Deck 9: Air Masses and Fronts

Question 1

An air mass is characterized by similar properties of __________ and __________ in any horizontal direction

A)temperature,pressure
B)pressure,moisture
C)winds,moisture
D)temperature,moisture

Answer 1

D

Question 2

A cold front that moves into New England from the east or northeast is called:

A)a cold occluded front.
B)an oceanic front.
C)a nor'easter.
D)a "back door" cold front.

Answer 2

D

Question 3

An upper-air front involves downward motion of the:

A)tropopause.
B)stratopause.
C)low-level jet.
D)both a and c

Answer 3

A

Question 4

Before the passage of a cold front the pressure normally __________,and after the passage of a cold front the pressure normally __________.

A)drops,drops
B)drops,rises
C)rises,rises
D)rises,drops

Question 5

What type of weather front would be responsible for the following weather forecast: "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."

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

Question 6

The greatest contrast in both temperature and moisture will occur along the boundary separating which air masses?

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

Question 7

What type of air mass would be responsible for refreshing cool,dry breezes after a long summer hot spell in the Central Plains?

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

Question 8

In the Southern Hemisphere,

A)air rises steeply ahead of a warm front,and gradually ahead of a cold front.
B)cold,warm and occluded fronts are associated with high pressure systems.
C)precipitation associated with warm fronts tends to be brief and intense.
D)precipitation associated with warm fronts tends to be gentle and prolonged.

Question 9

During the winter as you travel toward a warm front,the most likely sequence of weather you would experience is:

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

Question 10

What type of weather front would be responsible for the following weather forecast: "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 easterly today becoming southeasterly tonight and southwesterly tomorrow."

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

Question 11

At a warm front,the warm air:

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

Question 12

Which of the following statements is most plausible?

A)In winter,cP source regions have higher temperatures than mT source regions.
B)In summer,mP source regions have higher temperatures than cT source regions.
C)In winter,cA source regions have lower temperatures than cP source regions.
D)In summer,mT source regions have lower temperatures than mP source regions.
E)All the statements are equally plausible.

Question 13

The air mass with the highest actual water vapor content is:

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

Question 14

Occluded fronts may form as:

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

Question 15

On a weather map,the transition zone between two air masses with sharply contrasting properties is marked by:

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

Question 16

A good source region for an air mass would be:

A)mountains with deep valleys and strong surface winds.
B)generally flat areas of uniform composition with light surface winds.
C)hilly with deep valleys and light winds.
D)generally flat area of uniform composition with strong surface winds.

Question 17

Which air mass would show the most dramatic change in both temperature and moisture content as it moves over a large body of very warm water?

A)cT in summer
B)cP in winter
C)mP in winter
D)mT in summer

Question 18

What type of air mass would be responsible for daily afternoon thunderstorms along the Gulf Coast?

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

Question 19

What type of air mass would be responsible for hot,muggy summer weather in the eastern half of the United States?

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

Question 20

One would expect a cP air mass to be:

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

Question 21

Is it possible for a stationary front to produce precipitation? If so,would you expect to find the precipitation on the warm or the cold air side of the front?

Question 22

A stationary front does not move because the winds blow parallel to the front.

Question 23

During the spring,a mP air mass would most likely bring record-breaking high temperatures to the eastern half of the United States.

Question 24

List the four basic types of air masses.Give an example of where each type could originate and describe how each air mass could affect local weather conditions if it moved into your region.

Question 25

When a warm and cold air mass collide,why is the warm air is forced upward?

Question 26

Clear sunny days with very cold nights would be associated with a cP air mass.

Question 27

Explain how,using no meteorological instruments other than your eyes,you could identify the passage of an occluded front.

Question 28

A dryline is a stalled cold front.

Question 29

Describe some of the changes in weather conditions (winds,temperature,clouds,precipitation,pressure changes)that you would expect to observe as a cold front approaches and passes through your location.

Question 30

The origin of cP and cA air masses that enter the United States is northern Siberia.

Question 31

When cP air moves into western Washington,western Oregon,and California fro the east,the air mass is warmer at the surface than it was originally because the air sinks,is compressed,and warms.

Question 32

What type of clouds,if any,would you expect to see form when a cP air mass moves across warm water? Would conditions be any different when mT air moves across a cold land surface? What types of clouds would form in this latter case?

Question 33

Explain why the observation of a halo around the moon or sun could forewarn of the arrival of a warm front.

Question 34

During the winter,an air mass that moves into coastal sections of Oregon and Washington from the northwest would most likely be maritime Polar.

Question 35

Draw side views of a typical warm and cold front.Indicate the temperatures of the separate air masses and show their directions of motion.What types of clouds would you expect to find and where? Where would you expect precipitation to occur?

Question 36

Compared to an mP air mass,mT air is colder and drier.

Question 37

Fronts are associated with high pressure.

Question 38

How would a warm front,a cold front,and a center of low pressure appear on a surface weather map in the Southern Hemisphere?

Question 39

Without considering changes in temperature,how are the weather conditions accompanying a cold frontal passage different from those associated with the passage of a warm front?

Question 40

The rising of warm air up and over cold air is called overrunning.

Question 41

What types of weather changes accompany the passage of a dryline (dew point front)?