Deck 10: Mid-Latitude Cyclonic Storms

Question 1

The type of weather system known as a "mid-latitude cyclone" cannot form over the tropical ocean because:

A)surface temperature contrasts are not large.
B)the ocean surface has a lot of waves.
C)the Coriolis force is weak in the tropics.
D)both (a)and (b)
E)both (a)and (c)

Answer 1

E

Question 2

When an upper-level low lies directly above a surface low:

A)the surface low will probably weaken.
B)thunderstorms will develop.
C)a wave cyclone will begin to form.
D)the pressure of the surface low will decrease.
E)cyclogenesis will occur.

Answer 2

A

Question 3

Atmospheric shortwaves usually move __________ at a speed that is __________ than longwaves.

A)east to west,faster
B)west to east,faster
C)east to west,slower
D)west to east,slower

Answer 3

B

Question 4

For a surface storm system to intensify,the upper-level low (or trough)should be located to the __________ of the surface low.

A)north
B)south
C)east
D)west

Question 5

Strong storms that develop over water,poleward of the polar front,are called:

A)nor'easters.
B)upslope lows.
C)lee-side lows.
D)polar lows.
E)none of the above

Question 6

On a surface weather map that shows an open wave cyclone,the warm sector can be observed:

A)ahead of an advancing cold front.
B)behind an advancing cold front.
C)ahead of an advancing cold-occluded front.
D)behind an advancing cold-occluded front.
E)ahead of an advancing warm front.

Question 7

For cyclogenesis to occur along a frontal wave,the winds aloft directly above the wave should be:

A)diverging.
B)converging.
C)blowing straight from west to east.
D)increasing in speed uniformly over a broad area.

Question 8

Like hurricanes,__________ have a clear area in their center.

A)polar lows
B)cut-off lows
C)conveyer belts
D)wrap-around bands

Question 9

According to the model of the life cycle of a wave cyclone,the storm system is normally most intense:

A)as a frontal wave.
B)as a stable wave.
C)as an open wave.
D)as a stationary wave.
E)when the system first becomes occluded.

Question 10

Cyclogenesis is the __________ of a mid-latitude cyclone.

A)development or strengthening
B)weakening or dissipation
C)term for the exact midpoint
D)none of the above

Question 11

An upper-level pool of cold air that has broken away from the main flow is called:

A)a cut-off low.
B)a shortwave.
C)a wave cyclone.
D)a lee-side low.

Question 12

Which region is not considered to be a region where cyclogenesis often occurs:

A)eastern slopes of the Rocky Mountains.
B)Atlantic Ocean near Cape Hatteras,North Carolina.
C)California.
D)the Great Basin of the United States.
E)Gulf of Mexico.

Question 13

Which of the following is not associated with rising air motions?

A)overrunning
B)convergence of air at the surface
C)convergence of air aloft
D)divergence of air aloft

Question 14

Northeasters (or nor'easters)are midlatitude storms commonly found:

A)along the Pacific coast of North America.
B)along the Atlantic coast of North America.
C)along the Gulf coast of North America.
D)both a and b

Question 15

If the flow of air into a surface low pressure area is greater than the divergence of air aloft,the surface pressure in the center of the low will:

A)increase.
B)decrease.
C)remain the same.
D)deepen.

Question 16

In the polar front theory of a developing wave cyclone,energy for the storm is usually derived from all but one of the following:

A)rising of warm air and the sinking of cold air
B)latent heat of condensation
C)an increase in surface winds
D)heat energy stored in the ground

Question 17

When a deep upper-level trough is located to the east of a surface anticyclone,the surface anticyclone will tend to move toward the:

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

Question 18

When upper-level divergence of air above a surface low pressure area is stronger than the convergence of surface air,the surface pressure will __________ and the storm itself will __________.

A)increase,intensify
B)increase,dissipate
C)decrease,intensify
D)decrease,dissipate

Question 19

If the outflow of air around a surface high pressure area is greater than the convergence of air aloft,you would observe:

A)in increase in pressure in the center of the high.
B)movement of the high toward the northeast.
C)a decrease in the central pressure.
D)strengthening in the high.

Question 20

Developing low pressure areas generally have __________ air near the surface and __________ air aloft.

A)converging,diverging
B)diverging,converging
C)converging,converging
D)diverging,diverging

Question 21

Suppose you observe a middle-latitude cyclone on the surface weather chart.What kind(s)of weather chart(s)would you want to examine to determine whether the cyclone is likely to strengthen or decay over the next 24 hours? What information would you hope to gain from each chart type?

Question 22

What is cyclogenesis? List some of the regions in the United States where cyclogenesis is common.

Question 23

A lee-side low forms on the downwind side of a mountain.

Question 24

The polar front theory was developed by the famous explorer Magellan in the 1500s.

Question 25

Describe or illustrate the various phases in the life cycle of a middle latitude storm according to the polar front theory.

Question 26

If lows and highs aloft were always directly above lows and highs at the surface,the surface systems would quickly disspiate.

Question 27

The development or strengthening of a middle latitude storm system is called frontolosys.

Question 28

When making a weather forecast,which kind of chart is more important: a surface chart or a 500 mb chart? Why?

Question 29

Longwaves in the middle and upper troposphere usually have lengths on the order of thousands of kilometers.

Question 30

Divergence in the polar jet stream draws warm surface air upward.

Question 31

Using Figure 10.17,can you identify regions of cold advection? Warm advection? Explain your reasoning.

Question 32

The piling up of air above a region is called thickening.

Question 33

A 'building anticyclone' means the central pressure is increasing.

Question 34

List some of the reasons why the polar front theory doesn't apply to storms in the tropics.

Question 35

Describe some of the ways in which the upper-level wind flow pattern can influence the development and movement of a middle latitude storm system.

Question 36

Sketch a 500 mb chart that clearly shows a trough and a ridge.Where would you expect to find converging and diverging wind motions? Below what point on your 500 mb chart would you expect middle latitude storm development to occur?

Question 37

With the aid of a diagram,show why an intensifying surface low pressure center which is located just east of a deep upper-level trough will often move in a northeasterly direction.

Question 38

What does the term "shortwave" refer to? Why is it important to locate and follow the movements of atmospheric shortwaves? How is this done? How is a shortwave different from a "longwave?"

Question 39

A surface low pressure area with a deep upper-level trough to the west will tend to move toward the southwest.

Question 40

Lee-side lows are thermal lows that form due to surface heating over deserts.