B)winds blowing from the north
C)skies clearing
D)air pressure falling

Question 62

If the above diagram represents a front in the southern hemisphere, which of the following is a correct statement about front A? ​

A)It is a cold front moving toward the north.
B)It is a cold front moving toward the south.
C)It is a warm front moving toward the north.
D)It is a warm front moving toward the south.

Question 63

On a weather map, which of the following signifies the transition zone between two air masses with sharply contrasting properties?

A)the letter "L"
B)the words "air mass weather"
C)the letter "H"
D)a front

Question 64

Which of the following statements best compares an mT air mass with an mP air mass?

A)An mT air mass is warmer and drier.
B)An mT air mass is warmer and moister.
C)An mT air mass is colder and drier.
D)An mT air mass is colder and moister.

Question 65

On a weather map, which of the following types of fronts is drawn in blue and represents a region where colder air is replacing warmer air?

A)cold-type occluded front
B)warm-type occluded front
C)cold front
D)warm front

Question 66

Which of the following applies to an occluded front?

A)It marks a zone of shifting wind.
B)At the surface, it is always followed by warmer air.
C)It is coloured blue on a surface weather map.
D)It is often associated with a narrow band of precipitation.

Question 67

Which of the following terms refers to a cold front that moves into the Maritimes from the east or northeast?

A)oceanic front
B)"back door" cold front
C)nor'easter
D)cold-occluded front

Question 68

Squall lines most often form ahead of which of the following types of weather fronts?

A)cold-type occluded front
B)warm-type occluded front
C)cold front
D)warm front

Question 69

Which of the following statements describes how a true cold front is represented on a weather map?

A)It is always followed by cooler air.
B)It is always followed by drier air.
C)It is always associated with precipitation.
D)It is always associated with a wind shift.

Question 70

A halo around the sun or moon indicates that rain may be on the way. Which of the following statements explains why this is the case?

A)A sharp drop in atmospheric pressure may occur.
B)A warm front may be approaching.
C)A cold front may be approaching.
D)A sudden rise in surface dew point temperature may occur.

Question 71

Which of the following statements accurately compares the temperatures of different source regions?

A)In summer, mT source regions have lower temperatures than mP source regions.
B)In winter, cP source regions have higher temperatures than mT source regions.
C)In winter, cA source regions have lower temperatures than cP source regions.
D)In summer, mP source regions have higher temperatures than cT source regions.

Question 72

Surface Map
Which of the following options gives the names of the types of air masses that the upper air flow brings into southern Ontario?

A)cP
B)cT
C)mP
D)mT

Question 73

Referring to a weather map, which of the following statements defines "frontogenesis"?

A)One front is about to overtake another front.
B)Severe thunderstorms will form along a front.
C)A front is regenerating or strengthening.
D)A front is in the process of dissipating.

Question 74

Which of the following correctly states the pressure changes as a cold front passes through an area?

A)The pressure drops in advance of the front and then rises after the front passes.
B)The pressure drops in advance of the front and then drops further after the front passes.
C)The pressure rises in advance of the front and then drops after the front passes.
D)The pressure rises in advance of the front and then rises further after the front masses.

Question 75

During which of the following conditions do lake-effect snows occur?

A)when an mT air mass moves over a warm body of water
B)when an mT air mass moves over a cold body of water
C)when a cP air mass moves over a cold body of water
D)when a cP air mass moves over a warm body of water

Question 76

Which of the following statements describes a cold front?

A)It marks the position of a trough of high pressure.
B)It has warm air behind it.
C)It marks a zone of shifting winds.
D)It is coloured purple on a weather map.

Question 77

Which of the following types of air masses is mainly responsible for heavy summer rain showers in southern Arizona?

A)mP
B)mT
C)cP
D)cT

Question 78

Which of the following conditions characterize a cP air mass?

A)cold and moist
B)warm and moist
C)warm and dry
D)cold and dry

Question 79

Surface Weather Map
Refer to the above surface weather map.
Between which of the following points is a cold front positioned?

A)between 1 and 2
B)between 2 and 3
C)between 2 and 5
D)between 3 and 4

Question 80

Which of the following describes the changes to the warm air at a warm front?

A)It rises and cools.
B)It sinks and cools.
C)It rises and warms.
D)It sinks and warms.